docs(docs): release v0.2.20

Add FEATURES.md and USAGE.md entries to the [0.2.20] changelog section.
No code changes — documentation reorganisation only.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

.gitea/workflows/ci.yml

@@ -0,0 +1,40 @@
+name: ci
+
+on:
+  push:
+    branches:
+      - '**'
+  pull_request:
+
+jobs:
+  ci:
+    name: vet, staticcheck, test, build
+    runs-on: ubuntu-latest
+    container:
+      image: golang:1.26-alpine
+
+    steps:
+      - name: Install tools
+        run: apk add --no-cache git
+
+      - name: Checkout
+        env:
+          TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          SERVER_URL: ${{ github.server_url }}
+          REPO: ${{ github.repository }}
+          REF: ${{ github.ref_name }}
+        run: |
+          git clone --depth 1 --branch "$REF" \
+            "$(echo "$SERVER_URL" | sed "s|https://|https://oauth2:${TOKEN}@|")/${REPO}.git" .
+
+      - name: vet
+        run: go vet ./...
+
+      - name: staticcheck
+        run: go tool staticcheck ./...
+
+      - name: test
+        run: go test ./...
+
+      - name: build
+        run: go build ./cmd/glint/...

CHANGELOG.md

@@ -5,10 +5,144 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/).
 This project uses [Semantic Versioning](https://semver.org).
 
-## [Unreleased]
+## [0.2.20] - 2026-06-14
 
 ### Added
 
+- **`glint explain <RULE>`** — new subcommand that prints the description, rationale, a bad-YAML example, and the corrected fix for any rule ID (GL001–GL043). `glint explain` with no argument lists all rules with ID, severity, and title. Rule IDs are case-insensitive (`gl007` and `GL007` are equivalent).
+
+- **`rules:if:` evaluated reachability (GL042)** — warns when every `rules:if:` condition in a job evaluates to false using the values of variables declared in the pipeline YAML, meaning the job can never be included in a pipeline run. The check is conservative: it only fires when all variables referenced in the `if:` expressions are explicitly declared in the YAML; predefined `CI_*` / `GITLAB_*` variables and undeclared variables are treated as unknown (may have any runtime value) to avoid false positives.
+
+- **`inherit:` completeness (GL043)** — warns when a job declares `inherit: default:` (boolean or list form) but the pipeline has no `default:` block, making the declaration a no-op. Also warns when the list form names fields (e.g. `[image, before_script]`) that are not actually set in the `default:` block — those list entries have no effect.
+
+- **`FEATURES.md`** — full feature reference extracted from the README: all 43 lint rules in categorised tables, include resolution capabilities, context simulation details, output format schemas, configuration reference, graph visualisation modes, and developer tools. The README `## Features` section replaced with a compact 6-line `## What it does` summary with a link to `FEATURES.md`.
+
+- **`USAGE.md`** — complete command-by-command usage reference extracted from the README: `glint check` with all output formats and examples, context simulation flags and predefined variable table, remote includes and token resolution, cache and offline mode, component reference format, `glint graph` modes, `glint explain` usage, project config (`.glint.yml`), and inline suppression. The README `## Usage` section replaced with the commands block and a single link to `USAGE.md`.
+
+## [0.2.19] - 2026-06-14
+
+### Added
+
+- **`.glint.yml` project config file** — glint now searches for a `.glint.yml` file starting from the pipeline file's directory and walking up to the first `.git` boundary. Supported keys:
+  - `ignore: [GL007, GL032]` — suppress rules globally for the project.
+  - `severity: {GL004: warning}` — override rule severity (`error`, `warning`, or `ignore`). `ignore` is equivalent to listing the rule in `ignore:`.
+  - `stages: [quality]` — declare extra stage names that are valid beyond those in the pipeline's own `stages:` block; jobs in these stages are not flagged by GL004.
+  - `token: glpat-xxx` — default GitLab personal access token (lower priority than the `--token` flag and `GITLAB_TOKEN` env var).
+  - `url: https://gitlab.example.com` — default GitLab instance URL.
+  - `cache_dir: ~/.cache/glint` — default cache directory for fetched remote includes.
+
+- **Inline suppression comments** — a `# glint: ignore RULE` comment placed immediately before a job definition suppresses that rule for the specific job. Multiple rules can be comma- or space-separated (`# glint: ignore GL007, GL032`). Use `# glint: ignore all` to suppress every finding for the job. Suppressions are scoped to the annotated job; pipeline-level findings are unaffected.
+
+## [0.2.18] - 2026-06-14
+
+### Added
+
+- **`--format json`** — `glint check` can now emit a structured JSON report instead of plain text. The schema (version `1`) includes `glint_version`, `pipeline`, a `findings` array (each finding has `rule`, `severity`, `file`, `line`, `job`, `message`), and a `summary` block (`total`, `errors`, `warnings`). An empty findings array is `[]`, not `null`. In this mode the human-readable summary line is written to stderr so stdout contains only the JSON payload.
+
+- **`--format sarif`** — emits a SARIF 2.1.0 JSON document (schema `https://json.schemastore.org/sarif-2.1.0.json`). The `runs[0].tool.driver` lists every unique rule ID found in findings; each `result` carries `ruleId`, `level` (`error`/`warning`), `message.text` (including the job name prefix), and `locations[0].physicalLocation` with `artifactLocation.uri` and `region.startLine` (when available). Pipeline-level findings without a file have no `locations` entry. This format is consumed natively by GitHub Code Scanning and GitLab SAST.
+
+- **`--format junit`** — emits a JUnit XML document compatible with CI test-report artifact parsers (GitLab: `artifacts:reports:junit`; GitHub: upload-artifact + test-reporter). Each finding becomes a `<testcase>` with a `<failure>` child whose `message` and `type` attributes carry the finding details. A clean pipeline produces a single passing `<testcase>` with no `<failure>` element.
+
+- **`--format github`** — emits GitHub Actions workflow-command annotation lines (`::error file=…,line=…,title=RULE::message` / `::warning …`). GitHub CI renders these as inline comments on the relevant file in pull requests. Pipeline-level findings without a file omit the `file=` parameter.
+
+- **Format validation** — an unknown `--format` value exits with code 2 and a helpful error message listing the valid formats.
+
+## [0.2.17] - 2026-06-14
+
+### Added
+
+- **Recursive include depth limit** — `resolveIncludes` now accepts a `depth` counter and returns a warning when the nesting depth exceeds 100 (matching GitLab's documented limit). This guards against pathologically deep include chains.
+
+- **Cycle detection for project and component includes** — `project:` and `component:` includes were not previously tracked in the `visited` map (only `local:` and `remote:` were). They are now registered before recursing into their sub-includes, preventing cross-file include cycles from causing infinite loops.
+
+- **`include: inputs:` substitution** — when a `component:` include entry has a `with:` block, all `$[[ inputs.KEY ]]` and `$[[ inputs.KEY | default('…') ]]` placeholders in the fetched template YAML are substituted with the corresponding values before parsing. Supported default value forms: `'single quoted'`, `"double quoted"`, bare booleans (`true`/`false`), and bare integers. Missing keys without a default become empty strings. This replaces the previous behaviour of leaving `$[[…]]` tokens in the YAML, which caused false-positive lint findings.
+
+- **Include cache (`--cache-dir`)** — pass `--cache-dir DIR` to `glint check` or `glint graph` to persist fetched remote templates (both `project:` and `component:` includes and `remote:` URLs) to a local directory. Cache entries are keyed by the SHA-256 of the full request coordinates (base URL + project + path + ref). The directory is created automatically on first use.
+
+- **Offline mode (`--offline`)** — pass `--offline` to skip all network calls. Remote includes not present in the cache are surfaced as warnings (same UX as "no token"). When `--offline` is set without an explicit `--cache-dir`, the default platform cache directory (`$XDG_CACHE_HOME/glint` or `~/.cache/glint`) is used automatically.
+
+## [0.2.16] - 2026-06-14
+
+### Added
+
+- **`services:` validation (GL034)** — the map form of a service entry requires a `name` key; emits an `ERROR` when absent. The optional `alias` field must be a valid DNS label (letters, digits, hyphens, and dots; must start and end with an alphanumeric character); invalid aliases emit an `ERROR`.
+
+- **`rules:changes` / `rules:exists` absolute path detection (GL035)** — emits a `WARNING` when a path in `rules:changes:` or `rules:exists:` starts with `/`. GitLab CI evaluates these paths relative to the repository root, so absolute paths can never match. Applies to both the list form and the `{paths: …}` map form.
+
+- **`timeout:` format validation (GL036)** — emits an `ERROR` when a job's `timeout:` (or the pipeline-level `default.timeout:`) is not a valid GitLab CI duration string. Valid formats: `30m`, `1h 30m`, `90 minutes`, `2 hours 30 minutes`, `1 day`, etc.
+
+- **`id_tokens:` `aud` validation (GL037)** — emits an `ERROR` for each OIDC token entry in `id_tokens:` that is missing the required `aud` key. GitLab returns an API error at pipeline start when `aud` is absent.
+
+- **`secrets:` provider validation (GL038)** — emits an `ERROR` for each secret entry in `secrets:` that does not declare a provider key (`vault`, `gcp_secret_manager`, or `azure_key_vault`).
+
+- **`pages:` keyword + `artifacts.paths` consistency (GL039)** — emits a `WARNING` when a job uses the `pages:` keyword but `artifacts.paths` does not include the publish directory (default `public`, or the value of `pages.publish`). GitLab Pages will not deploy unless the publish directory is listed as an artifact.
+
+- **Duplicate stage names (GL040)** — emits a `WARNING` when a stage name appears more than once in the top-level `stages:` list. GitLab silently merges duplicate stage entries, which can produce confusing pipeline ordering.
+
+- **`cache.key.files` glob detection (GL041)** — emits a `WARNING` when an entry in `cache.key.files` contains glob metacharacters (`*`, `?`, `[`). The `files` field requires exact file paths; GitLab does not expand globs there.
+
+## [0.2.15] - 2026-06-13
+
+### Added
+
+- **Static reachability check (GL033)** — warns when every rule in a job's `rules:` block has an explicit `when: never`, making the job permanently excluded from any pipeline run. This is a purely static claim: no matter which `if:` condition evaluates to true, the outcome is always "skip"; and if no rule matches, the implicit fallback is also skip. No expression evaluation or context is required. The finding is a `WARNING` (may be intentional as a "disabled job" pattern). Only jobs where every rule has the literal `when: never` value are flagged; rules with no `when:` (default `on_success`), `when: manual`, `when: always`, or `when: on_failure` are not.
+
+## [0.2.14] - 2026-06-13
+
+### Added
+
+- **`--version` / `-v` flag** — `glint --version`, `glint -v`, and `glint version` all print the compiled version string (e.g. `glint v0.2.14`). The version is also shown at the top of every `--help` output (global, `check --help`, `graph --help`). The version is injected at build time via `-ldflags "-X main.version=..."` using `git describe --tags --always --dirty`.
+
+- **Sorted findings output** — `Lint` now returns findings sorted by `(File, Line, Rule)`. All issues from the same source file appear together in ascending line order; pipeline-level findings with no file location sort first. Previously findings were emitted in map-iteration order (non-deterministic).
+
+### Fixed
+
+- **Warning format consistency** — include-resolution warnings, extends-chain warnings, and the workflow non-start warning now use the same ruff-style `path: [warning] message` format as lint findings instead of the old `[WARNING] …` prefix with no file context.
+
+- **Workflow rule permissive evaluation** — workflow `rules:if:` expressions are now evaluated in strict mode: an expression that cannot be fully parsed returns `false` (skip this rule, try the next) instead of `true` (match everything). Previously, a complex or partially-unsupported condition on the first workflow rule would match every context, blocking all subsequent rules and injecting the wrong variables. Job rules retain permissive evaluation (`true` on parse failure) to avoid silently dropping jobs.
+
+- **Single `=` operator in `rules:if:`** — a bare `=` not followed by `=` or `~` is now accepted as an alias for `==`. This is a common mistake in GitLab CI YAML; previously it caused a parse failure and triggered the permissive fallback.
+
+- **Source location lost through `extends:` resolution** — when a job was resolved via `extends:`, the merged definition was re-encoded and re-decoded as a fresh `model.Job` struct, which does not carry `File` or `Line` (they are not YAML keys). Those fields are now explicitly copied back from the original job before replacing it in `p.Jobs`, so extended jobs report the correct source file and line number in findings.
+
+## [0.2.13] - 2026-06-12
+
+### Added
+
+- **Variable expansion (`$VAR` / `${VAR}`)** — variable values that reference other variables are now expanded in the effective context after all sources are merged. Transitive chains (`A=$B`, `B=$C`) are resolved over up to ten passes; circular references are left as-is. The expanded values are visible in `--list-vars` output under "Effective context variables" and are used when evaluating `rules:if:` expressions.
+
+- **Non-string scalar variables (`bool`, `int`, `float64`)** — variables declared with bare `true`/`false` or integer values (e.g. `BUILD: true`, `RETRIES: 3`) are now handled correctly in all variable processing paths. Previously they were rendered as `(complex)` in `--list-vars` output and silently dropped from the effective context; they now render and inject as their string equivalents (`"true"`, `"3"`), matching GitLab CI's own behaviour where all variable values are strings.
+
+### Fixed
+
+- **YAML `\/` escape in double-quoted strings** — regex patterns containing `\/` (escaped forward-slash) in double-quoted `if:` expressions (e.g. `$CI_COMMIT_BRANCH =~ /^us\//`) caused a YAML parse error (`found unknown escape character`) with `gopkg.in/yaml.v3`, which does not implement this YAML 1.2 escape. The parser now preprocesses the raw bytes before unmarshalling: inside double-quoted strings, `\/` is rewritten to `\\/`, which `yaml.v3` parses as a literal backslash followed by a slash — preserving the regex intent.
+
+## [0.2.11] - 2026-06-12
+
+### Added
+
+- **Ruff-style finding output** — findings now follow the `file:line: RULEID [severity] message` format (e.g. `.gitlab-ci.yml:14: GL004 [error] job "deploy": stage "production" is not defined in 'stages'`), matching the output convention used by [ruff](https://docs.astral.sh/ruff/) and other modern linters. Job-scoped findings prefix the message with `job "name": `; pipeline-level findings omit the job prefix. Severity is lowercase inside brackets (`[error]`, `[warning]`).
+
+- **Implicit default context (`--branch main --source push`)** — when `glint check` or `glint graph` is invoked without any of `--branch`, `--tag`, `--source`, or `--var`, the context now defaults to `--branch main --source push` so that `rules:if:` expressions are always evaluated. Previously the context was empty and no rule evaluation occurred. Any explicit context flag bypasses the defaults entirely.
+
+- **`--list-vars` debug flag** — available on both `glint check` and `glint graph`; prints all pipeline-level variables collected from the root file and every included file (sorted `KEY=VALUE`) to stderr, then continues normally. When a context is active, also prints the effective merged variable set (pipeline defaults + workflow-rule variables + CLI flags). Useful for diagnosing GL032 false positives.
+
+- **Included-file variables now visible to all lint rules** — `variables:` blocks declared in included files (local, remote, project, and component includes) are now merged into the pipeline's variable namespace before linting. This eliminates false-positive GL032 warnings for variables declared in shared CI templates. Root-pipeline variables take precedence over included-file variables when the same key appears in both (matching GitLab's own override behaviour).
+
+- **Variable reference validation (GL032)** — glint now warns when a `rules:if:` expression references a variable (`$VAR` or `${VAR}`) that is not declared anywhere in the pipeline YAML: pipeline-level `variables:`, the job's own `variables:`, or any `workflow:rules:variables:` block. Predefined GitLab CI variable namespaces (`CI_*`, `GITLAB_*`, `FF_*`, `RUNNER_*`, `TRIGGER_*`, `CHAT_*`) are exempt. Because variables can also be set in GitLab CI/CD project settings (invisible to glint), the finding is a `[WARNING]` rather than an error. Each undeclared variable is reported at most once per job to keep the output concise.
+
+- **Structured rule IDs** — every finding now carries a stable `GL###` identifier (e.g. `GL003`) that appears in the output alongside the location and message: `.gitlab-ci.yml:14: GL003 [error] job "deploy": missing required field 'script'`. IDs are assigned per check function across 31 rules (GL001–GL031) and are stable across versions. The `linter.Finding` struct exposes the ID as a `Rule string` field for programmatic consumers. The README lint rules table is updated with ID columns.
+
+- **`workflow:rules:variables:` now propagate to job rule evaluation** — when a `workflow:rules:` entry matches, any `variables:` it defines are injected into the evaluation context so job `rules:if:` expressions can reference them. Pipeline-level `variables:` are also available as defaults (lower priority). Variable priority order, highest first: `--var` CLI overrides → `--branch`/`--tag`/`--source` shortcuts → workflow-rule variables → pipeline-level variable defaults. This means `$DEPLOY_TARGET == "production"` in a job rule correctly evaluates when a workflow rule sets `DEPLOY_TARGET: production` for the matching branch. The `glint graph tree` command benefits from the same enrichment.
+
+- **`rules:if:` expression evaluator improvements** — six correctness fixes to the GitLab CI expression parser:
+  - **Multi-line expressions** — newlines (`\n`, `\r`) are now treated as whitespace between tokens, so block-scalar `if:` values (e.g. `if: | ...`) and folded YAML scalars with `||`/`&&` on a continuation line are parsed correctly instead of falling back to permissive `true`.
+  - **`${VAR}` curly-brace variable syntax** — `${CI_COMMIT_BRANCH}` is now equivalent to `$CI_COMMIT_BRANCH` everywhere a value is expected.
+  - **Regex flags** — `/pattern/i`, `/pattern/m`, `/pattern/s` are now honoured; the `i` flag (case-insensitive) is translated to Go's `(?i)` prefix before compiling. Unknown flags are silently ignored.
+  - **Variable as regex RHS** — `$BRANCH =~ $PATTERN` where `$PATTERN` holds a `/regex/[flags]` string is now evaluated by extracting and compiling the pattern from the variable's value; if the value is empty or does not look like a regex literal the expression falls back to permissive `true`.
+  - **`true` / `false` keywords** — bare `true` and `false` (without quotes) are now recognised as the string values `"true"` and `"false"`, matching GitLab CI's own behaviour. `$GATEWAY_ENABLED == true` and `$FEATURE_FLAG == false` now evaluate correctly.
+  - **Integer literals** — bare integers (e.g. `$PARALLEL == 4`, `$ENABLED == 1`, `$DISABLED == 0`) are now parsed as their decimal string representations and compared accordingly.
+
 - **File and line numbers on findings** — every finding now includes the source file and line where the job is defined, e.g. `[ERROR] job "deploy" (src/deploy.yml:14): …`. For jobs that come from local or fetched includes the file reflects the include source. Pipeline-level findings (workflow rules, missing stages) reference the root pipeline file.
 
 - **`glint graph includes` shows jobs per file** — each node in the Mermaid include dependency graph now shows the jobs defined directly in that file. Jobs are rendered as rounded nodes (`(name)`) in a distinct light-purple style, connected with dashed arrows (`-.->`) to distinguish ownership from the include hierarchy (solid `-->` arrows). The root pipeline file always shows its direct jobs; local and fetched project/component nodes show theirs when the file can be read.

FEATURES.md

@@ -0,0 +1,259 @@
+# glint — feature reference
+
+This document describes every capability in the current release.
+For planned work see [ROADMAP.md](ROADMAP.md).
+
+---
+
+## Lint rules
+
+Every finding carries a stable rule ID (`GL001` – `GL043`) that can be used to
+suppress, filter, or look up the check. Run `glint explain <ID>` for a
+description, bad-YAML example, and fix.
+
+### Pipeline-level
+
+| ID | Sev | Rule |
+|----|-----|------|
+| GL001 | WARN | No `stages:` block — GitLab falls back to its built-in default stages |
+| GL002 | ERR | `workflow.rules[*].when` must be `always` or `never` |
+| GL036 | ERR | `default.timeout` is not a valid GitLab CI duration string |
+| GL040 | WARN | A stage name appears more than once in `stages:` |
+
+### Job structure
+
+| ID | Sev | Rule |
+|----|-----|------|
+| GL003 | ERR | Job missing required `script:` (or `run:`) |
+| GL004 | ERR | Job `stage:` references a stage not declared in `stages:` |
+| GL005 | ERR | `only:` and `rules:` used together |
+| GL006 | ERR | `except:` and `rules:` used together |
+| GL007 | WARN | `only:` / `except:` used (deprecated; prefer `rules:`) |
+
+### Keyword constraints
+
+| ID | Sev | Rule |
+|----|-----|------|
+| GL008 | ERR | `when:` has an invalid value |
+| GL009 | ERR | `when: delayed` without `start_in:` |
+| GL010 | ERR | `start_in:` set but `when:` is not `delayed` |
+| GL011 | ERR | `parallel:` integer not in range 2–200, or map form missing `matrix:` |
+| GL012 | ERR | `retry:` integer not in range 0–2, or `retry.max` out of range |
+| GL013 | ERR | `retry.when:` contains an unrecognised failure type |
+| GL014 | ERR | `allow_failure:` is not a boolean or a map with `exit_codes:` |
+| GL015 | ERR | `interruptible:` is not a boolean |
+| GL016 | ERR | Trigger job also defines `script:` |
+| GL017 | ERR | `trigger:` map missing `project:` or `include:` |
+| GL018 | ERR | `coverage:` is not a regex wrapped in `/…/` |
+| GL019 | ERR | `release:` missing required `tag_name:`, or is not a map |
+| GL020 | ERR | `environment.url` set without `environment.name`, or invalid `action:` |
+| GL021 | ERR | `artifacts.when` invalid, or `expose_as` set without `paths` |
+| GL022 | WARN | `pages` job `artifacts.paths` does not include `public/` |
+| GL023 | ERR | `cache.when` or `cache.policy` has an invalid value |
+| GL024 | ERR | `rules[*].when` has an invalid value |
+| GL025 | ERR | `image:` map form missing `name:` |
+| GL026 | ERR | `inherit.default` / `inherit.variables` is not a boolean or list |
+| GL034 | ERR | `services:` map form missing `name:`, or `alias:` is not a valid DNS label |
+| GL036 | ERR | `timeout:` is not a valid GitLab CI duration string |
+| GL037 | ERR | `id_tokens:` entry missing required `aud:` |
+| GL038 | ERR | `secrets:` entry missing a provider key (`vault`, `gcp_secret_manager`, `azure_key_vault`) |
+| GL039 | WARN | Job uses `pages:` keyword but `artifacts.paths` doesn't include the publish directory |
+| GL041 | WARN | `cache.key.files` entry looks like a glob; must be an exact file path |
+
+### Cross-job graph
+
+| ID | Sev | Rule |
+|----|-----|------|
+| GL027 | ERR/WARN | `needs:` references a job that doesn't exist (WARN when `optional: true`) |
+| GL028 | ERR | `needs:` references a job in a later stage |
+| GL029 | ERR | Circular dependency in `needs:` graph |
+| GL030 | ERR | `dependencies:` references a job that doesn't exist |
+| GL031 | ERR | `dependencies:` references a job in the same or a later stage |
+
+### Expression & reachability
+
+| ID | Sev | Rule |
+|----|-----|------|
+| GL032 | WARN | `rules:if:` references `$VAR` not declared in any `variables:` block (may be false-positive for project-setting variables) |
+| GL033 | WARN | Every rule in `rules:` has `when: never` — job permanently excluded (provable without evaluating `if:` expressions) |
+| GL035 | WARN | `rules:changes` / `rules:exists` path is absolute — absolute paths never match in GitLab CI |
+| GL042 | WARN | Every `rules:if:` condition evaluates to false given the declared variable values — job statically unreachable (only fires when all referenced variables are declared in YAML) |
+
+### Inheritance
+
+| ID | Sev | Rule |
+|----|-----|------|
+| GL043 | WARN | `inherit: default:` declared but the pipeline has no `default:` block (dead declaration), or the list form names fields not set in `default:` |
+
+### Hidden jobs
+
+Jobs whose name starts with `.` are reusable templates; most rules are skipped for them. This matches GitLab CI's own behaviour.
+
+---
+
+## Include resolution
+
+| Capability | Notes |
+|------------|-------|
+| `include: local:` | Read from disk, recursively merged before linting |
+| `include: remote:` | HTTPS URL fetched unauthenticated; unreachable URLs produce a warning, linting continues |
+| `include: project:` | Fetched from the GitLab REST API using the configured token; skipped with a warning when no token is available |
+| `include: component:` | Fetched from the GitLab CI/CD Catalog; public components work without a token |
+| `include: inputs:` | `$[[ inputs.KEY ]]` and `$[[ inputs.KEY \| default(…) ]]` placeholders substituted from the `with:` block before parsing |
+| Depth limit | Include chains capped at 100 levels (matches GitLab); circular cross-file references detected via visited-set tracking |
+| Offline mode | `--offline` serves all remote includes from the cache; missing entries produce a warning |
+| Include cache | `--cache-dir DIR` (or `~/.cache/glint` by default with `--offline`) persists fetched templates; keyed by SHA-256 of the request coordinates |
+
+**Token resolution order** (first non-empty wins):
+
+| Source | Header |
+|--------|--------|
+| `--token` flag / `GITLAB_TOKEN` env | `PRIVATE-TOKEN` |
+| `CI_JOB_TOKEN` env | `JOB-TOKEN` |
+| `GITLAB_PRIVATE_TOKEN` env | `PRIVATE-TOKEN` |
+
+**URL resolution order:** `--gitlab-url` flag → `CI_SERVER_URL` env → `GITLAB_URL` env → `https://gitlab.com`
+
+---
+
+## Context simulation
+
+Pass `--branch`, `--tag`, `--source`, or `--var` to evaluate `rules:if:` and
+`only`/`except` filters against a specific pipeline event. When no context flag
+is given glint defaults to `--branch main --source push` so that `rules:if:`
+expressions are always evaluated.
+
+**Evaluated at lint time:**
+
+- `rules:if:` — full expression language: `==`, `!=`, `=~`, `!~`, `&&`, `||`, `!`, `(…)`, `$VAR`/`${VAR}`, string literals, `null`, regex flags (`/pat/i`)
+- `only:` / `except:` — ref keywords, branch-name globs, and `/regex/` patterns
+- `workflow:rules:` — evaluated to determine whether the pipeline would run; matching rule's `variables:` are injected before job evaluation
+- Variable expansion — `$VAR` / `${VAR}` references in variable values expanded after all sources merge; transitive chains resolved (up to 10 passes)
+
+**Not evaluated** (no git tree at lint time): `rules:changes:`, `rules:exists:`.
+
+**Predefined variables** set by shortcut flags:
+
+| Flag | Variables populated |
+|------|---------------------|
+| `--branch NAME` | `CI_COMMIT_BRANCH`, `CI_COMMIT_REF_NAME`, `CI_COMMIT_REF_SLUG`, `CI_PIPELINE_SOURCE=push` |
+| `--tag NAME` | `CI_COMMIT_TAG`, `CI_COMMIT_REF_NAME`, `CI_COMMIT_REF_SLUG`, `CI_PIPELINE_SOURCE=push`; clears `CI_COMMIT_BRANCH` |
+| `--source EVENT` | `CI_PIPELINE_SOURCE` |
+| `--var KEY=VALUE` | any variable; overrides shortcuts; repeatable |
+
+Use `--list-vars` to print the resolved variable table to stderr.
+
+---
+
+## Output formats
+
+Pass `--format` to `glint check`. In structured formats the summary line is
+written to stderr so stdout contains only the machine-readable payload.
+
+| Format | Flag | Description |
+|--------|------|-------------|
+| Text (default) | `--format text` | Ruff-style `file:line: RULE [sev] message` |
+| JSON | `--format json` | Stable schema (version 1); `findings` array + `summary` block |
+| SARIF 2.1.0 | `--format sarif` | Consumed by GitHub Code Scanning and GitLab SAST |
+| JUnit XML | `--format junit` | CI test-report artifact (`artifacts:reports:junit`) |
+| GitHub annotations | `--format github` | `::error file=…,line=…,title=RULE::message` inline PR comments |
+
+**JSON schema (`schema_version: 1`):**
+```json
+{
+  "schema_version": 1,
+  "glint_version": "v0.2.20",
+  "pipeline": ".gitlab-ci.yml",
+  "findings": [
+    {"rule":"GL004","severity":"error","file":".gitlab-ci.yml","line":14,
+     "job":"deploy","message":"stage \"production\" is not defined in 'stages'"}
+  ],
+  "summary": {"total": 1, "errors": 1, "warnings": 0}
+}
+```
+
+---
+
+## Configuration
+
+### `.glint.yml` project config file
+
+Searched from the pipeline file's directory upward to the first `.git` boundary.
+
+```yaml
+# Suppress rules globally for this project.
+ignore:
+  - GL007   # migrating from only:/except:
+  - GL032   # dynamic variables injected by CI
+
+# Override rule severity (error | warning | ignore).
+# 'ignore' is equivalent to listing the rule in ignore:.
+severity:
+  GL004: warning   # demote during a stage migration
+  GL035: error     # promote to hard error for this project
+
+# Extra stage names valid beyond those in the pipeline's own stages: block.
+stages:
+  - quality
+  - security
+
+# Default GitLab token (lower priority than --token and GITLAB_TOKEN).
+token: glpat-xxxx
+
+# Default GitLab instance URL.
+url: https://gitlab.example.com
+
+# Default cache directory.
+cache_dir: ~/.cache/glint
+```
+
+**Priority chain:** `--token`/`--gitlab-url` flags > `.glint.yml` > environment variables.
+
+### Inline suppression (`# glint: ignore`)
+
+Suppress a finding for a specific job by placing a comment immediately before it:
+
+```yaml
+# glint: ignore GL007
+legacy-job:
+  only: [main]
+  script: echo ok
+
+# Multiple rules (comma- or space-separated):
+# glint: ignore GL007, GL032
+other-job:
+  script: echo ok
+
+# Suppress every rule for this job:
+# glint: ignore all
+noisy-job:
+  script: echo ok
+```
+
+Suppressions are scoped to the single job they precede and do not affect other
+jobs or pipeline-level findings.
+
+---
+
+## Graph visualization (`glint graph`)
+
+| Mode | Output |
+|------|--------|
+| `tree` (default) | Terminal job tree: stages as branches, jobs as leaves; annotated with `[manual]`, `[delayed]`, `[trigger]` where applicable |
+| `includes` | Mermaid flowchart to stdout; colour-coded nodes by include type (local, remote, project, component, template) |
+| `pipeline` | GitLab CI-style SVG/PNG written to `--out` directory (default: `glint-out/`); converted to PNG when `rsvg-convert`, `inkscape`, or `magick` is available |
+| `all` | `includes` to stdout + `pipeline` file path to stderr |
+
+In DAG pipelines (any job has `needs:`) the pipeline graph uses job-to-job
+Bézier connectors instead of stage-to-stage lines.
+
+---
+
+## Developer tools
+
+| Tool | Description |
+|------|-------------|
+| `glint explain <RULE>` | Print description, rationale, bad-YAML example, and fix for a rule. Case-insensitive (`gl007` = `GL007`). |
+| `glint explain` | List all rules with ID, severity, and title. |
+| `--list-vars` | Print all resolved pipeline variables (pipeline + workflow rules + context) to stderr before linting. |
+| `--version` / `-v` | Print the compiled version string. |

README.md

@@ -6,30 +6,23 @@
 
 <p align="center">
   <a href="LICENSE"><img src="https://img.shields.io/badge/license-Apache%202.0-blue.svg" alt="License"></a>
-  <a href="CHANGELOG.md"><img src="https://img.shields.io/badge/release-v0.2.0-blue.svg" alt="Release"></a>
+  <a href="CHANGELOG.md"><img src="https://img.shields.io/badge/release-v0.2.20-blue.svg" alt="Release"></a>
 </p>
 
 > **Disclaimer:** This tool was built through iterative AI-assisted development with [Claude](https://claude.ai). It is experimental, incomplete, and not intended for production use. Coverage of GitLab CI keywords is best-effort and may lag behind GitLab's evolving spec. Use it at your own discretion — no correctness guarantees are made. Contributions and bug reports are welcome.
 
 A local tool to validate and lint `.gitlab-ci.yml` pipelines without needing a GitLab server.
 
-## Features
+## What it does
 
-- **YAML validation** — detects malformed pipeline files early
-- **Stage validation** — every job's `stage` must be declared in `stages`
-- **`extends:` resolution** — resolves single and multi-level template inheritance before linting, so derived jobs are evaluated against their fully merged definition
-- **`needs:` DAG validation** — checks that `needs:` references exist, respect stage ordering, and contain no circular dependencies
-- **`dependencies:` validation** — checks that artifact dependency references exist and are in earlier stages
-- **Keyword validation** — validates constraints on `when`, `parallel`, `retry`, `allow_failure`, `trigger`, `artifacts`, `cache`, `release`, `environment`, `coverage`, `rules`, and more
-- **Remote project includes** — fetches `include: project:` templates from the GitLab API so extends/needs can be validated against the full merged pipeline
-- **CI/CD catalog components** — resolves `include: component:` references from the GitLab CI/CD Catalog; public components work without a token
-- **Deprecation warnings** — flags `only`/`except` usage in favour of `rules`
-- **Local include resolution** — `include: local:` entries are read from disk and recursively merged before linting, so multi-file pipelines are fully validated
-- **Extended variable declarations** — `variables:` entries may use the `{value, description, options}` map form (GitLab CI 13.7+); `default.image` accepts both string and map form; `rules.changes`/`rules.exists` accept both list and `{paths, compare_to}` map form
-- **Graph output** — `glint graph` prints a job tree (stages → jobs) to the terminal; `glint graph includes` emits a Mermaid include dependency diagram; `glint graph pipeline` renders a GitLab CI-style PNG/SVG
-- **Context simulation** — pass `--branch`, `--tag`, or `--source` to `glint check` or `glint graph` to see which jobs would be active, manual, or skipped for a specific pipeline event; evaluates `rules:if:` expressions and `only`/`except` filters
+- **Lints** — 43 rules covering pipeline structure, keyword constraints, `needs:`/`dependencies:` graphs, expression reachability, and deprecations (GL001–GL043); run `glint explain <ID>` for any rule
+- **Resolves includes** — local files, HTTPS URLs, GitLab project templates, and CI/CD Catalog components, with offline cache support
+- **Simulates context** — `--branch`, `--tag`, `--source` flags evaluate `rules:if:` and `only`/`except` to show which jobs would be active, manual, or skipped
+- **Multiple output formats** — `--format text` (default, ruff-style), `json`, `sarif` (GitHub Code Scanning / GitLab SAST), `junit`, `github` (PR annotations)
+- **Project config** — `.glint.yml` for rule suppression, severity overrides, token/URL defaults; `# glint: ignore RULE` for per-job inline suppression
+- **Graph visualization** — `glint graph` prints a terminal job tree; `glint graph pipeline` renders a GitLab CI-style SVG/PNG
 
-See [ROADMAP.md](ROADMAP.md) for planned improvements.
+See [FEATURES.md](FEATURES.md) for the complete feature reference and lint rules table, and [ROADMAP.md](ROADMAP.md) for planned improvements.
 
 ## Requirements
 
@@ -58,254 +51,12 @@ glint [OPTIONS] <COMMAND>
 Commands:
   check    Lint a pipeline file — exits 0 (clean) or 1 (errors found)
   graph    Visualise the pipeline as a job tree or Mermaid graph
+  explain  Print description and fix for a lint rule
 ```
 
-Run `glint <command> --help` for command-specific options and examples.
-
-### `glint check`
-
-```bash
-glint check .gitlab-ci.yml
-```
-
-Exits `0` when no errors are found, `1` when at least one error is reported.
-
-### Remote project includes
-
-Pipelines that include templates from other GitLab projects are supported.
-Provide a token so `glint` can fetch them:
-
-```bash
-# personal access token (read_api scope)
-GITLAB_TOKEN=glpat-xxxx glint check .gitlab-ci.yml
-
-# CI/CD job token (when running inside a pipeline)
-CI_JOB_TOKEN=$CI_JOB_TOKEN glint check .gitlab-ci.yml
-
-# self-hosted GitLab
-GITLAB_TOKEN=glpat-xxxx GITLAB_URL=https://gitlab.example.com glint check .gitlab-ci.yml
-
-# or via flags
-glint check --token glpat-xxxx --gitlab-url https://gitlab.example.com .gitlab-ci.yml
-```
-
-**Project includes** require a token; without one they are skipped with a
-warning and the rest of the pipeline is linted as-is.
-
-**Component includes** (`include: component: ...`) attempt the fetch
-unauthenticated, so public [CI/CD Catalog](https://gitlab.com/explore/catalog)
-components work without a token. A warning is emitted if the fetch fails.
-
-Token resolution order (first non-empty wins):
-
-| Source | Header used |
-|--------|-------------|
-| `--token` flag / `GITLAB_TOKEN` | `PRIVATE-TOKEN` |
-| `CI_JOB_TOKEN` | `JOB-TOKEN` |
-| `GITLAB_PRIVATE_TOKEN` | `PRIVATE-TOKEN` |
-
-Instance URL resolution order: `--gitlab-url` flag → `CI_SERVER_URL` →
-`GITLAB_URL` → `https://gitlab.com`
-
-### Component reference format
-
-```
-<host>/<project-path>/<component-name>@<version>
-
-gitlab.com/components/secret-detection/secret-detection@v0.1.0
-gitlab.com/my-org/ci-catalog/lint@main
-gitlab.example.com/platform/components/build@~latest
-```
-
-The component file is looked up in order:
-1. `templates/<component-name>.yml` (single-file layout)
-2. `templates/<component-name>/template.yml` (directory layout)
-
-Component input parameters (`with:`) are not validated — they are resolved by
-GitLab at runtime. Jobs in fetched components may use `$[[ inputs.xxx ]]`
-placeholders in fields like `stage`; `glint` skips those fields rather
-than producing false positive errors.
-
-### `glint graph`
-
-Visualise the pipeline. Without a mode word, prints a job tree and the include
-dependency graph separated by `---`.
-
-```bash
-# Default: job tree + include dependency graph
-glint graph .gitlab-ci.yml
-
-# Job tree only (stages → jobs, like the tree command)
-glint graph tree .gitlab-ci.yml
-
-# Include dependency graph → Mermaid flowchart to stdout
-glint graph includes .gitlab-ci.yml > includes.mmd
-
-# GitLab-like pipeline layout → PNG (or SVG fallback) written to --out dir
-glint graph pipeline .gitlab-ci.yml
-# prints the output file path, e.g.: glint-out/pipeline-20260607-143022.png
-
-# Mermaid to stdout + pipeline file path to stderr
-glint graph all .gitlab-ci.yml > includes.mmd
-
-# Custom output directory (pipeline mode)
-glint graph pipeline --out /tmp/graphs .gitlab-ci.yml
-```
-
-**Job tree** (`graph tree`) — stages as branches, jobs as leaves. Jobs with
-`when: manual`, `when: delayed`, or `trigger:` are annotated in brackets.
-
-**Include graph** (`graph includes`) — [Mermaid](https://mermaid.js.org) flowchart written to stdout.
-Pipe to a `.mmd` file or paste into [mermaid.live](https://mermaid.live).
-One node per include entry, colour-coded by type:
-- Orange (bold): the main pipeline file
-- Purple: `project:` includes
-- Green: `component:` includes
-- Blue: `local:` includes
-- Grey: `remote:` URL includes
-- Light orange: GitLab-provided `template:` includes
-
-**Pipeline graph** (`graph pipeline`) — GitLab CI-style SVG rendered to a timestamped file
-in the `--out` directory (default: `glint-out/`). Converted to PNG automatically
-when `rsvg-convert`, `inkscape`, or `magick` is available; falls back to SVG otherwise.
-Jobs are colour-coded by type:
-- Blue (`#1f75cb`): regular jobs
-- Orange (`#fc6d26`): `when: manual` jobs
-- Purple (`#6b4fbb`): `trigger:` jobs
-- Amber (`#fca326`): `when: delayed` jobs
-
-DAG mode (job-to-job Bézier arrows) activates automatically when any job has a `needs:` list.
-Classic mode draws L-shaped or straight connectors between stage columns otherwise.
-
-### Context simulation
-
-Pass `--branch`, `--tag`, or `--source` to `glint check` to see which jobs
-would run for a given pipeline event. The pipeline is still fully linted;
-context output is printed first.
-
-```bash
-# What runs on a push to develop?
-glint check --branch develop .gitlab-ci.yml
-
-# What runs when a v1.2.0 tag is pushed?
-glint check --tag v1.2.0 .gitlab-ci.yml
-
-# Merge request pipeline
-glint check --source merge_request_event .gitlab-ci.yml
-
-# Arbitrary variable overrides (repeatable)
-glint check --branch main --var DEPLOY_ENV=production .gitlab-ci.yml
-```
-
-**Evaluated:**
-- `rules:if:` — full expression language: `==`, `!=`, `=~`, `!~`, `&&`, `||`, `!`, `()`, `$VAR`, string literals, `null`
-- `only:` / `except:` — ref keywords (`branches`, `tags`, `merge_requests`, `schedules`, …), branch name globs (`feat/*`), and `/regex/` patterns
-
-**Not evaluated** (no git tree at lint time): `rules:changes:`, `rules:exists:`.
-Rules without an `if:` clause always match.
-
-**Predefined variables** set automatically by the shortcut flags:
-
-| Flag | Variables populated |
-|------|---------------------|
-| `--branch <name>` | `CI_COMMIT_BRANCH`, `CI_COMMIT_REF_NAME`, `CI_COMMIT_REF_SLUG`, `CI_PIPELINE_SOURCE=push` |
-| `--tag <name>` | `CI_COMMIT_TAG`, `CI_COMMIT_REF_NAME`, `CI_COMMIT_REF_SLUG`, `CI_PIPELINE_SOURCE=push` (clears `CI_COMMIT_BRANCH`) |
-| `--source <event>` | `CI_PIPELINE_SOURCE` |
-| `--var KEY=VALUE` | any variable; overrides shortcuts |
-
-### Example output
-
-```
-# Clean pipeline, no context
-OK: .gitlab-ci.yml — no issues found (5 jobs, 3 stages)
-
-# With --branch develop context
-Context: branch=develop, source=push
-
-Active  (3): build, deploy-staging, test
-Skipped (2): deploy-prod, release-notes
-
-OK: .gitlab-ci.yml — no issues found (5 jobs, 3 stages)
-
-# With --tag v1.0.0 context
-Context: tag=v1.0.0, source=push
-
-Active  (4): build, deploy-prod, release-notes, test
-Skipped (1): deploy-staging
-
-OK: .gitlab-ci.yml — no issues found (5 jobs, 3 stages)
-
-# Pipeline with issues
-[ERROR] job "deploy": stage "production" is not defined in 'stages'
-[ERROR] job "test": needs unknown job "build-app"
-[WARNING] job "old-job": 'only'/'except' are deprecated; prefer 'rules'
-
-3 finding(s): 2 error(s)
-```
-
-## Lint rules
-
-### Pipeline-level
-
-| Severity | Rule |
-|----------|------|
-| ERROR | `workflow.rules[*].when` is not `always` or `never` |
-| WARNING | No `stages` defined (GitLab falls back to default stages) |
-
-### Job-level — structure
-
-| Severity | Rule |
-|----------|------|
-| ERROR | Job is missing required `script` (or `run`) — non-trigger, non-template jobs |
-| ERROR | Job references a `stage` not declared in `stages` |
-| ERROR | `only` and `rules` used together on the same job |
-| ERROR | `except` and `rules` used together on the same job |
-| WARNING | `only`/`except` used (deprecated, prefer `rules`) |
-
-### Job-level — keyword constraints
-
-| Severity | Rule |
-|----------|------|
-| ERROR | `when` is not one of `on_success`, `on_failure`, `always`, `manual`, `delayed`, `never` |
-| ERROR | `when: delayed` without `start_in` |
-| ERROR | `start_in` set but `when` is not `delayed` |
-| ERROR | `parallel` integer not in range 2–200 |
-| ERROR | `parallel` map form missing `matrix` key |
-| ERROR | `retry` integer not in range 0–2 |
-| ERROR | `retry.max` not in range 0–2 |
-| ERROR | `retry.when` contains an invalid failure type |
-| ERROR | `allow_failure` is not a boolean or a map with `exit_codes` |
-| ERROR | `interruptible` is not a boolean |
-| ERROR | `trigger` job also has `script` |
-| ERROR | `trigger` map missing `project` or `include` |
-| ERROR | `coverage` is not a regex pattern wrapped in `/` |
-| ERROR | `release` missing required `tag_name` |
-| ERROR | `environment.url` set without `environment.name` |
-| ERROR | `environment.action` is not one of `start`, `stop`, `prepare`, `verify`, `access` |
-| ERROR | `artifacts.when` is not `on_success`, `on_failure`, or `always` |
-| ERROR | `artifacts.expose_as` set without `artifacts.paths` |
-| ERROR | `cache.when` is not `on_success`, `on_failure`, or `always` |
-| ERROR | `cache.policy` is not `pull`, `push`, or `pull-push` |
-| ERROR | `rules[*].when` is not one of the valid `when` values |
-| ERROR | `image` map form missing `name` key |
-| ERROR | `inherit.default` / `inherit.variables` is not a boolean or list |
-| WARNING | `pages` job `artifacts.paths` does not include `public` |
-
-### Cross-job graph
-
-| Severity | Rule |
-|----------|------|
-| ERROR | `needs:` references a job that does not exist |
-| ERROR | `needs:` references a job in a later stage |
-| ERROR | Circular dependency detected in `needs:` graph |
-| ERROR | `dependencies:` references a job that does not exist |
-| ERROR | `dependencies:` references a job in the same or a later stage |
-| WARNING | `extends:` references an unknown base job (resolver warning; extends chain skipped for that job) |
-| ERROR | Cycle detected in `extends:` graph |
-
-### Hidden jobs (templates)
-
-Jobs whose name starts with `.` are treated as reusable templates and skipped for most rules. This matches GitLab's own behaviour.
+Run `glint <command> --help` for all flags. See [USAGE.md](USAGE.md) for full
+examples covering output formats, context simulation, remote includes, cache,
+graph modes, and project configuration.
 
 ## Development
 

ROADMAP.md

@@ -4,26 +4,27 @@ This document tracks planned improvements to `glint`. Items are grouped by theme
 
 ---
 
-## Context-aware validation — ✓ single-context shipped in v0.2.0
+## Context simulation
 
-Single-context simulation is fully implemented. Pass `--branch`, `--tag`, `--source`, or `--var` to either `glint check` or `glint graph`; jobs are evaluated and shown as active / manual / skipped.
+Pass `--branch`, `--tag`, `--source`, or `--var` to `glint check` or `glint graph` to evaluate `rules:if:` expressions and `only`/`except` filters against a specific pipeline event.
 
-```bash
-# shipped: single-context simulation
-glint check --branch develop .gitlab-ci.yml
-glint check --tag v1.2.0 .gitlab-ci.yml
-glint check --source merge_request_event --var CI_MERGE_REQUEST_TARGET_BRANCH_NAME=main .gitlab-ci.yml
-glint graph tree --branch main .gitlab-ci.yml   # tree annotated with [skipped] / [manual]
-```
-
-**Remaining work**
-
-- **Multi-context simulation** — run multiple contexts in one invocation and print a comparison table:
-  ```bash
-  glint check --context branch=main --context branch=develop --context tag=v1.0.0 .gitlab-ci.yml
-  ```
+- ~~**Single-context simulation**~~ — ✓ shipped v0.2.0; `--branch`, `--tag`, `--source`, `--var` flags on both subcommands; jobs classified as active / manual / skipped
+- ~~**`workflow:rules:variables:` propagation**~~ — ✓ shipped post-v0.2.0; variables from the matching workflow rule entry injected into the evaluation context before job `rules:if:` expressions are evaluated
+- ~~**Expression evaluator: multi-line `if:` values**~~ — ✓ shipped post-v0.2.0; newlines in block-scalar and folded YAML `if:` values treated as whitespace
+- ~~**Expression evaluator: `${VAR}` syntax**~~ — ✓ shipped post-v0.2.0; `${CI_COMMIT_BRANCH}` equivalent to `$CI_COMMIT_BRANCH` everywhere
+- ~~**Expression evaluator: regex flags**~~ — ✓ shipped post-v0.2.0; `/pattern/i`, `/pattern/m`, `/pattern/s` supported
+- ~~**Expression evaluator: variable as regex RHS**~~ — ✓ shipped post-v0.2.0; `$BRANCH =~ $PATTERN` where `$PATTERN` holds a `/regex/` string evaluates correctly
+- ~~**Expression evaluator: bare `true`/`false` and integer literals**~~ — ✓ shipped post-v0.2.0; `$FLAG == true`, `$COUNT == 4` compare as decimal strings matching GitLab CI behaviour
+- ~~**Implicit default context**~~ — ✓ shipped v0.2.11; defaults to `--branch main --source push` when no context flag is given, so `rules:if:` is always evaluated
+- ~~**`--list-vars` debug flag**~~ — ✓ shipped v0.2.11; prints sorted `KEY=VALUE` of all collected pipeline variables (root file + includes + workflow-rule union + effective context) to stderr
+- ~~**Variable expansion**~~ — ✓ shipped v0.2.13; `$VAR`/`${VAR}` references within variable values expanded after all sources are merged; transitive chains resolved; visible in `--list-vars`
+- ~~**Non-string scalar variables**~~ — ✓ shipped v0.2.13; `BUILD: true`, `RETRIES: 3` rendered and injected correctly instead of being silently dropped
+- ~~**YAML `\/` escape in double-quoted strings**~~ — ✓ shipped v0.2.13; regex patterns like `/^us\//` in double-quoted `if:` blocks no longer cause a parse error
+- ~~**Workflow rule strict evaluation**~~ — ✓ shipped v0.2.14; unparseable `if:` skips the rule instead of matching everything; prevents wrong variables being injected
+- ~~**Single `=` operator**~~ — ✓ shipped v0.2.14; bare `=` accepted as alias for `==` in `rules:if:` expressions
+- **Multi-context simulation** — run multiple contexts in one invocation and print a comparison table (`--context branch=main --context branch=develop --context tag=v1.0.0`)
 - **Context-scoped linting** — skip `needs:`/`dependencies:` cross-checks for jobs that are statically unreachable in the given context
-- **`rules:changes:` evaluation** — path glob evaluation against the local git tree (expression evaluator priority 5)
+- **`rules:changes:` evaluation** — path glob evaluation against the local git tree
 
 ---
 
@@ -31,37 +32,36 @@ glint graph tree --branch main .gitlab-ci.yml   # tree annotated with [skipped]
 
 The current rule set covers the most common sources of broken pipelines. These are the gaps most likely to matter in practice.
 
-- **Variable reference validation** — warn when a job references `$VAR` (or `${VAR}`) that is not declared anywhere in `variables:`, `default.variables`, or the job itself
-- **`services:` validation** — map form requires `name`; `alias` must be a valid DNS label
-- **`rules:changes` / `rules:exists`** — warn on glob patterns that can never match (e.g. absolute paths, double `**` on unsupported versions)
-- **`timeout` format** — must be a duration string GitLab understands (`1h 30m`, `90 minutes`, etc.)
-- **`id_tokens:` / `secrets:`** — presence and required-key checks
-- **`pages:publish`** — validate that the path is consistent with `artifacts.paths`
-- **`inherit:` completeness** — flag when a job overrides a default field that would require `inherit: default: false` to suppress
-- **Unreachable jobs** — detect jobs that can never run because every `rules:` branch evaluates to `never` (static analysis only, no variable expansion)
-- **Duplicate stage names** — GitLab silently merges them; warn to avoid confusion
-- **`cache:key:files`** — must be a list of paths, not a glob
+- ~~**Variable reference validation (GL032)**~~ — ✓ shipped v0.2.11; warns when a `rules:if:` expression references `$VAR` / `${VAR}` not declared anywhere in pipeline YAML; predefined GitLab namespaces (`CI_*`, `GITLAB_*`, …) exempt; variables from included files are also considered
+- ~~**`rules:if:` static reachability (GL033)**~~ — ✓ shipped v0.2.15; warns when every rule in a job's `rules:` block has `when: never`, making the job permanently excluded from any pipeline run; no `if:` evaluation required
+- ~~**`services:` validation (GL034)**~~ — ✓ shipped v0.2.16; map form requires `name`; `alias` must be a valid DNS label
+- ~~**`rules:changes` / `rules:exists` absolute path detection (GL035)**~~ — ✓ shipped v0.2.16; warns when a path starts with `/`; GitLab CI paths are always relative to the repo root
+- ~~**`timeout` format validation (GL036)**~~ — ✓ shipped v0.2.16; validates job-level and `default.timeout` against recognised GitLab CI duration strings
+- ~~**`id_tokens:` / `secrets:` required-key checks (GL037, GL038)**~~ — ✓ shipped v0.2.16; `id_tokens` entries must have `aud`; `secrets` entries must declare a provider
+- ~~**`pages:publish` + `artifacts.paths` consistency (GL039)**~~ — ✓ shipped v0.2.16; warns when the publish directory is missing from `artifacts.paths`
+- ~~**Duplicate stage names (GL040)**~~ — ✓ shipped v0.2.16; warns when a stage appears more than once in `stages:`
+- ~~**`cache:key:files` must be exact paths (GL041)**~~ — ✓ shipped v0.2.16; warns when entries look like glob patterns
+- ~~**Unreachable jobs**~~ — covered by GL033 (shipped v0.2.15); every-`when:never` rules block is statically dead
+- ~~**`inherit:` completeness (GL043)**~~ — ✓ shipped v0.2.20; warns when `inherit: default:` is declared but there's no `default:` block, or list form names fields not set in `default:`
 
 ---
 
 ## Include resolution
 
 - ~~**`include: local:`** full resolution~~ — ✓ shipped in v0.2.0; local files are read from disk, recursively resolved, and merged before linting
-- **`include: remote:`** (URL) — fetch and merge plain HTTP/HTTPS URLs (no auth required)
-- **Recursive include depth limit** — guard against include cycles across files
-- **Offline mode / cache** — persist fetched remote templates to a local cache directory; `--offline` flag to skip network calls and use only cached copies
-- **`include: inputs:`** — substitute CI component input values into fetched templates before merging, so component-scoped jobs get their correct `stage:` and keyword values
+- ~~**`include: remote:`** (URL)~~ — ✓ shipped post-v0.2.0; plain HTTPS URLs are fetched (unauthenticated), parsed, and merged; sub-includes are resolved recursively; unreachable URLs emit `[WARNING]` and linting continues
+- ~~**Recursive include depth limit**~~ — ✓ shipped v0.2.17; depth capped at 100 (matching GitLab); project/component includes now tracked in visited set to prevent cross-file cycles
+- ~~**Offline mode / cache**~~ — ✓ shipped v0.2.17; `--cache-dir DIR` persists fetched templates; `--offline` serves from cache only; default cache dir (`~/.cache/glint`) used automatically with `--offline`
+- ~~**`include: inputs:`**~~ — ✓ shipped v0.2.17; `$[[ inputs.KEY ]]` and `$[[ inputs.KEY | default(…) ]]` placeholders in fetched component YAML are substituted from the include's `with:` block before parsing
 
 ---
 
-## Output formats
+## Output formats — ✓ shipped v0.2.18
 
-Right now the only output is plain-text findings. Structured output enables integration with other tools.
-
-- **JSON** (`--format json`) — machine-readable findings with file, job, severity, rule ID, and message; stable schema
-- **SARIF** (`--format sarif`) — [Static Analysis Results Interchange Format](https://sarifweb.azurewebsites.net); consumed natively by GitHub Code Scanning and GitLab SAST
-- **JUnit XML** (`--format junit`) — lets CI pipelines publish lint results as a test report artifact
-- **GitHub / GitLab annotation format** — emit `::error file=…,line=…::message` lines so findings appear as inline comments in PR diffs
+- ~~**JSON** (`--format json`)~~ — ✓ shipped v0.2.18; machine-readable findings with stable schema (version 1)
+- ~~**SARIF** (`--format sarif`)~~ — ✓ shipped v0.2.18; SARIF 2.1.0; consumed natively by GitHub Code Scanning and GitLab SAST
+- ~~**JUnit XML** (`--format junit`)~~ — ✓ shipped v0.2.18; lets CI pipelines publish lint results as a test report artifact
+- ~~**GitHub annotation format** (`--format github`)~~ — ✓ shipped v0.2.18; emits `::error file=…,line=…,title=RULE::message` lines so findings appear as inline comments in PR diffs
 
 ---
 
@@ -70,6 +70,7 @@ Right now the only output is plain-text findings. Structured output enables inte
 The SVG renderer and terminal tree cover the basic layout. These would bring it closer to GitLab's full interactive view.
 
 - ~~**Terminal job tree**~~ — ✓ shipped in v0.2.0 as `glint graph tree`; stages as branches, jobs as leaves, context-aware annotations
+- ~~**`glint graph includes` shows jobs per file**~~ — ✓ shipped post-v0.2.0; each include node shows the jobs it defines as dashed-arrow rounded nodes in a distinct style
 - **Multi-job connector accuracy** — draw one connector per job pair rather than one per stage pair in classic mode, so pipelines with uneven columns look correct
 - **Job tooltip / detail panel** — embed a hidden `<title>` and `<desc>` per chip so SVG viewers show `stage`, `when`, `image`, and `needs` on hover
 - **`when: on_failure` visual distinction** — dashed border or distinct icon for failure-path jobs
@@ -79,6 +80,20 @@ The SVG renderer and terminal tree cover the basic layout. These would bring it
 
 ---
 
+## Findings quality — ✓ file and line numbers shipped post-v0.2.0; ruff-style format shipped v0.2.11
+
+~~**File and line numbers on findings**~~ — ✓ shipped post-v0.2.0; every finding includes the source file and exact line of the job key. Works across local includes, remote project templates, and fetched component templates.
+
+~~**Ruff-style output format**~~ — ✓ shipped v0.2.11; findings follow `file:line: RULEID [severity] message` matching the convention used by ruff and other modern linters.
+
+**Remaining improvements**
+
+- ~~**`needs: optional: true` false-positive errors**~~ — ✓ shipped post-v0.2.0; optional missing needs are downgraded to `[WARNING]`
+- ~~**`extends:` jobs with missing script false errors**~~ — ✓ shipped post-v0.2.0; jobs using `extends:` that have no `script` after resolution emit `[WARNING]` (the script may come from an unfetchable remote base)
+- ~~**`rules:if:` static reachability (GL042)**~~ — ✓ shipped v0.2.20; warns when all `rules:if:` conditions evaluate to false given declared variable values (only fires when all referenced vars are declared in YAML)
+
+---
+
 ## CI / editor integration
 
 - **GitLab CI template** — a `.gitlab-ci.yml` snippet that runs `glint` as a pipeline-validation job before the real pipeline executes; publishable to the GitLab CI/CD Catalog
@@ -89,21 +104,17 @@ The SVG renderer and terminal tree cover the basic layout. These would bring it
 
 ---
 
-## Configuration
+## Configuration — ✓ shipped v0.2.19
 
-- **`.glint.yml` config file** — project-level configuration for:
-  - Rule suppression by rule ID (e.g. `ignore: [no-only, missing-stages]`)
-  - Severity overrides (demote specific errors to warnings)
-  - Custom `stages` allowlist for projects that use a non-standard default set
-  - Token and URL defaults so flags are not needed in every invocation
-- **Inline suppression comments** — `# glint: ignore next-line <rule-id>` in the pipeline YAML
+- ~~**`.glint.yml` config file**~~ — ✓ shipped v0.2.19; `ignore:`, `severity:`, `stages:`, `token:`, `url:`, `cache_dir:`; searched from the pipeline directory up to the git root
+- ~~**Inline suppression comments**~~ — ✓ shipped v0.2.19; `# glint: ignore GL007` before a job definition; comma/space-separated rules; `# glint: ignore all` wildcard
 
 ---
 
 ## Reliability and developer experience
 
-- **Structured rule IDs** — assign a stable short ID to every rule (e.g. `GS001`) so suppression, documentation, and SARIF output are stable across versions
-- **`--explain <rule-id>`** — print the rule description, rationale, and an example fix
+- ~~**Structured rule IDs**~~ — ✓ shipped post-v0.2.0; GL001–GL031 assigned; GL032 added v0.2.11; GL033 added v0.2.15; GL034–GL041 added v0.2.16; output formats (--format json/sarif/junit/github) added v0.2.18; GL042–GL043 added v0.2.20
+- ~~**`glint explain <rule-id>`**~~ — ✓ shipped v0.2.20; prints rule description, rationale, bad-YAML example, and fix; `glint explain` (no arg) lists all rules
 - ~~**Semantic versioning and first release**~~ — shipped as `v0.1.0` (2026-06-07)
 - ~~**Subcommand CLI**~~ — shipped as `v0.2.0` (2026-06-11); `glint check` / `glint graph [mode]` with ruff-style `--help`
 - **Changelog automation** — generate release notes from Conventional Commits via `git-cliff` or similar

Taskfile.yml

@@ -3,6 +3,8 @@ version: "3"
 vars:
   BINARY: glint
   GO: /usr/local/go/bin/go
+  VERSION:
+    sh: git describe --tags --always --dirty 2>/dev/null || echo "dev"
 
 tasks:
   default:
@@ -12,7 +14,7 @@ tasks:
   build:
     desc: Build the glint binary
     cmds:
-      - "{{.GO}} build -o {{.BINARY}} ./cmd/glint/..."
+      - "{{.GO}} build -ldflags \"-X main.version={{.VERSION}}\" -o {{.BINARY}} ./cmd/glint/..."
     sources:
       - "**/*.go"
       - go.mod
@@ -59,21 +61,78 @@ tasks:
         ignore_error: false
       - cmd: ./{{.BINARY}} check --tag v1.0.0 testdata/context_rules.yml
         ignore_error: false
-      - cmd: ./{{.BINARY}} check samba-testdata/.gitlab-ci.yml
+      - cmd: ./{{.BINARY}} check testdata/rules_if_expr.yml
         ignore_error: false
-      - cmd: ./{{.BINARY}} check samba-testdata/.gitlab-ci-coverage.yml
+      - cmd: ./{{.BINARY}} check --branch main testdata/rules_if_expr.yml
         ignore_error: false
-      - cmd: ./{{.BINARY}} check samba-testdata/.gitlab-ci-private.yml
+      - cmd: ./{{.BINARY}} check --branch feat/x testdata/rules_if_expr.yml
+        ignore_error: false
+      - cmd: ./{{.BINARY}} check testdata/workflow_vars.yml
+        ignore_error: false
+      - cmd: ./{{.BINARY}} check --branch main testdata/workflow_vars.yml
+        ignore_error: false
+      - cmd: ./{{.BINARY}} check --branch develop testdata/workflow_vars.yml
+        ignore_error: false
+      - cmd: ./{{.BINARY}} check --branch feat/x testdata/workflow_vars.yml
+        ignore_error: false
+      - cmd: ./{{.BINARY}} check testdata/workflow_escape.yml
+        ignore_error: false
+      - cmd: ./{{.BINARY}} check testdata/variable_refs.yml
+        ignore_error: false
+      - cmd: ./{{.BINARY}} check testdata/variable_refs_included.yml
+        ignore_error: false
+      - cmd: ./{{.BINARY}} check testdata/dead_rules.yml
+        ignore_error: false
+      - cmd: ./{{.BINARY}} check testdata/new_rules_valid.yml
+        ignore_error: false
+      - cmd: ./{{.BINARY}} check testdata/new_rules_invalid.yml
+        ignore_error: true
+      - cmd: ./{{.BINARY}} check testdata/samba/.gitlab-ci.yml
+        ignore_error: false
+      - cmd: ./{{.BINARY}} check testdata/samba/.gitlab-ci-coverage.yml
+        ignore_error: false
+      - cmd: ./{{.BINARY}} check testdata/samba/.gitlab-ci-private.yml
+        ignore_error: false
+      - cmd: ./{{.BINARY}} check --format json testdata/valid.yml
+        ignore_error: false
+      - cmd: ./{{.BINARY}} check --format sarif testdata/valid.yml
+        ignore_error: false
+      - cmd: ./{{.BINARY}} check --format junit testdata/valid.yml
+        ignore_error: false
+      - cmd: ./{{.BINARY}} check --format github testdata/invalid.yml
+        ignore_error: true
+      - cmd: ./{{.BINARY}} check testdata/config_ignored/.gitlab-ci.yml
+        ignore_error: false
+      - cmd: ./{{.BINARY}} check testdata/config_severity/.gitlab-ci.yml
+        ignore_error: false
+      - cmd: ./{{.BINARY}} check testdata/config_suppress/.gitlab-ci.yml
+        ignore_error: false
+      - cmd: ./{{.BINARY}} check testdata/static_dead_rules.yml
+        ignore_error: false
+      - cmd: ./{{.BINARY}} check testdata/inherit_dead.yml
+        ignore_error: false
+      - cmd: ./{{.BINARY}} check testdata/inherit_dead_fields.yml
+        ignore_error: false
+      - cmd: ./{{.BINARY}} explain GL007
+        ignore_error: false
+      - cmd: ./{{.BINARY}} explain gl042
+        ignore_error: false
+      - cmd: ./{{.BINARY}} explain
         ignore_error: false
 
   lint-go:
     desc: Run go vet on all packages
     cmd: "{{.GO}} vet ./..."
 
+  lint-static:
+    desc: Run staticcheck on all packages
+    cmd: "{{.GO}} tool staticcheck ./..."
+
   ci:
-    desc: Full CI check — vet, test, build, validate
+    desc: Full CI check — vet, staticcheck, test, build, validate
     cmds:
       - task: lint-go
+      - task: lint-static
       - task: test
       - task: build
       - task: validate
@@ -87,7 +146,7 @@ tasks:
       - sh: git describe --tags --exact-match
         msg: "Current commit is not tagged — Windows build requires a git tag"
     cmds:
-      - "GOOS=windows GOARCH=amd64 {{.GO}} build -o {{.BINARY}}-{{.TAG}}.exe ./cmd/glint/..."
+      - "GOOS=windows GOARCH=amd64 {{.GO}} build -ldflags \"-X main.version={{.TAG}}\" -o {{.BINARY}}-{{.TAG}}.exe ./cmd/glint/..."
     sources:
       - "**/*.go"
       - go.mod
@@ -103,7 +162,7 @@ tasks:
       - sh: git describe --tags --exact-match
         msg: "Current commit is not tagged — Linux build requires a git tag"
     cmds:
-      - "GOOS=linux GOARCH=amd64 {{.GO}} build -o {{.BINARY}}-{{.TAG}}-linux-amd64 ./cmd/glint/..."
+      - "GOOS=linux GOARCH=amd64 {{.GO}} build -ldflags \"-X main.version={{.TAG}}\" -o {{.BINARY}}-{{.TAG}}-linux-amd64 ./cmd/glint/..."
     sources:
       - "**/*.go"
       - go.mod

USAGE.md

@@ -0,0 +1,314 @@
+# glint — usage reference
+
+Full examples and option descriptions for every command.
+For the lint rules reference see [FEATURES.md](FEATURES.md).
+
+---
+
+## `glint check`
+
+Lint a pipeline file. Exits `0` when no errors are found, `1` when at least
+one error is reported (warnings alone do not fail).
+
+```bash
+glint check .gitlab-ci.yml
+```
+
+### Output formats
+
+Pass `--format` to control the output. Plain text is the default.
+
+```bash
+# Default: ruff-style text (human-readable)
+glint check .gitlab-ci.yml
+
+# JSON — stable schema, machine-readable
+glint check --format json .gitlab-ci.yml
+
+# SARIF 2.1.0 — GitHub Code Scanning / GitLab SAST
+glint check --format sarif .gitlab-ci.yml > glint.sarif
+
+# JUnit XML — CI test-report artifact (GitLab: artifacts:reports:junit)
+glint check --format junit .gitlab-ci.yml > glint-junit.xml
+
+# GitHub Actions annotations — inline PR diff comments
+glint check --format github .gitlab-ci.yml
+```
+
+In structured formats (`json`, `sarif`, `junit`, `github`) the summary line is
+written to stderr so stdout contains only the machine-readable payload.
+
+**JSON schema (`schema_version: 1`):**
+```json
+{
+  "schema_version": 1,
+  "glint_version": "v0.2.20",
+  "pipeline": ".gitlab-ci.yml",
+  "findings": [
+    {"rule":"GL004","severity":"error","file":".gitlab-ci.yml","line":14,
+     "job":"deploy","message":"stage \"production\" is not defined in 'stages'"}
+  ],
+  "summary": {"total": 1, "errors": 1, "warnings": 0}
+}
+```
+
+**GitHub annotation lines:**
+```
+::error file=.gitlab-ci.yml,line=14,title=GL004::job "deploy": stage "production" is not defined in 'stages'
+```
+
+### Context simulation
+
+Pass `--branch`, `--tag`, or `--source` to evaluate `rules:if:` and
+`only`/`except` against a specific pipeline event. The pipeline is still fully
+linted; the context summary is printed first. When no context flag is given,
+glint defaults to `--branch main --source push`.
+
+```bash
+# What runs on a push to develop?
+glint check --branch develop .gitlab-ci.yml
+
+# What runs when a v1.2.0 tag is pushed?
+glint check --tag v1.2.0 .gitlab-ci.yml
+
+# Merge request pipeline
+glint check --source merge_request_event .gitlab-ci.yml
+
+# Arbitrary variable overrides (repeatable)
+glint check --branch main --var DEPLOY_ENV=production .gitlab-ci.yml
+
+# Debug variable resolution
+glint check --list-vars .gitlab-ci.yml
+```
+
+**Predefined variables** set by the shortcut flags:
+
+| Flag | Variables populated |
+|------|---------------------|
+| `--branch NAME` | `CI_COMMIT_BRANCH`, `CI_COMMIT_REF_NAME`, `CI_COMMIT_REF_SLUG`, `CI_PIPELINE_SOURCE=push` |
+| `--tag NAME` | `CI_COMMIT_TAG`, `CI_COMMIT_REF_NAME`, `CI_COMMIT_REF_SLUG`, `CI_PIPELINE_SOURCE=push`; clears `CI_COMMIT_BRANCH` |
+| `--source EVENT` | `CI_PIPELINE_SOURCE` |
+| `--var KEY=VALUE` | any variable; overrides shortcuts; repeatable |
+
+### Remote project includes
+
+Provide a token so glint can fetch `include: project:` templates:
+
+```bash
+# Personal access token (read_api scope)
+GITLAB_TOKEN=glpat-xxxx glint check .gitlab-ci.yml
+
+# CI/CD job token (when running inside a pipeline)
+CI_JOB_TOKEN=$CI_JOB_TOKEN glint check .gitlab-ci.yml
+
+# Self-hosted GitLab
+GITLAB_TOKEN=glpat-xxxx GITLAB_URL=https://gitlab.example.com glint check .gitlab-ci.yml
+
+# Via flags (override env vars)
+glint check --token glpat-xxxx --gitlab-url https://gitlab.example.com .gitlab-ci.yml
+```
+
+Project includes are skipped with a warning when no token is available; linting
+continues with whatever is resolved.
+
+**Token resolution order** (first non-empty wins):
+
+| Source | Header |
+|--------|--------|
+| `--token` flag / `GITLAB_TOKEN` env | `PRIVATE-TOKEN` |
+| `CI_JOB_TOKEN` env | `JOB-TOKEN` |
+| `GITLAB_PRIVATE_TOKEN` env | `PRIVATE-TOKEN` |
+
+**URL resolution order:** `--gitlab-url` flag → `CI_SERVER_URL` env → `GITLAB_URL` env → `https://gitlab.com`
+
+### Include cache and offline mode
+
+```bash
+# Cache fetched templates to disk (keyed by SHA-256 of the request coordinates)
+glint check --cache-dir ~/.cache/glint .gitlab-ci.yml
+
+# Fully offline — serve from cache, warn on misses, make no network calls
+glint check --offline .gitlab-ci.yml
+glint check --offline --cache-dir /path/to/cache .gitlab-ci.yml
+```
+
+`--offline` without `--cache-dir` uses `~/.cache/glint` automatically.
+There is no automatic cache expiry; delete the directory or individual entries
+to force a re-fetch.
+
+### Component reference format
+
+`include: component:` references follow the format:
+
+```
+<host>/<project-path>/<component-name>@<version>
+
+gitlab.com/components/secret-detection/secret-detection@v0.1.0
+gitlab.com/my-org/ci-catalog/lint@main
+gitlab.example.com/platform/components/build@~latest
+```
+
+The component file is looked up in order:
+1. `templates/<component-name>.yml` (single-file layout)
+2. `templates/<component-name>/template.yml` (directory layout)
+
+Public Catalog components work without a token. `with:` input parameters are
+substituted locally before parsing; they are not validated against the
+component spec.
+
+### Example output
+
+```
+# Clean pipeline
+Context: branch=main, source=push
+
+Active  (5): build, deploy-staging, test, lint, security-scan
+
+OK: .gitlab-ci.yml — no issues found (5 job(s), 3 stage(s))
+
+# With --branch develop
+Context: branch=develop, source=push
+
+Active  (3): build, deploy-staging, test
+Skipped (2): deploy-prod, release-notes
+
+OK: .gitlab-ci.yml — no issues found (5 job(s), 3 stage(s))
+
+# Pipeline with issues
+.gitlab-ci.yml:14: GL004 [error] job "deploy": stage "production" is not defined in 'stages'
+.gitlab-ci.yml:22: GL027 [error] job "test": needs unknown job "build-app"
+.gitlab-ci.yml:31: GL007 [warning] job "old-job": 'only'/'except' are deprecated; prefer 'rules'
+
+3 finding(s): 2 error(s)
+```
+
+---
+
+## `glint graph`
+
+Visualise the pipeline. Without a mode word, prints a job tree and the include
+dependency graph separated by `---`.
+
+```bash
+# Default: job tree + include dependency graph
+glint graph .gitlab-ci.yml
+
+# Job tree only
+glint graph tree .gitlab-ci.yml
+
+# Job tree with context (shows active/manual/skipped annotations)
+glint graph tree --branch develop .gitlab-ci.yml
+
+# Include dependency graph → Mermaid flowchart to stdout
+glint graph includes .gitlab-ci.yml > includes.mmd
+
+# GitLab-like pipeline layout → PNG/SVG written to --out dir
+glint graph pipeline .gitlab-ci.yml
+# prints the output path, e.g.: glint-out/pipeline-20260614-143022.png
+
+# Mermaid to stdout + pipeline file path to stderr
+glint graph all .gitlab-ci.yml > includes.mmd
+
+# Custom output directory
+glint graph pipeline --out /tmp/graphs .gitlab-ci.yml
+```
+
+**Job tree** — stages as branches, jobs as leaves; annotated with `[manual]`,
+`[delayed]`, `[trigger]` where applicable. Context flags apply the same
+evaluation as `glint check`.
+
+**Include graph** — [Mermaid](https://mermaid.js.org) flowchart; pipe to `.mmd`
+or paste into [mermaid.live](https://mermaid.live). Nodes are colour-coded by
+include type: orange (main file), purple (project), green (component), blue
+(local), grey (remote URL), light orange (GitLab template).
+
+**Pipeline graph** — GitLab CI-style SVG rendered to a timestamped file.
+Converted to PNG when `rsvg-convert`, `inkscape`, or `magick` is available.
+DAG mode (Bézier arrows between jobs) activates automatically when any job has
+a `needs:` list; classic mode uses stage-column connectors otherwise.
+
+---
+
+## `glint explain`
+
+Print the documentation for a specific lint rule.
+
+```bash
+# Description, example, and fix for GL007
+glint explain GL007
+
+# Case-insensitive
+glint explain gl007
+
+# List all rules with ID, severity, and title
+glint explain
+```
+
+---
+
+## Project configuration (`.glint.yml`)
+
+Place a `.glint.yml` anywhere in the directory tree from the pipeline file up
+to the first `.git` boundary. glint searches upward and uses the first file it
+finds.
+
+```yaml
+# Suppress rules globally for this project.
+ignore:
+  - GL007   # migrating from only:/except:
+  - GL032   # dynamic variables injected by CI
+
+# Override rule severity: error | warning | ignore
+# 'ignore' is equivalent to listing the rule under ignore:.
+severity:
+  GL004: warning   # demote during a stage migration
+  GL035: error     # promote to hard error for this project
+
+# Extra stage names valid beyond those declared in the pipeline YAML
+# (e.g. injected by an include template you don't own).
+stages:
+  - quality
+  - security
+
+# Default token — lower priority than --token and GITLAB_TOKEN.
+token: glpat-xxxx
+
+# Default GitLab instance URL.
+url: https://gitlab.example.com
+
+# Default cache directory for fetched remote includes.
+cache_dir: ~/.cache/glint
+```
+
+**Priority chain:** `--token`/`--gitlab-url` flags > `.glint.yml` > environment variables.
+
+---
+
+## Inline suppression (`# glint: ignore`)
+
+Suppress a finding for a specific job by placing a comment immediately before
+the job definition in the pipeline YAML:
+
+```yaml
+# glint: ignore GL007
+legacy-job:
+  stage: build
+  only: [main]
+  script: echo ok
+
+# Multiple rules — comma- or space-separated:
+# glint: ignore GL007, GL032
+other-job:
+  stage: build
+  script: echo ok
+
+# Suppress every rule for this job:
+# glint: ignore all
+noisy-job:
+  stage: build
+  script: echo ok
+```
+
+Suppressions are scoped to the single job they precede and do not affect other
+jobs or pipeline-level findings. For project-wide suppression, use `.glint.yml`
+`ignore:` instead.

cmd/glint/explain.go

@@ -0,0 +1,69 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"sort"
+	"strings"
+
+	"git.k3nny.fr/glint/internal/linter"
+)
+
+func cmdExplain(args []string) {
+	if len(args) == 0 {
+		printRuleList()
+		return
+	}
+	ruleID := strings.ToUpper(args[0])
+	entry, ok := linter.RuleCatalog[ruleID]
+	if !ok {
+		fmt.Fprintf(os.Stderr, "glint explain: unknown rule %q\n\nRun 'glint explain' to list all rules.\n", ruleID)
+		os.Exit(2)
+	}
+	printRuleEntry(ruleID, entry)
+}
+
+func printRuleEntry(id string, e linter.RuleEntry) {
+	sev := strings.ToLower(string(e.Severity))
+	header := fmt.Sprintf("%s  [%s]  %s", id, sev, e.Title)
+	rule := fmt.Sprintf("\n%s\n%s\n\n%s\n",
+		header,
+		strings.Repeat("─", len(header)),
+		e.Description,
+	)
+	fmt.Print(rule)
+
+	if e.Example != "" {
+		fmt.Println("Example:")
+		fmt.Println()
+		for _, line := range strings.Split(e.Example, "\n") {
+			fmt.Printf("  %s\n", line)
+		}
+		fmt.Println()
+	}
+
+	if e.Fix != "" {
+		fmt.Println("Fix:")
+		fmt.Println()
+		for _, line := range strings.Split(e.Fix, "\n") {
+			fmt.Printf("  %s\n", line)
+		}
+		fmt.Println()
+	}
+}
+
+func printRuleList() {
+	ids := make([]string, 0, len(linter.RuleCatalog))
+	for id := range linter.RuleCatalog {
+		ids = append(ids, id)
+	}
+	sort.Strings(ids)
+
+	fmt.Printf("glint %s — lint rules\n\n", version)
+	for _, id := range ids {
+		e := linter.RuleCatalog[id]
+		sev := strings.ToLower(string(e.Severity))
+		fmt.Printf("  %-6s  [%-7s]  %s\n", id, sev, e.Title)
+	}
+	fmt.Println("\nUse 'glint explain <RULE>' for details on a specific rule.")
+}

cmd/glint/filter.go

@@ -0,0 +1,87 @@
+package main
+
+import (
+	"strings"
+
+	"git.k3nny.fr/glint/internal/config"
+	"git.k3nny.fr/glint/internal/linter"
+)
+
+// applyConfig filters and adjusts findings according to the project config
+// and inline suppression comments parsed from the pipeline YAML.
+//
+// Processing order:
+//  1. Build a combined ignore set from config.Ignore and any severity entry
+//     whose value is "ignore".
+//  2. Drop findings whose rule is in the ignore set.
+//  3. Drop findings suppressed by an inline "# glint: ignore" comment on the
+//     job definition (from p.Suppressions).
+//  4. Apply severity overrides ("error" / "warning") from config.Severity.
+func applyConfig(findings []linter.Finding, cfg config.Config, suppressions map[string][]string) []linter.Finding {
+	// Build the global ignore set (uppercased rule IDs).
+	ignoreSet := make(map[string]bool, len(cfg.Ignore))
+	for _, r := range cfg.Ignore {
+		ignoreSet[strings.ToUpper(r)] = true
+	}
+	// Severity entries with value "ignore" are equivalent to Ignore entries.
+	sevMap := make(map[string]string, len(cfg.Severity)) // upperRule → lowerLevel
+	for rule, sev := range cfg.Severity {
+		upper := strings.ToUpper(rule)
+		lower := strings.ToLower(sev)
+		sevMap[upper] = lower
+		if lower == "ignore" {
+			ignoreSet[upper] = true
+		}
+	}
+
+	if len(ignoreSet) == 0 && len(sevMap) == 0 && len(suppressions) == 0 {
+		return findings
+	}
+
+	kept := findings[:0:0] // reuse underlying array but return fresh slice
+	for _, f := range findings {
+		ruleUpper := strings.ToUpper(f.Rule)
+
+		// Global ignore.
+		if ignoreSet[ruleUpper] {
+			continue
+		}
+
+		// Inline suppression.
+		if isSuppressed(f.Job, ruleUpper, suppressions) {
+			continue
+		}
+
+		// Severity override.
+		if level, ok := sevMap[ruleUpper]; ok {
+			switch level {
+			case "error":
+				f.Severity = linter.Error
+			case "warning":
+				f.Severity = linter.Warning
+			}
+		}
+
+		kept = append(kept, f)
+	}
+	return kept
+}
+
+// isSuppressed reports whether jobName has a "# glint: ignore" directive that
+// covers ruleUpper. The wildcard entry "*" (from "# glint: ignore all")
+// suppresses every rule.
+func isSuppressed(jobName, ruleUpper string, suppressions map[string][]string) bool {
+	if jobName == "" || len(suppressions) == 0 {
+		return false
+	}
+	rules, ok := suppressions[jobName]
+	if !ok {
+		return false
+	}
+	for _, r := range rules {
+		if r == "*" || r == ruleUpper {
+			return true
+		}
+	}
+	return false
+}

cmd/glint/filter_test.go

@@ -0,0 +1,116 @@
+package main
+
+import (
+	"testing"
+
+	"git.k3nny.fr/glint/internal/config"
+	"git.k3nny.fr/glint/internal/linter"
+)
+
+func TestApplyConfig(t *testing.T) {
+	findings := []linter.Finding{
+		{Severity: linter.Error, Rule: "GL004", Job: "deploy", File: "ci.yml", Line: 10, Message: "bad stage"},
+		{Severity: linter.Warning, Rule: "GL007", Job: "old-job", File: "ci.yml", Line: 20, Message: "deprecated"},
+		{Severity: linter.Warning, Rule: "GL032", Job: "check", File: "ci.yml", Line: 30, Message: "var ref"},
+	}
+
+	t.Run("no config — pass through", func(t *testing.T) {
+		got := applyConfig(findings, config.Config{}, nil)
+		if len(got) != 3 {
+			t.Errorf("got %d findings, want 3", len(got))
+		}
+	})
+
+	t.Run("ignore GL007", func(t *testing.T) {
+		cfg := config.Config{Ignore: []string{"GL007"}}
+		got := applyConfig(findings, cfg, nil)
+		if len(got) != 2 {
+			t.Fatalf("got %d findings, want 2", len(got))
+		}
+		for _, f := range got {
+			if f.Rule == "GL007" {
+				t.Error("GL007 should be suppressed")
+			}
+		}
+	})
+
+	t.Run("ignore case-insensitive", func(t *testing.T) {
+		cfg := config.Config{Ignore: []string{"gl007"}}
+		got := applyConfig(findings, cfg, nil)
+		if len(got) != 2 {
+			t.Fatalf("got %d, want 2", len(got))
+		}
+	})
+
+	t.Run("severity demote error to warning", func(t *testing.T) {
+		cfg := config.Config{Severity: map[string]string{"GL004": "warning"}}
+		got := applyConfig(findings, cfg, nil)
+		if len(got) != 3 {
+			t.Fatalf("got %d findings, want 3", len(got))
+		}
+		if got[0].Severity != linter.Warning {
+			t.Errorf("GL004 severity = %s, want WARNING", got[0].Severity)
+		}
+	})
+
+	t.Run("severity promote warning to error", func(t *testing.T) {
+		cfg := config.Config{Severity: map[string]string{"GL007": "error"}}
+		got := applyConfig(findings, cfg, nil)
+		if got[1].Severity != linter.Error {
+			t.Errorf("GL007 severity = %s, want ERROR", got[1].Severity)
+		}
+	})
+
+	t.Run("severity ignore is equivalent to ignore list", func(t *testing.T) {
+		cfg := config.Config{Severity: map[string]string{"GL032": "ignore"}}
+		got := applyConfig(findings, cfg, nil)
+		if len(got) != 2 {
+			t.Fatalf("got %d, want 2", len(got))
+		}
+		for _, f := range got {
+			if f.Rule == "GL032" {
+				t.Error("GL032 should be suppressed via severity=ignore")
+			}
+		}
+	})
+
+	t.Run("inline suppression by job", func(t *testing.T) {
+		suppressions := map[string][]string{
+			"old-job": {"GL007"},
+		}
+		got := applyConfig(findings, config.Config{}, suppressions)
+		if len(got) != 2 {
+			t.Fatalf("got %d, want 2", len(got))
+		}
+		for _, f := range got {
+			if f.Job == "old-job" && f.Rule == "GL007" {
+				t.Error("old-job GL007 should be suppressed")
+			}
+		}
+	})
+
+	t.Run("inline suppression wildcard", func(t *testing.T) {
+		suppressions := map[string][]string{
+			"old-job": {"*"},
+		}
+		got := applyConfig(findings, config.Config{}, suppressions)
+		// old-job had GL007; should be gone
+		if len(got) != 2 {
+			t.Fatalf("got %d, want 2", len(got))
+		}
+	})
+
+	t.Run("pipeline-level findings not suppressed by job comment", func(t *testing.T) {
+		pipelineFindings := []linter.Finding{
+			{Severity: linter.Error, Rule: "GL001", Job: "", File: "ci.yml", Line: 0, Message: "no stages"},
+		}
+		suppressions := map[string][]string{
+			"": {"GL001"}, // empty job key should not match pipeline-level
+		}
+		got := applyConfig(pipelineFindings, config.Config{}, suppressions)
+		// Pipeline-level findings (f.Job == "") are never suppressed by job comments.
+		if len(got) != 1 {
+			t.Errorf("got %d, want 1 (pipeline-level finding must not be suppressed)", len(got))
+		}
+	})
+}

cmd/glint/format.go

@@ -0,0 +1,332 @@
+package main
+
+import (
+	"encoding/json"
+	"encoding/xml"
+	"fmt"
+	"io"
+	"strings"
+
+	"git.k3nny.fr/glint/internal/linter"
+)
+
+// --- JSON ---
+
+type jsonReport struct {
+	SchemaVersion int           `json:"schema_version"`
+	GlintVersion  string        `json:"glint_version"`
+	Pipeline      string        `json:"pipeline"`
+	Findings      []jsonFinding `json:"findings"`
+	Summary       jsonSummary   `json:"summary"`
+}
+
+type jsonFinding struct {
+	Rule     string `json:"rule,omitempty"`
+	Severity string `json:"severity"`
+	File     string `json:"file,omitempty"`
+	Line     int    `json:"line,omitempty"`
+	Job      string `json:"job,omitempty"`
+	Message  string `json:"message"`
+}
+
+type jsonSummary struct {
+	Total    int `json:"total"`
+	Errors   int `json:"errors"`
+	Warnings int `json:"warnings"`
+}
+
+func writeJSON(w io.Writer, findings []linter.Finding, pipeline string) {
+	errs, warns := countSeverities(findings)
+	jf := make([]jsonFinding, 0, len(findings))
+	for _, f := range findings {
+		jf = append(jf, jsonFinding{
+			Rule:     f.Rule,
+			Severity: strings.ToLower(string(f.Severity)),
+			File:     f.File,
+			Line:     f.Line,
+			Job:      f.Job,
+			Message:  f.Message,
+		})
+	}
+	report := jsonReport{
+		SchemaVersion: 1,
+		GlintVersion:  version,
+		Pipeline:      pipeline,
+		Findings:      jf,
+		Summary:       jsonSummary{Total: len(findings), Errors: errs, Warnings: warns},
+	}
+	enc := json.NewEncoder(w)
+	enc.SetIndent("", "  ")
+	_ = enc.Encode(report)
+}
+
+// --- SARIF 2.1.0 ---
+
+type sarifLog struct {
+	Schema  string     `json:"$schema"`
+	Version string     `json:"version"`
+	Runs    []sarifRun `json:"runs"`
+}
+
+type sarifRun struct {
+	Tool    sarifTool     `json:"tool"`
+	Results []sarifResult `json:"results"`
+}
+
+type sarifTool struct {
+	Driver sarifDriver `json:"driver"`
+}
+
+type sarifDriver struct {
+	Name           string      `json:"name"`
+	Version        string      `json:"version"`
+	InformationURI string      `json:"informationUri"`
+	Rules          []sarifRule `json:"rules"`
+}
+
+type sarifRule struct {
+	ID               string       `json:"id"`
+	ShortDescription sarifMessage `json:"shortDescription"`
+	HelpURI          string       `json:"helpUri,omitempty"`
+}
+
+type sarifMessage struct {
+	Text string `json:"text"`
+}
+
+type sarifResult struct {
+	RuleID    string          `json:"ruleId,omitempty"`
+	Level     string          `json:"level"`
+	Message   sarifMessage    `json:"message"`
+	Locations []sarifLocation `json:"locations,omitempty"`
+}
+
+type sarifLocation struct {
+	PhysicalLocation sarifPhysLoc `json:"physicalLocation"`
+}
+
+type sarifPhysLoc struct {
+	ArtifactLocation sarifArtifact `json:"artifactLocation"`
+	Region           *sarifRegion  `json:"region,omitempty"`
+}
+
+type sarifArtifact struct {
+	URI       string `json:"uri"`
+	URIBaseID string `json:"uriBaseId,omitempty"`
+}
+
+type sarifRegion struct {
+	StartLine int `json:"startLine"`
+}
+
+func writeSARIF(w io.Writer, findings []linter.Finding, _ string) {
+	// Collect unique rule IDs (preserving first-seen order).
+	seenRules := map[string]bool{}
+	var rules []sarifRule
+	for _, f := range findings {
+		if f.Rule != "" && !seenRules[f.Rule] {
+			seenRules[f.Rule] = true
+			rules = append(rules, sarifRule{
+				ID:               f.Rule,
+				ShortDescription: sarifMessage{Text: "glint rule " + f.Rule},
+				HelpURI:          "https://git.k3nny.fr/glint",
+			})
+		}
+	}
+	if rules == nil {
+		rules = []sarifRule{}
+	}
+
+	var results []sarifResult
+	for _, f := range findings {
+		level := "warning"
+		if f.Severity == linter.Error {
+			level = "error"
+		}
+		msg := f.Message
+		if f.Job != "" {
+			msg = fmt.Sprintf("job %q: %s", f.Job, msg)
+		}
+		result := sarifResult{
+			RuleID:  f.Rule,
+			Level:   level,
+			Message: sarifMessage{Text: msg},
+		}
+		if f.File != "" {
+			loc := sarifLocation{
+				PhysicalLocation: sarifPhysLoc{
+					ArtifactLocation: sarifArtifact{URI: f.File, URIBaseID: "%SRCROOT%"},
+				},
+			}
+			if f.Line > 0 {
+				loc.PhysicalLocation.Region = &sarifRegion{StartLine: f.Line}
+			}
+			result.Locations = []sarifLocation{loc}
+		}
+		results = append(results, result)
+	}
+	if results == nil {
+		results = []sarifResult{}
+	}
+
+	log := sarifLog{
+		Schema:  "https://json.schemastore.org/sarif-2.1.0.json",
+		Version: "2.1.0",
+		Runs: []sarifRun{{
+			Tool: sarifTool{Driver: sarifDriver{
+				Name:           "glint",
+				Version:        strings.TrimPrefix(version, "v"),
+				InformationURI: "https://git.k3nny.fr/glint",
+				Rules:          rules,
+			}},
+			Results: results,
+		}},
+	}
+	enc := json.NewEncoder(w)
+	enc.SetIndent("", "  ")
+	_ = enc.Encode(log)
+}
+
+// --- JUnit XML ---
+
+type junitTestsuites struct {
+	XMLName  xml.Name         `xml:"testsuites"`
+	Name     string           `xml:"name,attr"`
+	Tests    int              `xml:"tests,attr"`
+	Failures int              `xml:"failures,attr"`
+	Time     string           `xml:"time,attr"`
+	Suites   []junitTestsuite `xml:"testsuite"`
+}
+
+type junitTestsuite struct {
+	Name     string          `xml:"name,attr"`
+	Tests    int             `xml:"tests,attr"`
+	Failures int             `xml:"failures,attr"`
+	Time     string          `xml:"time,attr"`
+	Cases    []junitTestcase `xml:"testcase"`
+}
+
+type junitTestcase struct {
+	Name      string        `xml:"name,attr"`
+	Classname string        `xml:"classname,attr"`
+	Failure   *junitFailure `xml:"failure,omitempty"`
+}
+
+type junitFailure struct {
+	Message string `xml:"message,attr"`
+	Type    string `xml:"type,attr"`
+	Body    string `xml:",chardata"`
+}
+
+func writeJUnit(w io.Writer, findings []linter.Finding, pipeline string) {
+	_, fails := countSeverities(findings)
+	_ = fails // re-derive below to count both errors and warnings as failures
+
+	var cases []junitTestcase
+	if len(findings) == 0 {
+		cases = []junitTestcase{{Name: "no issues found", Classname: pipeline}}
+	} else {
+		for _, f := range findings {
+			name := f.Rule
+			if name == "" {
+				name = "lint"
+			}
+			classname := f.File
+			if classname == "" {
+				classname = pipeline
+			}
+			if f.Job != "" {
+				classname += "#" + f.Job
+			}
+			msg := f.Message
+			if f.Job != "" {
+				msg = fmt.Sprintf("job %q: %s", f.Job, msg)
+			}
+			cases = append(cases, junitTestcase{
+				Name:      name,
+				Classname: classname,
+				Failure: &junitFailure{
+					Message: msg,
+					Type:    strings.ToLower(string(f.Severity)),
+					Body:    f.String(),
+				},
+			})
+		}
+	}
+
+	suite := junitTestsuite{
+		Name:     pipeline,
+		Tests:    len(cases),
+		Failures: len(findings), // all findings are failures
+		Time:     "0",
+		Cases:    cases,
+	}
+	suites := junitTestsuites{
+		Name:     "glint",
+		Tests:    len(cases),
+		Failures: len(findings),
+		Time:     "0",
+		Suites:   []junitTestsuite{suite},
+	}
+
+	fmt.Fprint(w, `<?xml version="1.0" encoding="UTF-8"?>`)
+	fmt.Fprintln(w)
+	enc := xml.NewEncoder(w)
+	enc.Indent("", "  ")
+	_ = enc.Encode(suites)
+	_ = enc.Flush()
+	fmt.Fprintln(w)
+}
+
+// --- GitHub Actions annotations ---
+
+// writeGitHub emits GitHub Actions workflow command annotation lines.
+// Each finding becomes an ::error:: or ::warning:: line that GitHub CI
+// renders as an inline comment on the relevant file in pull requests.
+func writeGitHub(w io.Writer, findings []linter.Finding) {
+	for _, f := range findings {
+		level := "warning"
+		if f.Severity == linter.Error {
+			level = "error"
+		}
+		msg := f.Message
+		if f.Job != "" {
+			msg = fmt.Sprintf("job %q: %s", f.Job, msg)
+		}
+		// GitHub annotation messages must not contain raw newlines, percent signs,
+		// carriage returns, or colons in the parameter block.
+		msg = strings.ReplaceAll(msg, "%", "%25")
+		msg = strings.ReplaceAll(msg, "\r", "%0D")
+		msg = strings.ReplaceAll(msg, "\n", "%0A")
+
+		var params []string
+		if f.File != "" {
+			params = append(params, "file="+f.File)
+			if f.Line > 0 {
+				params = append(params, fmt.Sprintf("line=%d", f.Line))
+			}
+		}
+		if f.Rule != "" {
+			params = append(params, "title="+f.Rule)
+		}
+
+		paramStr := ""
+		if len(params) > 0 {
+			paramStr = " " + strings.Join(params, ",")
+		}
+		fmt.Fprintf(w, "::%s%s::%s\n", level, paramStr, msg)
+	}
+}
+
+// --- shared helpers ---
+
+func countSeverities(findings []linter.Finding) (errors, warnings int) {
+	for _, f := range findings {
+		if f.Severity == linter.Error {
+			errors++
+		} else {
+			warnings++
+		}
+	}
+	return
+}

cmd/glint/format_test.go

@@ -0,0 +1,228 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"encoding/xml"
+	"strings"
+	"testing"
+
+	"git.k3nny.fr/glint/internal/linter"
+)
+
+var testFindings = []linter.Finding{
+	{
+		Severity: linter.Error,
+		Rule:     "GL004",
+		Job:      "deploy",
+		File:     ".gitlab-ci.yml",
+		Line:     14,
+		Message:  `stage "production" is not defined in 'stages'`,
+	},
+	{
+		Severity: linter.Warning,
+		Rule:     "GL007",
+		Job:      "old-job",
+		File:     ".gitlab-ci.yml",
+		Line:     31,
+		Message:  "'only'/'except' are deprecated; prefer 'rules'",
+	},
+}
+
+func TestWriteJSON(t *testing.T) {
+	t.Run("findings", func(t *testing.T) {
+		var buf bytes.Buffer
+		writeJSON(&buf, testFindings, ".gitlab-ci.yml")
+
+		var got jsonReport
+		if err := json.Unmarshal(buf.Bytes(), &got); err != nil {
+			t.Fatalf("invalid JSON: %v", err)
+		}
+		if got.SchemaVersion != 1 {
+			t.Errorf("schema_version = %d, want 1", got.SchemaVersion)
+		}
+		if len(got.Findings) != 2 {
+			t.Fatalf("got %d findings, want 2", len(got.Findings))
+		}
+		if got.Summary.Errors != 1 || got.Summary.Warnings != 1 {
+			t.Errorf("summary = %+v, want {2,1,1}", got.Summary)
+		}
+		if got.Findings[0].Rule != "GL004" || got.Findings[0].Severity != "error" {
+			t.Errorf("finding[0] = %+v", got.Findings[0])
+		}
+		if got.Findings[0].Job != "deploy" || got.Findings[0].Line != 14 {
+			t.Errorf("finding[0] job/line = %s/%d", got.Findings[0].Job, got.Findings[0].Line)
+		}
+	})
+
+	t.Run("empty", func(t *testing.T) {
+		var buf bytes.Buffer
+		writeJSON(&buf, nil, "ci.yml")
+
+		var got jsonReport
+		if err := json.Unmarshal(buf.Bytes(), &got); err != nil {
+			t.Fatalf("invalid JSON: %v", err)
+		}
+		if got.Findings == nil {
+			t.Error("findings must be [] not null")
+		}
+		if got.Summary.Total != 0 {
+			t.Errorf("total = %d, want 0", got.Summary.Total)
+		}
+	})
+}
+
+func TestWriteSARIF(t *testing.T) {
+	t.Run("findings", func(t *testing.T) {
+		var buf bytes.Buffer
+		writeSARIF(&buf, testFindings, ".gitlab-ci.yml")
+
+		var got sarifLog
+		if err := json.Unmarshal(buf.Bytes(), &got); err != nil {
+			t.Fatalf("invalid JSON: %v", err)
+		}
+		if got.Version != "2.1.0" {
+			t.Errorf("version = %q, want 2.1.0", got.Version)
+		}
+		if len(got.Runs) != 1 {
+			t.Fatalf("runs count = %d, want 1", len(got.Runs))
+		}
+		run := got.Runs[0]
+		if run.Tool.Driver.Name != "glint" {
+			t.Errorf("driver.name = %q", run.Tool.Driver.Name)
+		}
+		if len(run.Results) != 2 {
+			t.Fatalf("results count = %d, want 2", len(run.Results))
+		}
+		r0 := run.Results[0]
+		if r0.RuleID != "GL004" || r0.Level != "error" {
+			t.Errorf("result[0] ruleId/level = %s/%s", r0.RuleID, r0.Level)
+		}
+		if len(r0.Locations) != 1 {
+			t.Fatalf("result[0] locations count = %d, want 1", len(r0.Locations))
+		}
+		loc := r0.Locations[0].PhysicalLocation
+		if loc.ArtifactLocation.URI != ".gitlab-ci.yml" {
+			t.Errorf("artifactLocation.uri = %q", loc.ArtifactLocation.URI)
+		}
+		if loc.Region == nil || loc.Region.StartLine != 14 {
+			t.Errorf("region = %v", loc.Region)
+		}
+		// Message should include job name prefix.
+		if !strings.Contains(r0.Message.Text, `job "deploy"`) {
+			t.Errorf("message missing job prefix: %q", r0.Message.Text)
+		}
+	})
+
+	t.Run("empty", func(t *testing.T) {
+		var buf bytes.Buffer
+		writeSARIF(&buf, nil, "ci.yml")
+
+		var got sarifLog
+		if err := json.Unmarshal(buf.Bytes(), &got); err != nil {
+			t.Fatalf("invalid JSON: %v", err)
+		}
+		run := got.Runs[0]
+		if run.Results == nil {
+			t.Error("results must be [] not null")
+		}
+		if run.Tool.Driver.Rules == nil {
+			t.Error("rules must be [] not null")
+		}
+	})
+}
+
+func TestWriteJUnit(t *testing.T) {
+	t.Run("findings", func(t *testing.T) {
+		var buf bytes.Buffer
+		writeJUnit(&buf, testFindings, ".gitlab-ci.yml")
+
+		if !strings.HasPrefix(buf.String(), "<?xml") {
+			t.Error("output does not start with XML declaration")
+		}
+
+		var got junitTestsuites
+		if err := xml.Unmarshal(buf.Bytes(), &got); err != nil {
+			t.Fatalf("invalid XML: %v\noutput:\n%s", err, buf.String())
+		}
+		if got.Failures != 2 {
+			t.Errorf("failures = %d, want 2", got.Failures)
+		}
+		if len(got.Suites) != 1 {
+			t.Fatalf("suites count = %d, want 1", len(got.Suites))
+		}
+		suite := got.Suites[0]
+		if len(suite.Cases) != 2 {
+			t.Fatalf("test cases count = %d, want 2", len(suite.Cases))
+		}
+		if suite.Cases[0].Name != "GL004" {
+			t.Errorf("case[0].name = %q", suite.Cases[0].Name)
+		}
+		if suite.Cases[0].Failure == nil {
+			t.Error("case[0] has no failure element")
+		}
+	})
+
+	t.Run("empty_is_passing", func(t *testing.T) {
+		var buf bytes.Buffer
+		writeJUnit(&buf, nil, "ci.yml")
+
+		var got junitTestsuites
+		if err := xml.Unmarshal(buf.Bytes(), &got); err != nil {
+			t.Fatalf("invalid XML: %v", err)
+		}
+		if got.Failures != 0 {
+			t.Errorf("failures = %d, want 0", got.Failures)
+		}
+		suite := got.Suites[0]
+		if len(suite.Cases) != 1 || suite.Cases[0].Failure != nil {
+			t.Error("expected exactly one passing testcase when no findings")
+		}
+	})
+}
+
+func TestWriteGitHub(t *testing.T) {
+	cases := []struct {
+		name     string
+		findings []linter.Finding
+		wantLine string
+	}{
+		{
+			name:     "error with file and line",
+			findings: []linter.Finding{testFindings[0]},
+			wantLine: "::error file=.gitlab-ci.yml,line=14,title=GL004::job \"deploy\": stage \"production\" is not defined in 'stages'",
+		},
+		{
+			name:     "warning",
+			findings: []linter.Finding{testFindings[1]},
+			wantLine: "::warning file=.gitlab-ci.yml,line=31,title=GL007::job \"old-job\": 'only'/'except' are deprecated; prefer 'rules'",
+		},
+		{
+			name: "no file or line",
+			findings: []linter.Finding{{
+				Severity: linter.Error,
+				Rule:     "GL001",
+				Message:  "no stages defined",
+			}},
+			wantLine: "::error title=GL001::no stages defined",
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			var buf bytes.Buffer
+			writeGitHub(&buf, tc.findings)
+			got := strings.TrimRight(buf.String(), "\n")
+			if got != tc.wantLine {
+				t.Errorf("\ngot:  %s\nwant: %s", got, tc.wantLine)
+			}
+		})
+	}
+}
+
+func TestCountSeverities(t *testing.T) {
+	errs, warns := countSeverities(testFindings)
+	if errs != 1 || warns != 1 {
+		t.Errorf("countSeverities = (%d, %d), want (1, 1)", errs, warns)
+	}
+}

cmd/glint/main.go

@@ -9,6 +9,7 @@ import (
 	"strings"
 
 	"git.k3nny.fr/glint/internal/cicontext"
+	"git.k3nny.fr/glint/internal/config"
 	"git.k3nny.fr/glint/internal/fetcher"
 	"git.k3nny.fr/glint/internal/graph"
 	"git.k3nny.fr/glint/internal/linter"
@@ -16,6 +17,21 @@ import (
 	"git.k3nny.fr/glint/internal/resolver"
 )
 
+// version is set at build time via -ldflags "-X main.version=vX.Y.Z".
+var version = "dev"
+
+// defaultCacheDir returns the platform-default glint cache directory:
+// $XDG_CACHE_HOME/glint or ~/.cache/glint.
+func defaultCacheDir() string {
+	if xdg := os.Getenv("XDG_CACHE_HOME"); xdg != "" {
+		return filepath.Join(xdg, "glint")
+	}
+	if home, err := os.UserHomeDir(); err == nil {
+		return filepath.Join(home, ".cache", "glint")
+	}
+	return ""
+}
+
 const globalUsage = `glint: Lint and visualise GitLab CI pipelines locally.
 
 Usage: glint [OPTIONS] <COMMAND>
@@ -23,9 +39,11 @@ Usage: glint [OPTIONS] <COMMAND>
 Commands:
   check    Lint a pipeline file — exits 0 (clean) or 1 (errors found)
   graph    Visualise the pipeline as a job tree or Mermaid graph
+  explain  Show description and fix for a lint rule (e.g. glint explain GL007)
 
 Options:
   -h, --help     Print help
+  -v, --version  Print version
 
 For help with a specific command, see: ` + "`glint <command> --help`" + `.
 `
@@ -40,8 +58,13 @@ func main() {
 		cmdCheck(os.Args[2:])
 	case "graph":
 		cmdGraph(os.Args[2:])
+	case "explain":
+		cmdExplain(os.Args[2:])
 	case "-h", "--help", "help":
+		fmt.Fprintf(os.Stderr, "glint %s\n\n", version)
 		fmt.Fprint(os.Stderr, globalUsage)
+	case "-v", "--version", "version":
+		fmt.Printf("glint %s\n", version)
 	default:
 		fmt.Fprintf(os.Stderr, "glint: unknown command %q\n\n%s", os.Args[1], globalUsage)
 		os.Exit(2)
@@ -61,12 +84,17 @@ func cmdCheck(args []string) {
 	fs := flag.NewFlagSet("glint check", flag.ExitOnError)
 	token := fs.String("token", "", "GitLab personal access token (overrides GITLAB_TOKEN)")
 	gitlabURL := fs.String("gitlab-url", "", "GitLab instance URL (overrides CI_SERVER_URL / GITLAB_URL)")
+	cacheDir := fs.String("cache-dir", "", "directory to cache fetched remote includes (created if needed)")
+	offline := fs.Bool("offline", false, "skip all network calls; serve only from --cache-dir")
+	format := fs.String("format", "text", "output format: text, json, sarif, junit, github")
 	branch := fs.String("branch", "", "simulate a branch push (sets CI_COMMIT_BRANCH, …)")
 	tag := fs.String("tag", "", "simulate a tag push (sets CI_COMMIT_TAG, …)")
 	source := fs.String("source", "", "set CI_PIPELINE_SOURCE")
+	listVars := fs.Bool("list-vars", false, "print all collected pipeline variables (from root and included files) to stderr, then continue")
 	var vars multiFlag
 	fs.Var(&vars, "var", "set a CI variable as KEY=VALUE; repeatable")
 	fs.Usage = func() {
+		fmt.Fprintf(os.Stderr, "glint %s\n\n", version)
 		fmt.Fprint(os.Stderr, `Lint a GitLab CI pipeline file.
 
 Resolves local includes and extends chains, then runs all lint rules.
@@ -78,6 +106,10 @@ Arguments:
   <PIPELINE>  Path to the .gitlab-ci.yml file to lint
 
 Options:
+      --format <FORMAT>
+          Output format for findings.
+          [default: text] [possible values: text, json, sarif, junit, github]
+
       --token <TOKEN>
           GitLab personal access token. Required to fetch project: includes;
           component: includes are attempted unauthenticated.
@@ -87,9 +119,21 @@ Options:
           GitLab instance URL.
           [env: CI_SERVER_URL | GITLAB_URL] [default: https://gitlab.com]
 
+      --cache-dir <DIR>
+          Cache fetched remote templates (project: and component: includes) in
+          DIR. The directory is created on first use. Subsequent runs read from
+          cache first, avoiding repeated network calls.
+
+      --offline
+          Do not make any network calls. All remote includes must already be
+          present in --cache-dir; missing entries emit a warning (same as
+          having no token). Implies the default cache dir (~/.cache/glint) when
+          --cache-dir is not set.
+
       --branch <NAME>
           Simulate a branch push. Populates: CI_COMMIT_BRANCH,
           CI_COMMIT_REF_NAME, CI_COMMIT_REF_SLUG, CI_PIPELINE_SOURCE=push.
+          [default: main]
 
       --tag <NAME>
           Simulate a tag push. Populates: CI_COMMIT_TAG, CI_COMMIT_REF_NAME,
@@ -97,32 +141,90 @@ Options:
 
       --source <EVENT>
           Override CI_PIPELINE_SOURCE.
-          [possible values: push, merge_request_event, schedule, web, api]
+          [default: push] [possible values: push, merge_request_event, schedule, web, api]
 
       --var <KEY=VALUE>
           Set or override a CI variable. Takes precedence over --branch, --tag,
           and --source. Repeatable.
 
+      --list-vars
+          Print all pipeline-level variables collected from the root file and
+          every included file (sorted KEY=VALUE) to stderr, then continue
+          normally. Useful for debugging variable resolution and GL032 findings.
+
   -h, --help
           Print help
 
+Note: when none of --branch, --tag, --source, or --var are given, glint
+defaults to --branch main --source push so that rules:if: expressions are
+always evaluated.
+
 Examples:
   glint check .gitlab-ci.yml
-  glint check --branch main .gitlab-ci.yml
+  glint check --format json .gitlab-ci.yml
+  glint check --format sarif .gitlab-ci.yml | upload-to-github-code-scanning
+  glint check --format junit .gitlab-ci.yml > junit.xml
+  glint check --format github .gitlab-ci.yml
+  glint check --branch develop .gitlab-ci.yml
+  glint check --tag v1.0.0 .gitlab-ci.yml
+  glint check --source merge_request_event .gitlab-ci.yml
+  glint check --list-vars .gitlab-ci.yml
   GITLAB_TOKEN=glpat-xxxx glint check .gitlab-ci.yml
   glint check --token glpat-xxxx --gitlab-url https://gitlab.example.com .gitlab-ci.yml
   glint check --branch main --var DEPLOY_ENV=production .gitlab-ci.yml
+  glint check --cache-dir ~/.cache/glint .gitlab-ci.yml
+  glint check --offline --cache-dir ~/.cache/glint .gitlab-ci.yml
 `)
 	}
 	_ = fs.Parse(args)
 
+	// Apply implicit defaults when no context flag is given at all.
+	if *branch == "" && *tag == "" && *source == "" && len(vars) == 0 {
+		*branch = "main"
+		*source = "push"
+	}
+
+	validFormats := map[string]bool{
+		"text": true, "json": true, "sarif": true, "junit": true, "github": true,
+	}
+	if !validFormats[*format] {
+		fmt.Fprintf(os.Stderr, "glint: unknown format %q; valid: text, json, sarif, junit, github\n", *format)
+		os.Exit(2)
+	}
+
 	if fs.NArg() != 1 {
 		fs.Usage()
 		os.Exit(2)
 	}
 	path := fs.Arg(0)
+	rootDir := filepath.Dir(filepath.Clean(path))
 
-	cfg := fetcher.AutoConfig().WithOverrides(*gitlabURL, *token)
+	// Load project config (.glint.yml), searching from the pipeline directory
+	// up to the git root.
+	glintCfg, cfgErr := config.Load(rootDir)
+	if cfgErr != nil {
+		fmt.Fprintf(os.Stderr, "%s: [warning] %s: %v\n", path, config.Filename, cfgErr)
+	}
+
+	// CLI flags take priority over config file values, which take priority over
+	// environment variables (read by AutoConfig).
+	fetcherToken := *token
+	if fetcherToken == "" {
+		fetcherToken = glintCfg.Token
+	}
+	fetcherURL := *gitlabURL
+	if fetcherURL == "" {
+		fetcherURL = glintCfg.URL
+	}
+	resolvedCacheDir := *cacheDir
+	if resolvedCacheDir == "" {
+		resolvedCacheDir = glintCfg.CacheDir
+	}
+	if *offline && resolvedCacheDir == "" {
+		resolvedCacheDir = defaultCacheDir()
+	}
+
+	cfg := fetcher.AutoConfig().WithOverrides(fetcherURL, fetcherToken, resolvedCacheDir, *offline)
 
 	p, err := model.Parse(path)
 	if err != nil {
@@ -130,10 +232,22 @@ Examples:
 		os.Exit(2)
 	}
 
-	rootDir := filepath.Dir(filepath.Clean(path))
+	// Merge config-defined stages into the pipeline before linting so that
+	// GL004 does not fire for jobs in stages declared only in .glint.yml.
+	stageSet := make(map[string]bool, len(p.Stages))
+	for _, s := range p.Stages {
+		stageSet[s] = true
+	}
+	for _, s := range glintCfg.Stages {
+		if !stageSet[s] {
+			p.Stages = append(p.Stages, s)
+			stageSet[s] = true
+		}
+	}
+
 	warnings, _ := resolver.ResolveIncludes(p, cfg, rootDir)
 	for _, w := range warnings {
-		fmt.Fprintf(os.Stderr, "[WARNING] include %s\n", w)
+		fmt.Fprintf(os.Stderr, "%s: [warning] include %s\n", path, w)
 	}
 
 	extWarnings, err := resolver.Resolve(p)
@@ -142,36 +256,56 @@ Examples:
 		os.Exit(2)
 	}
 	for _, w := range extWarnings {
-		fmt.Fprintf(os.Stderr, "[WARNING] job %q extends unknown job %q; extends chain skipped\n", w.Job, w.Base)
+		fmt.Fprintf(os.Stderr, "%s: [warning] job %q extends unknown job %q; extends chain skipped\n", path, w.Job, w.Base)
 	}
 
 	ctx := cicontext.New(*branch, *tag, *source, vars)
 	if !ctx.IsEmpty() {
+		if !enrichContext(ctx, p) {
+			fmt.Fprintf(os.Stderr, "%s: [warning] workflow:rules: pipeline would not start for this context\n", path)
+		}
+	}
+	if *listVars {
+		printVars(p, ctx)
+	}
+	// Context summary only makes sense in plain-text output; suppress it in
+	// structured formats so stdout contains only the machine-readable payload.
+	if !ctx.IsEmpty() && *format == "text" {
 		printContext(p, ctx)
 	}
 
 	findings := linter.Lint(p)
-	hasErrors := false
+	findings = applyConfig(findings, glintCfg, p.Suppressions)
+	errCount, _ := countSeverities(findings)
+
+	// In structured formats the summary line goes to stderr so stdout is clean.
+	summaryOut := os.Stdout
+	if *format != "text" {
+		summaryOut = os.Stderr
+	}
+
+	switch *format {
+	case "json":
+		writeJSON(os.Stdout, findings, path)
+	case "sarif":
+		writeSARIF(os.Stdout, findings, path)
+	case "junit":
+		writeJUnit(os.Stdout, findings, path)
+	case "github":
+		writeGitHub(os.Stdout, findings)
+	default: // "text"
 		for _, f := range findings {
 			fmt.Println(f)
-		if f.Severity == linter.Error {
-			hasErrors = true
 		}
 	}
 
 	if len(findings) == 0 {
-		fmt.Printf("OK: %s — no issues found (%d job(s), %d stage(s))\n", path, len(p.Jobs), len(p.Stages))
+		fmt.Fprintf(summaryOut, "OK: %s — no issues found (%d job(s), %d stage(s))\n", path, len(p.Jobs), len(p.Stages))
 	} else {
-		errCount := 0
-		for _, f := range findings {
-			if f.Severity == linter.Error {
-				errCount++
-			}
-		}
-		fmt.Printf("%d finding(s): %d error(s)\n", len(findings), errCount)
+		fmt.Fprintf(summaryOut, "%d finding(s): %d error(s)\n", len(findings), errCount)
 	}
 
-	if hasErrors {
+	if errCount > 0 {
 		os.Exit(1)
 	}
 }
@@ -191,8 +325,11 @@ func cmdGraph(args []string) {
 	fs := flag.NewFlagSet("glint graph", flag.ExitOnError)
 	token := fs.String("token", "", "GitLab personal access token (overrides GITLAB_TOKEN)")
 	gitlabURL := fs.String("gitlab-url", "", "GitLab instance URL (overrides CI_SERVER_URL / GITLAB_URL)")
+	cacheDir := fs.String("cache-dir", "", "directory to cache fetched remote includes (created if needed)")
+	offline := fs.Bool("offline", false, "skip all network calls; serve only from --cache-dir")
 	out := fs.String("out", "glint-out", "output directory for Mermaid graph files (pipeline mode)")
 	fs.Usage = func() {
+		fmt.Fprintf(os.Stderr, "glint %s\n\n", version)
 		fmt.Fprint(os.Stderr, `Visualise the pipeline as a job tree and/or Mermaid graph.
 
 Usage: glint graph [MODE] [OPTIONS] <PIPELINE>
@@ -221,6 +358,7 @@ Options:
           evaluated state ([skipped] or [manual]; no tag means active).
           Populates: CI_COMMIT_BRANCH, CI_COMMIT_REF_NAME, CI_COMMIT_REF_SLUG,
           CI_PIPELINE_SOURCE=push.
+          [default: main]
 
       --tag <NAME>
           Simulate a tag push. Populates: CI_COMMIT_TAG, CI_COMMIT_REF_NAME,
@@ -228,18 +366,29 @@ Options:
 
       --source <EVENT>
           Override CI_PIPELINE_SOURCE.
-          [possible values: push, merge_request_event, schedule, web, api]
+          [default: push] [possible values: push, merge_request_event, schedule, web, api]
 
       --var <KEY=VALUE>
           Set or override a CI variable. Repeatable.
 
+      --list-vars
+          Print all pipeline-level variables collected from the root file and
+          every included file (sorted KEY=VALUE) to stderr, then continue
+          normally. Useful for debugging variable resolution.
+
   -h, --help
           Print help
 
+Note: when none of --branch, --tag, --source, or --var are given, glint
+defaults to --branch main --source push so that rules:if: expressions are
+always evaluated.
+
 Examples:
   glint graph .gitlab-ci.yml
   glint graph tree .gitlab-ci.yml
-  glint graph tree --branch main .gitlab-ci.yml
+  glint graph tree --branch develop .gitlab-ci.yml
+  glint graph tree --tag v1.0.0 .gitlab-ci.yml
+  glint graph tree --list-vars .gitlab-ci.yml
   glint graph includes .gitlab-ci.yml > includes.mmd
   glint graph pipeline .gitlab-ci.yml
   glint graph pipeline --out /tmp/graphs .gitlab-ci.yml
@@ -249,17 +398,29 @@ Examples:
 	branch := fs.String("branch", "", "simulate a branch push (sets CI_COMMIT_BRANCH, …)")
 	tag := fs.String("tag", "", "simulate a tag push (sets CI_COMMIT_TAG, …)")
 	source := fs.String("source", "", "set CI_PIPELINE_SOURCE")
+	listVars := fs.Bool("list-vars", false, "print all collected pipeline variables to stderr, then continue")
 	var vars multiFlag
 	fs.Var(&vars, "var", "set a CI variable as KEY=VALUE; repeatable")
 	_ = fs.Parse(args)
 
+	// Apply implicit defaults when no context flag is given at all.
+	if *branch == "" && *tag == "" && *source == "" && len(vars) == 0 {
+		*branch = "main"
+		*source = "push"
+	}
+
 	if fs.NArg() != 1 {
 		fs.Usage()
 		os.Exit(2)
 	}
 	path := fs.Arg(0)
 
-	cfg := fetcher.AutoConfig().WithOverrides(*gitlabURL, *token)
+	resolvedCacheDir := *cacheDir
+	if *offline && resolvedCacheDir == "" {
+		resolvedCacheDir = defaultCacheDir()
+	}
+
+	cfg := fetcher.AutoConfig().WithOverrides(*gitlabURL, *token, resolvedCacheDir, *offline)
 
 	p, err := model.Parse(path)
 	if err != nil {
@@ -272,6 +433,12 @@ Examples:
 	resolver.Resolve(p)                       //nolint:errcheck
 
 	ctx := cicontext.New(*branch, *tag, *source, vars)
+	if !ctx.IsEmpty() {
+		enrichContext(ctx, p)
+	}
+	if *listVars {
+		printVars(p, ctx)
+	}
 
 	switch mode {
 	case "default":
@@ -300,6 +467,85 @@ Examples:
 	}
 }
 
+// printVars prints the collected variable namespaces to stderr:
+//  1. Pipeline variables — declared in variables: blocks across the root file
+//     and all included files (merged by ResolveIncludes).
+//  2. Workflow-rule variables — union of variables: from every workflow:rules
+//     entry; any one of them may be injected at runtime.
+//  3. Effective context variables — only when ctx is non-empty; shows the
+//     fully merged set visible to job rules:if: after enrichContext.
+func printVars(p *model.Pipeline, ctx *cicontext.Context) {
+	fmt.Fprintln(os.Stderr, "Pipeline variables (YAML, root + includes):")
+	printVarMap(p.Variables)
+
+	if p.Workflow != nil {
+		union := map[string]any{}
+		for _, rule := range p.Workflow.Rules {
+			for k, v := range rule.Variables {
+				union[k] = v
+			}
+		}
+		if len(union) > 0 {
+			fmt.Fprintln(os.Stderr, "Workflow-rule variables (union across all rules):")
+			printVarMap(union)
+		}
+	}
+
+	if !ctx.IsEmpty() {
+		fmt.Fprintln(os.Stderr, "Effective context variables (after workflow + CLI flags):")
+		keys := make([]string, 0, len(ctx.Vars))
+		for k := range ctx.Vars {
+			keys = append(keys, k)
+		}
+		sort.Strings(keys)
+		for _, k := range keys {
+			fmt.Fprintf(os.Stderr, "  %s=%s\n", k, ctx.Vars[k])
+		}
+	}
+}
+
+func printVarMap(m map[string]any) {
+	keys := make([]string, 0, len(m))
+	for k := range m {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+	if len(keys) == 0 {
+		fmt.Fprintln(os.Stderr, "  (none)")
+		return
+	}
+	for _, k := range keys {
+		fmt.Fprintf(os.Stderr, "  %s=%s\n", k, varValueString(m[k]))
+	}
+}
+
+func varValueString(v any) string {
+	if s, ok := cicontext.ScalarString(v); ok {
+		return s
+	}
+	return "(complex)"
+}
+
+// enrichContext injects pipeline-level variable defaults and then
+// workflow-rule-generated variables into ctx before job evaluation.
+// Injection respects pinned variables (--branch/--tag/--source/--var always win).
+// Returns false when workflow:rules: would prevent the pipeline from starting.
+func enrichContext(ctx *cicontext.Context, p *model.Pipeline) bool {
+	// Pipeline variables: injected as defaults (lowest priority).
+	for k, v := range cicontext.ExtractStringVars(p.Variables) {
+		ctx.Inject(k, v)
+	}
+	// Workflow rules: evaluate to find which rule matches, then inject its variables.
+	runs, ruleVars := cicontext.EvalWorkflow(p, ctx)
+	for k, v := range ruleVars {
+		ctx.Inject(k, v)
+	}
+	// Expand $VAR / ${VAR} references within variable values now that all
+	// sources (pipeline, workflow rules, CLI) have been merged.
+	ctx.ExpandVars()
+	return runs
+}
+
 func printContext(p *model.Pipeline, ctx *cicontext.Context) {
 	fmt.Printf("Context: %s\n\n", ctx.Summary())
 

go.mod

@@ -2,4 +2,14 @@ module git.k3nny.fr/glint
 
 go 1.26.4
 
-require gopkg.in/yaml.v3 v3.0.1 // indirect
+require (
+	github.com/BurntSushi/toml v1.4.1-0.20240526193622-a339e1f7089c // indirect
+	golang.org/x/exp/typeparams v0.0.0-20231108232855-2478ac86f678 // indirect
+	golang.org/x/mod v0.31.0 // indirect
+	golang.org/x/sync v0.19.0 // indirect
+	golang.org/x/tools v0.40.1-0.20260108161641-ca281cf95054 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+	honnef.co/go/tools v0.7.0 // indirect
+)
+
+tool honnef.co/go/tools/cmd/staticcheck

go.sum

@@ -1,3 +1,16 @@
+github.com/BurntSushi/toml v1.4.1-0.20240526193622-a339e1f7089c h1:pxW6RcqyfI9/kWtOwnv/G+AzdKuy2ZrqINhenH4HyNs=
+github.com/BurntSushi/toml v1.4.1-0.20240526193622-a339e1f7089c/go.mod h1:ukJfTF/6rtPPRCnwkur4qwRxa8vTRFBF0uk2lLoLwho=
+golang.org/x/exp v0.0.0-20231110203233-9a3e6036ecaa h1:FRnLl4eNAQl8hwxVVC17teOw8kdjVDVAiFMtgUdTSRQ=
+golang.org/x/exp/typeparams v0.0.0-20231108232855-2478ac86f678 h1:1P7xPZEwZMoBoz0Yze5Nx2/4pxj6nw9ZqHWXqP0iRgQ=
+golang.org/x/exp/typeparams v0.0.0-20231108232855-2478ac86f678/go.mod h1:AbB0pIl9nAr9wVwH+Z2ZpaocVmF5I4GyWCDIsVjR0bk=
+golang.org/x/mod v0.31.0 h1:HaW9xtz0+kOcWKwli0ZXy79Ix+UW/vOfmWI5QVd2tgI=
+golang.org/x/mod v0.31.0/go.mod h1:43JraMp9cGx1Rx3AqioxrbrhNsLl2l/iNAvuBkrezpg=
+golang.org/x/sync v0.19.0 h1:vV+1eWNmZ5geRlYjzm2adRgW2/mcpevXNg50YZtPCE4=
+golang.org/x/sync v0.19.0/go.mod h1:9KTHXmSnoGruLpwFjVSX0lNNA75CykiMECbovNTZqGI=
+golang.org/x/tools v0.40.1-0.20260108161641-ca281cf95054 h1:CHVDrNHx9ZoOrNN9kKWYIbT5Rj+WF2rlwPkhbQQ5V4U=
+golang.org/x/tools v0.40.1-0.20260108161641-ca281cf95054/go.mod h1:Ik/tzLRlbscWpqqMRjyWYDisX8bG13FrdXp3o4Sr9lc=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
 gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+honnef.co/go/tools v0.7.0 h1:w6WUp1VbkqPEgLz4rkBzH/CSU6HkoqNLp6GstyTx3lU=
+honnef.co/go/tools v0.7.0/go.mod h1:pm29oPxeP3P82ISxZDgIYeOaf9ta6Pi0EWvCFoLG2vc=

internal/cicontext/context.go

@@ -1,12 +1,16 @@
 package cicontext
 
-import "strings"
+import (
+	"fmt"
+	"strings"
+)
 
 // Context holds the simulated CI execution environment used for context-aware
 // pipeline evaluation (rules:if:, only:, except:, workflow:rules:).
 // Variables are keyed by their name without the leading $.
 type Context struct {
 	Vars   map[string]string
+	pinned map[string]bool // vars set via --var or shortcuts; never overwritten by Inject
 }
 
 // New builds a Context from high-level shortcut values and optional KEY=VALUE
@@ -17,46 +21,55 @@ type Context struct {
 // preserving the existing linting behaviour when no context flags are given.
 //
 // Override priority (highest wins): extraVars > branch/tag/source shortcuts.
+// Both shortcut-derived and extraVar variables are pinned — they will not be
+// overwritten by Inject (used for pipeline-level and workflow-rule variables).
 func New(branch, tag, source string, extraVars []string) *Context {
 	if branch == "" && tag == "" && source == "" && len(extraVars) == 0 {
 		return &Context{}
 	}
 
 	vars := make(map[string]string)
+	pinned := make(map[string]bool)
+
+	pin := func(k, v string) {
+		vars[k] = v
+		pinned[k] = true
+	}
 
 	if branch != "" {
-		vars["CI_COMMIT_BRANCH"] = branch
-		vars["CI_COMMIT_REF_NAME"] = branch
-		vars["CI_COMMIT_REF_SLUG"] = slugify(branch)
+		pin("CI_COMMIT_BRANCH", branch)
+		pin("CI_COMMIT_REF_NAME", branch)
+		pin("CI_COMMIT_REF_SLUG", slugify(branch))
 		if source == "" {
 			source = "push"
 		}
 	}
 	if tag != "" {
-		vars["CI_COMMIT_TAG"] = tag
-		vars["CI_COMMIT_REF_NAME"] = tag
-		vars["CI_COMMIT_REF_SLUG"] = slugify(tag)
-		delete(vars, "CI_COMMIT_BRANCH") // tag pushes have no branch variable
+		pin("CI_COMMIT_TAG", tag)
+		pin("CI_COMMIT_REF_NAME", tag)
+		pin("CI_COMMIT_REF_SLUG", slugify(tag))
+		delete(vars, "CI_COMMIT_BRANCH")
+		delete(pinned, "CI_COMMIT_BRANCH")
 		if source == "" {
 			source = "push"
 		}
 	}
 	if source != "" {
-		vars["CI_PIPELINE_SOURCE"] = source
+		pin("CI_PIPELINE_SOURCE", source)
 	}
 	if _, ok := vars["CI_DEFAULT_BRANCH"]; !ok {
 		vars["CI_DEFAULT_BRANCH"] = "main"
 	}
 
-	// KEY=VALUE overrides win over shortcuts.
+	// KEY=VALUE overrides win over shortcuts and everything else.
 	for _, kv := range extraVars {
 		k, v, ok := strings.Cut(kv, "=")
 		if ok {
-			vars[k] = v
+			pin(k, v)
 		}
 	}
 
-	return &Context{Vars: vars}
+	return &Context{Vars: vars, pinned: pinned}
 }
 
 // IsEmpty reports whether no variables have been set (no context flags given).
@@ -73,6 +86,21 @@ func (c *Context) Get(key string) string {
 	return c.Vars[key]
 }
 
+// Inject sets key=value only if key is not already pinned (i.e. not set via
+// --branch / --tag / --source / --var). Used to inject pipeline-level variable
+// defaults and workflow-rule variables without overriding explicit user input.
+// Calling Inject in order from lowest-priority to highest-priority source
+// ensures later calls win over earlier ones.
+func (c *Context) Inject(key, value string) {
+	if c.pinned[key] {
+		return
+	}
+	if c.Vars == nil {
+		c.Vars = make(map[string]string)
+	}
+	c.Vars[key] = value
+}
+
 // Summary returns a short human-readable description of the context for CLI output.
 func (c *Context) Summary() string {
 	if c.IsEmpty() {
@@ -90,6 +118,133 @@ func (c *Context) Summary() string {
 	return strings.Join(parts, ", ")
 }
 
+// ExtractStringVars converts a map[string]any variable block (as used by
+// Pipeline.Variables and Rule.Variables) to a flat map[string]string.
+// Plain string values are used directly. Extended {value: ...} map form uses
+// the "value" key. Scalar non-string values (bool, int, float64) are
+// converted to their string representation, matching GitLab's own behaviour
+// where all CI variable values are strings.
+func ExtractStringVars(m map[string]any) map[string]string {
+	if len(m) == 0 {
+		return nil
+	}
+	out := make(map[string]string, len(m))
+	for k, v := range m {
+		if s, ok := ScalarString(v); ok {
+			out[k] = s
+		}
+	}
+	return out
+}
+
+// ScalarString converts a YAML-decoded CI variable value to its string
+// representation. Handles plain scalars and the extended {value: ...} map
+// form. Returns (s, true) on success, ("", false) for unrecognised forms.
+func ScalarString(v any) (string, bool) {
+	switch val := v.(type) {
+	case string:
+		return val, true
+	case bool:
+		return fmt.Sprintf("%t", val), true
+	case int:
+		return fmt.Sprintf("%d", val), true
+	case float64:
+		return fmt.Sprintf("%g", val), true
+	case map[string]any:
+		inner, ok := val["value"]
+		if !ok {
+			return "", false
+		}
+		return ScalarString(inner)
+	}
+	return "", false
+}
+
+// ExpandVars expands $VAR and ${VAR} references within every value in
+// ctx.Vars, using the same map as the expansion source. Iteration repeats
+// (up to 10 passes) so transitive chains like A=$B, B=$C resolve fully.
+// Variables that form circular references are left as-is after the limit.
+func (c *Context) ExpandVars() {
+	if c == nil || len(c.Vars) == 0 {
+		return
+	}
+	for range 10 {
+		changed := false
+		for k, v := range c.Vars {
+			expanded := expandVarRefs(v, c.Vars)
+			if expanded != v {
+				c.Vars[k] = expanded
+				changed = true
+			}
+		}
+		if !changed {
+			return
+		}
+	}
+}
+
+// expandVarRefs replaces $VAR and ${VAR} occurrences in s with their values
+// from vars. Unknown variables are left unchanged.
+func expandVarRefs(s string, vars map[string]string) string {
+	if !strings.Contains(s, "$") {
+		return s
+	}
+	var sb strings.Builder
+	i := 0
+	for i < len(s) {
+		if s[i] != '$' {
+			sb.WriteByte(s[i])
+			i++
+			continue
+		}
+		i++ // consume '$'
+		if i >= len(s) {
+			sb.WriteByte('$')
+			break
+		}
+		if s[i] == '{' {
+			i++ // consume '{'
+			j := i
+			for j < len(s) && isIdentByte(s[j]) {
+				j++
+			}
+			if j < len(s) && s[j] == '}' {
+				name := s[i:j]
+				if val, ok := vars[name]; ok {
+					sb.WriteString(val)
+				} else {
+					sb.WriteString("${")
+					sb.WriteString(name)
+					sb.WriteByte('}')
+				}
+				i = j + 1
+			} else {
+				// Malformed ${…} — emit literally
+				sb.WriteString("${")
+				i = j
+			}
+		} else {
+			j := i
+			for j < len(s) && isIdentByte(s[j]) {
+				j++
+			}
+			if j > i {
+				name := s[i:j]
+				if val, ok := vars[name]; ok {
+					sb.WriteString(val)
+				} else {
+					sb.WriteByte('$')
+					sb.WriteString(name)
+				}
+				i = j
+			} else {
+				sb.WriteByte('$')
+			}
+		}
+	}
+	return sb.String()
+}
+
 // slugify converts a ref name to its GitLab slug form:
 // lowercased, non-alphanumeric characters replaced with '-', leading/trailing '-' removed.
 func slugify(s string) string {

internal/cicontext/eval.go

@@ -9,21 +9,35 @@ import (
 // variable resolver.
 //
 // Supported:
-//   - Variable references: $VAR_NAME
+//   - Variable references: $VAR_NAME or ${VAR_NAME}
 //   - String literals:     "value" or 'value'
 //   - Null keyword:        null
-//   - Comparison:          == != =~ !~
+//   - Comparison:          == != =~ !~  (single = is accepted as == for user convenience)
 //   - Boolean:             && || !
 //   - Grouping:            ( )
+//   - Regex flags:         /pattern/i (case-insensitive), /pattern/m, /pattern/s
+//   - Multi-line:          newlines between tokens are treated as whitespace
+//   - Variable regex RHS:  $VAR =~ $PATTERN when $PATTERN holds a /regex/ string
 //
 // Regex patterns use Go's regexp syntax, which covers the common RE2 subset
 // used by GitLab CI. Unsupported or unparseable expressions fall back to true
 // (permissive) so the linter never silently drops jobs it cannot evaluate.
 func EvalIf(expr string, vars func(string) string) bool {
+	return evalIf(expr, vars, true)
+}
+
+// EvalIfStrict is like EvalIf but returns false (instead of true) when the
+// expression cannot be fully parsed. Use for workflow:rules: evaluation where
+// a failed parse should skip to the next rule rather than matching everything.
+func EvalIfStrict(expr string, vars func(string) string) bool {
+	return evalIf(expr, vars, false)
+}
+
+func evalIf(expr string, vars func(string) string, permissive bool) bool {
 	p := &exprParser{s: strings.TrimSpace(expr), vars: vars}
 	result, ok := p.parseOr()
 	if !ok || p.pos < len(p.s) {
-		return true // unparseable → permissive
+		return permissive
 	}
 	return result
 }
@@ -56,8 +70,13 @@ func (p *exprParser) consume(tok string) bool {
 }
 
 func (p *exprParser) skipWS() {
-	for p.pos < len(p.s) && (p.s[p.pos] == ' ' || p.s[p.pos] == '\t') {
+	for p.pos < len(p.s) {
+		b := p.s[p.pos]
+		if b == ' ' || b == '\t' || b == '\n' || b == '\r' {
 			p.pos++
+			continue
+		}
+		break
 	}
 }
 
@@ -67,11 +86,11 @@ func (p *exprParser) skipWS() {
 //   and_expr   → not_expr ( '&&' not_expr )*
 //   not_expr   → '!' not_expr | primary
 //   primary    → '(' or_expr ')' | comparison
-//   comparison → value ( op value | regex_op regex )? | value
-//   value      → '$' ident | '"' … '"' | "'" … "'" | 'null'
+//   comparison → value ( op value | regex_op regex_rhs )?
+//   value      → '$' '{' ident '}' | '$' ident | '"' … '"' | "'" … "'" | 'null'
 //   op         → '==' | '!='
 //   regex_op   → '=~' | '!~'
-//   regex      → '/' … '/'
+//   regex_rhs  → '/' … '/' flags? | '$' ident (where ident value is '/…/flags')
 
 func (p *exprParser) parseOr() (bool, bool) {
 	left, ok := p.parseAnd()
@@ -165,8 +184,11 @@ func (p *exprParser) parseComparison() (bool, bool) {
 
 	case p.consume("=~"):
 		p.skipWS()
-		pat, ok := p.parseRegexLiteral()
-		if !ok {
+		pat, patOk, permissive := p.parseRegexRHS()
+		if permissive {
+			return true, true
+		}
+		if !patOk {
 			return false, false
 		}
 		re, err := regexp.Compile(pat)
@@ -177,8 +199,11 @@ func (p *exprParser) parseComparison() (bool, bool) {
 
 	case p.consume("!~"):
 		p.skipWS()
-		pat, ok := p.parseRegexLiteral()
-		if !ok {
+		pat, patOk, permissive := p.parseRegexRHS()
+		if permissive {
+			return true, true
+		}
+		if !patOk {
 			return false, false
 		}
 		re, err := regexp.Compile(pat)
@@ -186,19 +211,66 @@ func (p *exprParser) parseComparison() (bool, bool) {
 			return true, true // bad pattern → permissive
 		}
 		return !re.MatchString(leftStr), true
+
+	// Single = not followed by = or ~ — accepted as == (common user mistake;
+	// GitLab CI only supports == but = is frequently written by accident).
+	case p.peek() == '=' && !p.startsWith("==") && !p.startsWith("=~"):
+		p.pos++ // consume '='
+		p.skipWS()
+		rightStr, ok := p.parseValue()
+		if !ok {
+			return false, false
+		}
+		return leftStr == rightStr, true
 	}
 
 	// No operator: variable is truthy when non-empty (defined and non-null).
 	return leftStr != "", true
 }
 
-// parseValue reads $VAR, "string", 'string', or null.
-// null and undefined variables both produce an empty string.
+// parseRegexRHS parses the right-hand side of =~ / !~ operators.
+// Returns (pattern, ok, permissive):
+//   - /regex/flags literal  → (pattern, true, false)
+//   - $VAR whose value is /regex/flags → (pattern, true, false)
+//   - $VAR whose value is empty or not a /regex/ → ("", false, true) — caller uses permissive true
+//   - parse error → ("", false, false)
+func (p *exprParser) parseRegexRHS() (pat string, ok bool, permissive bool) {
+	if p.peek() == '/' {
+		pat, ok = p.parseRegexLiteral()
+		return pat, ok, false
+	}
+	if p.peek() == '$' {
+		varVal, varOk := p.parseValue()
+		if !varOk {
+			return "", false, false
+		}
+		pat, ok = extractRegexFromString(varVal)
+		if !ok {
+			return "", false, true // variable is not a /regex/ value → permissive
+		}
+		return pat, true, false
+	}
+	return "", false, false
+}
+
+// parseValue reads $VAR, ${VAR}, "string", 'string', null, true, false, or an
+// integer literal. null and undefined variables both produce an empty string.
+// true/false and integers produce their string representations (GitLab CI
+// compares all values as strings).
 func (p *exprParser) parseValue() (string, bool) {
 	p.skipWS()
 
 	if p.peek() == '$' {
 		p.pos++ // consume '$'
+		if p.peek() == '{' {
+			p.pos++ // consume '{'
+			name := p.parseIdent()
+			if name == "" || p.peek() != '}' {
+				return "", false
+			}
+			p.pos++ // consume '}'
+			return p.vars(name), true
+		}
 		name := p.parseIdent()
 		if name == "" {
 			return "", false
@@ -206,12 +278,18 @@ func (p *exprParser) parseValue() (string, bool) {
 		return p.vars(name), true
 	}
 
-	// null keyword — must not be a prefix of a longer identifier.
-	if p.startsWith("null") {
-		end := p.pos + 4
+	// Keywords and string literals must not be prefixes of longer identifiers.
+	for _, kw := range []struct{ tok, val string }{
+		{"null", ""},
+		{"true", "true"},
+		{"false", "false"},
+	} {
+		if p.startsWith(kw.tok) {
+			end := p.pos + len(kw.tok)
 			if end >= len(p.s) || !isIdentByte(p.s[end]) {
-			p.pos += 4
-			return "", true // null → empty string
+				p.pos += len(kw.tok)
+				return kw.val, true
+			}
 		}
 	}
 
@@ -219,6 +297,15 @@ func (p *exprParser) parseValue() (string, bool) {
 		return p.parseStringLiteral()
 	}
 
+	// Integer literal — returned as its decimal string for string comparison.
+	if p.peek() >= '0' && p.peek() <= '9' {
+		start := p.pos
+		for p.pos < len(p.s) && p.s[p.pos] >= '0' && p.s[p.pos] <= '9' {
+			p.pos++
+		}
+		return p.s[start:p.pos], true
+	}
+
 	return "", false
 }
 
@@ -261,7 +348,8 @@ func (p *exprParser) parseRegexLiteral() (string, bool) {
 		b := p.s[p.pos]
 		if b == '/' {
 			p.pos++ // consume closing '/'
-			return sb.String(), true
+			flags := p.parseRegexFlags()
+			return applyRegexFlags(flags, sb.String()), true
 		}
 		if b == '\\' && p.pos+1 < len(p.s) {
 			p.pos++
@@ -275,6 +363,68 @@ func (p *exprParser) parseRegexLiteral() (string, bool) {
 	return "", false // unterminated regex
 }
 
+// parseRegexFlags reads zero or more regex flag letters (i, m, s) after the
+// closing '/'. Unknown letters are consumed but ignored.
+func (p *exprParser) parseRegexFlags() string {
+	start := p.pos
+	for p.pos < len(p.s) && isIdentByte(p.s[p.pos]) {
+		p.pos++
+	}
+	return p.s[start:p.pos]
+}
+
+// applyRegexFlags prepends Go regexp flag groups to pattern (e.g. (?i) for 'i').
+// Unknown flags are silently ignored.
+func applyRegexFlags(flags, pattern string) string {
+	if flags == "" {
+		return pattern
+	}
+	var prefix strings.Builder
+	for _, f := range flags {
+		switch f {
+		case 'i':
+			prefix.WriteString("(?i)")
+		case 'm':
+			prefix.WriteString("(?m)")
+		case 's':
+			prefix.WriteString("(?s)")
+		}
+	}
+	return prefix.String() + pattern
+}
+
+// extractRegexFromString parses a /pattern/flags string (typically from a CI
+// variable) and returns a Go regexp pattern with flags applied.
+func extractRegexFromString(s string) (string, bool) {
+	s = strings.TrimSpace(s)
+	if len(s) == 0 || s[0] != '/' {
+		return "", false
+	}
+	var sb strings.Builder
+	i := 1
+	for i < len(s) {
+		b := s[i]
+		if b == '/' {
+			i++ // past closing '/'
+			var flags strings.Builder
+			for i < len(s) && isIdentByte(s[i]) {
+				flags.WriteByte(s[i])
+				i++
+			}
+			return applyRegexFlags(flags.String(), sb.String()), true
+		}
+		if b == '\\' && i+1 < len(s) {
+			i++
+			sb.WriteByte('\\')
+			sb.WriteByte(s[i])
+		} else {
+			sb.WriteByte(b)
+		}
+		i++
+	}
+	return "", false // unterminated
+}
+
 func isIdentByte(b byte) bool {
 	return (b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z') || (b >= '0' && b <= '9') || b == '_'
 }

internal/cicontext/eval_test.go

@@ -9,6 +9,10 @@ func TestEvalIf(t *testing.T) {
 			"CI_COMMIT_TAG":     "",
 			"CI_PIPELINE_SOURCE": "push",
 			"DEPLOY_ENV":        "staging",
+			"BRANCH_PATTERN":    "/^dev/",
+			"BRANCH_PATTERN_CI": "/^DEV/i",
+			"EMPTY_PATTERN":     "",
+			"PLAIN_PATTERN":     "develop",
 		}
 		return m[key]
 	}
@@ -69,9 +73,59 @@ func TestEvalIf(t *testing.T) {
 		{"extra spaces", `  $CI_COMMIT_BRANCH  ==  "develop"  `, true},
 		{"tabs", "$CI_COMMIT_BRANCH\t==\t\"develop\"", true},
 
+		// ── Multi-line expressions (newlines between tokens) ──────────────────
+		{"multiline or true", "$CI_COMMIT_BRANCH == \"develop\" ||\n$CI_COMMIT_TAG != null", true},
+		{"multiline or false", "$CI_COMMIT_BRANCH == \"main\" ||\n$CI_COMMIT_TAG != null", false},
+		{"multiline and true", "$CI_COMMIT_BRANCH == \"develop\" &&\n$CI_PIPELINE_SOURCE == \"push\"", true},
+		{"multiline and false", "$CI_COMMIT_BRANCH == \"main\" &&\n$CI_PIPELINE_SOURCE == \"push\"", false},
+		{"multiline with crlf", "$CI_COMMIT_BRANCH == \"develop\" ||\r\n$CI_COMMIT_TAG != null", true},
+
+		// ── ${VAR} curly-brace syntax ─────────────────────────────────────────
+		{"curly var eq match", `${CI_COMMIT_BRANCH} == "develop"`, true},
+		{"curly var eq no match", `${CI_COMMIT_BRANCH} == "main"`, false},
+		{"curly var truthiness", `${CI_COMMIT_BRANCH}`, true},
+		{"curly var falsy", `${CI_COMMIT_TAG}`, false},
+		{"curly var neq null", `${CI_COMMIT_BRANCH} != null`, true},
+		{"curly mixed", `${CI_COMMIT_BRANCH} == "develop" && $CI_PIPELINE_SOURCE == "push"`, true},
+
+		// ── Regex flags (/pattern/i etc.) ─────────────────────────────────────
+		{"regex flag i match", `$CI_COMMIT_BRANCH =~ /^DEV/i`, true},
+		{"regex flag i no match", `$CI_COMMIT_BRANCH =~ /^MAIN/i`, false},
+		{"regex flag i not match", `$CI_COMMIT_BRANCH !~ /^MAIN/i`, true},
+		{"regex no flag case sensitive", `$CI_COMMIT_BRANCH =~ /^DEV/`, false},
+		{"regex flag i version tag", `$CI_PIPELINE_SOURCE =~ /^PUSH$/i`, true},
+
+		// ── Variable on right side of =~ ──────────────────────────────────────
+		{"var regex rhs match", `$CI_COMMIT_BRANCH =~ $BRANCH_PATTERN`, true},
+		{"var regex rhs no match", `$CI_PIPELINE_SOURCE =~ $BRANCH_PATTERN`, false},
+		{"var regex rhs ci flag match", `$CI_COMMIT_BRANCH =~ $BRANCH_PATTERN_CI`, true},
+		{"var regex rhs empty permissive", `$CI_COMMIT_BRANCH =~ $EMPTY_PATTERN`, true},
+		{"var regex rhs plain permissive", `$CI_COMMIT_BRANCH =~ $PLAIN_PATTERN`, true},
+		{"var regex rhs not match", `$CI_COMMIT_BRANCH !~ $BRANCH_PATTERN`, false},
+
+		// ── Bare true/false keywords ─────────────────────────────────────────
+		// GitLab CI treats true/false as the string values "true"/"false".
+		{"bare true match", `$CI_PIPELINE_SOURCE == true`, false},       // "push" != "true"
+		{"bare false match", `$CI_COMMIT_TAG == false`, false},           // "" != "false"
+		{"bare true var set to true", `$DEPLOY_ENV == true`, false},      // "staging" != "true"
+		{"bare false neq", `$CI_COMMIT_BRANCH != false`, true},           // "develop" != "false"
+		{"bare true in compound", `$CI_COMMIT_BRANCH != null && $CI_COMMIT_TAG == false`, false},
+
+		// ── Integer literals ──────────────────────────────────────────────────
+		// Compared as decimal strings (GitLab CI converts integers to strings).
+		{"int eq match", `$CI_PIPELINE_SOURCE != 0`, true},  // "push" != "0"
+		{"int eq no match", `$CI_COMMIT_TAG == 0`, false},    // "" != "0"
+		{"int in compound", `$CI_COMMIT_BRANCH != null && $CI_COMMIT_BRANCH != 0`, true},
+
 		// ── Permissive fallback ───────────────────────────────────────────────
 		{"unparseable returns true", `this is not valid syntax %%%`, true},
 		{"empty expr returns true", ``, true},
+
+		// ── Single = as alias for == ──────────────────────────────────────────
+		{"single eq match", `$CI_COMMIT_BRANCH = "develop"`, true},
+		{"single eq no match", `$CI_COMMIT_BRANCH = "main"`, false},
+		{"single eq in compound", `$CI_COMMIT_BRANCH = "develop" && $CI_PIPELINE_SOURCE = "push"`, true},
+		{"single eq compound false", `$CI_COMMIT_BRANCH = "main" && $CI_PIPELINE_SOURCE = "push"`, false},
 	}
 
 	for _, tc := range tests {
@@ -83,3 +137,48 @@ func TestEvalIf(t *testing.T) {
 		})
 	}
 }
+
+func TestEvalIfStrict(t *testing.T) {
+	vars := func(key string) string {
+		m := map[string]string{
+			"CI_COMMIT_BRANCH":   "develop",
+			"CI_PIPELINE_SOURCE": "push",
+			"WORKFLOW":           "",
+		}
+		return m[key]
+	}
+
+	tests := []struct {
+		name string
+		expr string
+		want bool
+	}{
+		// Parseable expressions behave identically to EvalIf.
+		{"parseable match", `$CI_COMMIT_BRANCH == "develop"`, true},
+		{"parseable no match", `$CI_COMMIT_BRANCH == "main"`, false},
+		{"single eq match", `$CI_COMMIT_BRANCH = "develop"`, true},
+		// Empty expression: ruleIfMatchesStrict handles the empty→true case
+		// before calling EvalIfStrict, so empty falls through to false here.
+		{"empty expr", ``, false},
+
+		// Unparseable expressions return false (strict) instead of true (permissive).
+		{"unparseable returns false", `this is not valid syntax %%%`, false},
+
+		// The key workflow-rule scenario: a complex condition with an
+		// unevaluable sub-expression should not match (strict=false) so that
+		// later workflow rules can be evaluated.
+		{"workflow rule complex no match", `$WORKFLOW = "gitflow" && $CI_PIPELINE_SOURCE == /(push|web)/`, false},
+
+		// Compound with a bad second operand: strict returns false.
+		{"and with bad rhs strict false", `$CI_COMMIT_BRANCH == "develop" && !(((`, false},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			got := EvalIfStrict(tc.expr, vars)
+			if got != tc.want {
+				t.Errorf("EvalIfStrict(%q) = %v, want %v", tc.expr, got, tc.want)
+			}
+		})
+	}
+}

internal/cicontext/reachability.go

@@ -28,26 +28,34 @@ func (s JobState) String() string {
 	}
 }
 
-// EvalWorkflow returns false when the pipeline's workflow:rules block would
-// prevent any pipeline from starting in the given context.
-// Returns true when ctx is empty, when there is no workflow block, or when no
-// rule is configured.
-func EvalWorkflow(p *model.Pipeline, ctx *Context) bool {
+// EvalWorkflow evaluates the pipeline's workflow:rules block against ctx.
+// Returns (runs, ruleVars):
+//   - runs=false means the pipeline would not start for this context.
+//   - ruleVars holds any variables: defined on the matching rule; inject these
+//     into the context so job rules can reference them.
+//
+// Returns (true, nil) when ctx is empty, when there is no workflow block, or
+// when no rules are configured.
+func EvalWorkflow(p *model.Pipeline, ctx *Context) (bool, map[string]string) {
 	if ctx.IsEmpty() || p.Workflow == nil || len(p.Workflow.Rules) == 0 {
-		return true
+		return true, nil
 	}
 	vars := ctx.Get
 	for _, rule := range p.Workflow.Rules {
-		if !ruleIfMatches(rule.If, vars) {
+		// Workflow rules use strict evaluation: an unparseable condition is
+		// treated as no-match so later rules (with valid conditions or a
+		// bare when:) are reached. Permissive-true would cause an early rule
+		// with a complex/invalid condition to block all subsequent rules.
+		if !ruleIfMatchesStrict(rule.If, vars) {
 			continue
 		}
 		when := rule.When
 		if when == "" {
 			when = "always"
 		}
-		return when != "never"
+		return when != "never", ExtractStringVars(rule.Variables)
 	}
-	return false // no rule matched → pipeline does not run
+	return false, nil // no rule matched → pipeline does not run
 }
 
 // EvalJob returns the effective JobState for job in the given context.
@@ -90,6 +98,13 @@ func ruleIfMatches(ifExpr string, vars func(string) string) bool {
 	return EvalIf(ifExpr, vars)
 }
 
+func ruleIfMatchesStrict(ifExpr string, vars func(string) string) bool {
+	if ifExpr == "" {
+		return true // no if: condition → rule always matches
+	}
+	return EvalIfStrict(ifExpr, vars)
+}
+
 func whenToState(when string) JobState {
 	switch when {
 	case "never":

internal/cicontext/reachability_test.go

@@ -0,0 +1,243 @@
+package cicontext
+
+import (
+	"testing"
+
+	"git.k3nny.fr/glint/internal/model"
+)
+
+func TestEvalWorkflow(t *testing.T) {
+	makePipeline := func(rules []model.Rule) *model.Pipeline {
+		return &model.Pipeline{Workflow: &model.Workflow{Rules: rules}}
+	}
+
+	tests := []struct {
+		name     string
+		rules    []model.Rule
+		branch   string
+		wantRuns bool
+		wantVars map[string]string
+	}{
+		{
+			name:     "no workflow block",
+			rules:    nil,
+			branch:   "main",
+			wantRuns: true,
+			wantVars: nil,
+		},
+		{
+			name: "matching rule runs always",
+			rules: []model.Rule{
+				{If: `$CI_COMMIT_BRANCH == "main"`, When: "always"},
+			},
+			branch:   "main",
+			wantRuns: true,
+		},
+		{
+			name: "matching rule when never",
+			rules: []model.Rule{
+				{If: `$CI_COMMIT_BRANCH == "main"`, When: "never"},
+			},
+			branch:   "main",
+			wantRuns: false,
+		},
+		{
+			name: "no rule matched",
+			rules: []model.Rule{
+				{If: `$CI_COMMIT_BRANCH == "main"`},
+			},
+			branch:   "develop",
+			wantRuns: false,
+		},
+		{
+			name: "matching rule with variables",
+			rules: []model.Rule{
+				{
+					If:   `$CI_COMMIT_BRANCH == "main"`,
+					When: "always",
+					Variables: map[string]any{
+						"DEPLOY_TARGET": "production",
+						"ENVIRONMENT":   "prod",
+					},
+				},
+				{When: "always"},
+			},
+			branch:   "main",
+			wantRuns: true,
+			wantVars: map[string]string{
+				"DEPLOY_TARGET": "production",
+				"ENVIRONMENT":   "prod",
+			},
+		},
+		{
+			name: "fallback rule with different variables",
+			rules: []model.Rule{
+				{If: `$CI_COMMIT_BRANCH == "main"`, Variables: map[string]any{"DEPLOY_TARGET": "production"}},
+				{When: "always", Variables: map[string]any{"DEPLOY_TARGET": "staging"}},
+			},
+			branch:   "develop",
+			wantRuns: true,
+			wantVars: map[string]string{"DEPLOY_TARGET": "staging"},
+		},
+		{
+			name: "empty context always runs",
+			rules: []model.Rule{
+				{If: `$CI_COMMIT_BRANCH == "main"`, When: "never"},
+			},
+			branch:   "", // no context
+			wantRuns: true,
+			wantVars: nil,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			var p *model.Pipeline
+			if tc.rules == nil {
+				p = &model.Pipeline{}
+			} else {
+				p = makePipeline(tc.rules)
+			}
+			ctx := New(tc.branch, "", "", nil)
+			runs, vars := EvalWorkflow(p, ctx)
+			if runs != tc.wantRuns {
+				t.Errorf("EvalWorkflow runs = %v, want %v", runs, tc.wantRuns)
+			}
+			for k, want := range tc.wantVars {
+				if got := vars[k]; got != want {
+					t.Errorf("EvalWorkflow vars[%q] = %q, want %q", k, got, want)
+				}
+			}
+			if len(vars) != len(tc.wantVars) {
+				t.Errorf("EvalWorkflow returned %d vars, want %d; got %v", len(vars), len(tc.wantVars), vars)
+			}
+		})
+	}
+}
+
+func TestContextInject(t *testing.T) {
+	t.Run("inject does not overwrite pinned var", func(t *testing.T) {
+		ctx := New("main", "", "", []string{"DEPLOY_TARGET=override"})
+		ctx.Inject("DEPLOY_TARGET", "workflow-value")
+		if got := ctx.Get("DEPLOY_TARGET"); got != "override" {
+			t.Errorf("Inject overwrote pinned var: got %q, want %q", got, "override")
+		}
+	})
+	t.Run("inject does not overwrite shortcut var", func(t *testing.T) {
+		ctx := New("main", "", "", nil)
+		ctx.Inject("CI_COMMIT_BRANCH", "other")
+		if got := ctx.Get("CI_COMMIT_BRANCH"); got != "main" {
+			t.Errorf("Inject overwrote shortcut var: got %q, want %q", got, "main")
+		}
+	})
+	t.Run("inject sets new variable", func(t *testing.T) {
+		ctx := New("main", "", "", nil)
+		ctx.Inject("DEPLOY_TARGET", "production")
+		if got := ctx.Get("DEPLOY_TARGET"); got != "production" {
+			t.Errorf("Inject did not set variable: got %q", got)
+		}
+	})
+	t.Run("inject later call overrides earlier call", func(t *testing.T) {
+		ctx := New("main", "", "", nil)
+		ctx.Inject("DEPLOY_TARGET", "pipeline-default")
+		ctx.Inject("DEPLOY_TARGET", "workflow-override")
+		if got := ctx.Get("DEPLOY_TARGET"); got != "workflow-override" {
+			t.Errorf("second Inject did not win: got %q, want %q", got, "workflow-override")
+		}
+	})
+}
+
+func TestExtractStringVars(t *testing.T) {
+	tests := []struct {
+		name string
+		in   map[string]any
+		want map[string]string
+	}{
+		{
+			name: "plain strings",
+			in:   map[string]any{"A": "hello", "B": "world"},
+			want: map[string]string{"A": "hello", "B": "world"},
+		},
+		{
+			name: "extended value form",
+			in: map[string]any{
+				"KEY": map[string]any{"value": "extended", "description": "some desc"},
+			},
+			want: map[string]string{"KEY": "extended"},
+		},
+		{
+			name: "mixed forms",
+			in: map[string]any{
+				"PLAIN":   "str",
+				"COMPLEX": map[string]any{"value": "val"},
+			},
+			want: map[string]string{"PLAIN": "str", "COMPLEX": "val"},
+		},
+		{
+			name: "nil map",
+			in:   nil,
+			want: nil,
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			got := ExtractStringVars(tc.in)
+			for k, want := range tc.want {
+				if got[k] != want {
+					t.Errorf("ExtractStringVars[%q] = %q, want %q", k, got[k], want)
+				}
+			}
+			if len(got) != len(tc.want) {
+				t.Errorf("ExtractStringVars returned %d entries, want %d", len(got), len(tc.want))
+			}
+		})
+	}
+}
+
+// TestWorkflowVarsJobEval verifies the end-to-end flow: workflow rule injects
+// DEPLOY_TARGET, which is then used in a job's rules:if: expression.
+func TestWorkflowVarsJobEval(t *testing.T) {
+	rules := []model.Rule{
+		{If: `$CI_COMMIT_BRANCH == "main"`, Variables: map[string]any{"DEPLOY_TARGET": "production"}},
+		{When: "always", Variables: map[string]any{"DEPLOY_TARGET": "staging"}},
+	}
+	p := &model.Pipeline{
+		Workflow: &model.Workflow{Rules: rules},
+		Jobs: map[string]model.Job{
+			"deploy-prod": {
+				Rules: []model.Rule{
+					{If: `$DEPLOY_TARGET == "production"`, When: "on_success"},
+					{When: "never"},
+				},
+			},
+			"deploy-staging": {
+				Rules: []model.Rule{
+					{If: `$DEPLOY_TARGET == "staging"`, When: "on_success"},
+					{When: "never"},
+				},
+			},
+		},
+	}
+
+	for _, tc := range []struct {
+		branch      string
+		wantProd    JobState
+		wantStaging JobState
+	}{
+		{"main", JobActive, JobSkipped},
+		{"develop", JobSkipped, JobActive},
+	} {
+		ctx := New(tc.branch, "", "", nil)
+		_, ruleVars := EvalWorkflow(p, ctx)
+		for k, v := range ruleVars {
+			ctx.Inject(k, v)
+		}
+		if got := EvalJob(p.Jobs["deploy-prod"], ctx); got != tc.wantProd {
+			t.Errorf("branch=%q deploy-prod = %v, want %v", tc.branch, got, tc.wantProd)
+		}
+		if got := EvalJob(p.Jobs["deploy-staging"], ctx); got != tc.wantStaging {
+			t.Errorf("branch=%q deploy-staging = %v, want %v", tc.branch, got, tc.wantStaging)
+		}
+	}
+}

internal/config/config.go

@@ -0,0 +1,75 @@
+package config
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"gopkg.in/yaml.v3"
+)
+
+// Filename is the name of the project-level glint configuration file.
+const Filename = ".glint.yml"
+
+// Config holds project-level glint configuration loaded from .glint.yml.
+type Config struct {
+	// Ignore lists rule IDs to suppress entirely (e.g. ["GL007", "GL032"]).
+	Ignore []string `yaml:"ignore"`
+
+	// Severity maps rule IDs to overridden severity levels.
+	// Valid values: "error", "warning", "ignore".
+	// "ignore" is equivalent to listing the rule in Ignore.
+	Severity map[string]string `yaml:"severity"`
+
+	// Stages lists additional stage names that are considered valid for this
+	// project, beyond what is declared in the pipeline's own stages: block.
+	// Jobs in these stages are not flagged by GL004.
+	Stages []string `yaml:"stages"`
+
+	// Token is a default GitLab personal access token used when neither the
+	// --token flag nor GITLAB_TOKEN (/ CI_JOB_TOKEN / GITLAB_PRIVATE_TOKEN)
+	// environment variables are set.
+	Token string `yaml:"token"`
+
+	// URL is the default GitLab instance URL. Overridden by --gitlab-url and
+	// the CI_SERVER_URL / GITLAB_URL environment variables.
+	URL string `yaml:"url"`
+
+	// CacheDir is the default directory for caching fetched remote includes.
+	// Overridden by the --cache-dir flag.
+	CacheDir string `yaml:"cache_dir"`
+}
+
+// Load searches for a .glint.yml file starting from dir and walking up toward
+// the filesystem root. The walk stops at the first .git directory found (the
+// repository root) or at the filesystem root. Returns an empty Config (and no
+// error) when no config file is found.
+func Load(dir string) (Config, error) {
+	dir = filepath.Clean(dir)
+	for {
+		candidate := filepath.Join(dir, Filename)
+		data, err := os.ReadFile(candidate)
+		if err == nil {
+			var cfg Config
+			if yerr := yaml.Unmarshal(data, &cfg); yerr != nil {
+				return Config{}, fmt.Errorf("parsing %s: %w", candidate, yerr)
+			}
+			return cfg, nil
+		}
+		if !os.IsNotExist(err) {
+			return Config{}, fmt.Errorf("reading %s: %w", candidate, err)
+		}
+
+		// Stop when we reach a git root so we don't wander into parent repos.
+		if _, serr := os.Stat(filepath.Join(dir, ".git")); serr == nil {
+			break
+		}
+
+		parent := filepath.Dir(dir)
+		if parent == dir {
+			break // filesystem root
+		}
+		dir = parent
+	}
+	return Config{}, nil
+}

internal/config/config_test.go

@@ -0,0 +1,112 @@
+package config
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestLoad_NotFound(t *testing.T) {
+	tmp := t.TempDir()
+	cfg, err := Load(tmp)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(cfg.Ignore) != 0 || cfg.Token != "" || cfg.URL != "" {
+		t.Errorf("expected empty config, got %+v", cfg)
+	}
+}
+
+func TestLoad_Found(t *testing.T) {
+	tmp := t.TempDir()
+	content := `
+ignore:
+  - GL007
+  - GL032
+severity:
+  GL004: warning
+stages:
+  - quality
+token: glpat-test
+url: https://gitlab.example.com
+cache_dir: /tmp/glint-cache
+`
+	if err := os.WriteFile(filepath.Join(tmp, Filename), []byte(content), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	cfg, err := Load(tmp)
+	if err != nil {
+		t.Fatalf("Load: %v", err)
+	}
+	if len(cfg.Ignore) != 2 || cfg.Ignore[0] != "GL007" {
+		t.Errorf("ignore = %v", cfg.Ignore)
+	}
+	if cfg.Severity["GL004"] != "warning" {
+		t.Errorf("severity = %v", cfg.Severity)
+	}
+	if len(cfg.Stages) != 1 || cfg.Stages[0] != "quality" {
+		t.Errorf("stages = %v", cfg.Stages)
+	}
+	if cfg.Token != "glpat-test" {
+		t.Errorf("token = %q", cfg.Token)
+	}
+	if cfg.URL != "https://gitlab.example.com" {
+		t.Errorf("url = %q", cfg.URL)
+	}
+	if cfg.CacheDir != "/tmp/glint-cache" {
+		t.Errorf("cache_dir = %q", cfg.CacheDir)
+	}
+}
+
+func TestLoad_WalksUp(t *testing.T) {
+	tmp := t.TempDir()
+	sub := filepath.Join(tmp, "subdir", "pipeline")
+	if err := os.MkdirAll(sub, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	// Config at the top-level (no .git, so walk continues to tmp).
+	if err := os.WriteFile(filepath.Join(tmp, Filename), []byte("token: walked-up\n"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	cfg, err := Load(sub)
+	if err != nil {
+		t.Fatalf("Load: %v", err)
+	}
+	if cfg.Token != "walked-up" {
+		t.Errorf("token = %q, want walked-up", cfg.Token)
+	}
+}
+
+func TestLoad_StopsAtGitRoot(t *testing.T) {
+	tmp := t.TempDir()
+	sub := filepath.Join(tmp, "repo", "src")
+	if err := os.MkdirAll(sub, 0o755); err != nil {
+		t.Fatal(err)
+	}
+	// .git marks the repo root — walk must stop here.
+	if err := os.Mkdir(filepath.Join(tmp, "repo", ".git"), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	// Config placed ABOVE the .git root should not be found.
+	if err := os.WriteFile(filepath.Join(tmp, Filename), []byte("token: should-not-load\n"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	cfg, err := Load(sub)
+	if err != nil {
+		t.Fatalf("Load: %v", err)
+	}
+	if cfg.Token != "" {
+		t.Errorf("token = %q, should not have crossed .git boundary", cfg.Token)
+	}
+}
+
+func TestLoad_InvalidYAML(t *testing.T) {
+	tmp := t.TempDir()
+	if err := os.WriteFile(filepath.Join(tmp, Filename), []byte("ignore: [unclosed\n"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	_, err := Load(tmp)
+	if err == nil {
+		t.Error("expected error for invalid YAML")
+	}
+}

internal/fetcher/cache.go

@@ -0,0 +1,41 @@
+package fetcher
+
+import (
+	"crypto/sha256"
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+// cacheRead returns the cached bytes for the given cache key, or (nil, false)
+// on a miss (key not present, dir empty, or any read error).
+func cacheRead(dir, key string) ([]byte, bool) {
+	if dir == "" {
+		return nil, false
+	}
+	data, err := os.ReadFile(cachePath(dir, key))
+	if err != nil {
+		return nil, false
+	}
+	return data, true
+}
+
+// cacheWrite stores bytes in the cache for the given key. Write errors are
+// silently ignored so cache failures never block the normal fetch path.
+func cacheWrite(dir, key string, data []byte) {
+	if dir == "" {
+		return
+	}
+	if err := os.MkdirAll(dir, 0o755); err != nil {
+		return
+	}
+	_ = os.WriteFile(cachePath(dir, key), data, 0o644)
+}
+
+// cachePath returns the filesystem path for a cache entry.
+// The filename is the SHA-256 hex digest of the key so arbitrary keys (URLs,
+// "project:file@ref" strings) map to safe, stable filenames.
+func cachePath(dir, key string) string {
+	h := sha256.Sum256([]byte(key))
+	return filepath.Join(dir, fmt.Sprintf("%x.yml", h))
+}

internal/fetcher/gitlab.go

@@ -25,6 +25,8 @@ type GitLabConfig struct {
 	BaseURL  string
 	Token    string
 	Source   TokenSource
+	CacheDir string // local cache directory; empty = caching disabled
+	Offline  bool   // when true, return an error instead of making network calls
 }
 
 // AutoConfig builds a GitLabConfig from environment variables.
@@ -54,8 +56,11 @@ func AutoConfig() GitLabConfig {
 	return cfg
 }
 
-// WithOverrides returns a copy of cfg with non-empty overrides applied.
-func (cfg GitLabConfig) WithOverrides(baseURL, token string) GitLabConfig {
+// WithOverrides returns a copy of cfg with the provided overrides applied.
+// Non-empty strings overwrite the corresponding field; booleans are always
+// applied (so offline: false explicitly clears offline mode).
+// cacheDir: empty string disables caching.
+func (cfg GitLabConfig) WithOverrides(baseURL, token, cacheDir string, offline bool) GitLabConfig {
 	if baseURL != "" {
 		cfg.BaseURL = strings.TrimRight(baseURL, "/")
 	}
@@ -63,6 +68,8 @@ func (cfg GitLabConfig) WithOverrides(baseURL, token string) GitLabConfig {
 		cfg.Token = token
 		cfg.Source = TokenPrivate
 	}
+	cfg.CacheDir = cacheDir
+	cfg.Offline = offline
 	return cfg
 }
 
@@ -84,16 +91,24 @@ func (cfg GitLabConfig) HasToken() bool { return cfg.Token != "" }
 //   - filePath — repository file path, e.g. "/templates/ci.yml"
 //   - ref      — branch, tag, or commit SHA; empty string defaults to HEAD
 func (cfg GitLabConfig) FetchFile(project, filePath, ref string) ([]byte, error) {
+	if ref == "" {
+		ref = "HEAD"
+	}
+
+	cKey := cfg.BaseURL + "|" + project + "|" + filePath + "|" + ref
+	if data, ok := cacheRead(cfg.CacheDir, cKey); ok {
+		return data, nil
+	}
+	if cfg.Offline {
+		return nil, fmt.Errorf("offline mode: %s:%s@%s is not in the local cache (run without --offline first to populate the cache)", project, filePath, ref)
+	}
+
 	encodedProject := url.PathEscape(project)
 	encodedFile := url.PathEscape(strings.TrimPrefix(filePath, "/"))
 
 	apiURL := fmt.Sprintf("%s/api/v4/projects/%s/repository/files/%s/raw",
 		cfg.BaseURL, encodedProject, encodedFile)
 
-	if ref == "" {
-		ref = "HEAD"
-	}
-
 	req, err := http.NewRequest(http.MethodGet, apiURL, nil)
 	if err != nil {
 		return nil, fmt.Errorf("building request: %w", err)
@@ -139,12 +154,21 @@ func (cfg GitLabConfig) FetchFile(project, filePath, ref string) ([]byte, error)
 		}
 	}
 
+	cacheWrite(cfg.CacheDir, cKey, body)
 	return body, nil
 }
 
 // FetchURL downloads the content at a plain HTTPS URL without authentication.
 // Used for include: remote: entries which are public by definition.
-func FetchURL(rawURL string) ([]byte, error) {
+// Responses are read from and written to the local cache when CacheDir is set.
+func (cfg GitLabConfig) FetchURL(rawURL string) ([]byte, error) {
+	if data, ok := cacheRead(cfg.CacheDir, rawURL); ok {
+		return data, nil
+	}
+	if cfg.Offline {
+		return nil, fmt.Errorf("offline mode: %s is not in the local cache (run without --offline first to populate the cache)", rawURL)
+	}
+
 	resp, err := http.Get(rawURL) //nolint:noctx
 	if err != nil {
 		return nil, fmt.Errorf("GET %s: %w", rawURL, err)
@@ -157,6 +181,7 @@ func FetchURL(rawURL string) ([]byte, error) {
 	if resp.StatusCode != http.StatusOK {
 		return nil, fmt.Errorf("GET %s: status %d", rawURL, resp.StatusCode)
 	}
+	cacheWrite(cfg.CacheDir, rawURL, body)
 	return body, nil
 }
 

internal/graph/includes.go

@@ -55,9 +55,7 @@ func (b *treeBuilder) nextID() string {
 
 func (b *treeBuilder) buildChildren(parent *treeNode, rawIncludes []any) {
 	for _, entry := range rawIncludes {
-		for _, child := range b.parseEntry(entry) {
-			parent.children = append(parent.children, child)
-		}
+		parent.children = append(parent.children, b.parseEntry(entry)...)
 	}
 }
 
@@ -179,7 +177,7 @@ func (b *treeBuilder) recurseRemote(node *treeNode, rawURL string) {
 	}
 	b.visited[key] = true
 
-	data, err := fetcher.FetchURL(rawURL)
+	data, err := b.cfg.FetchURL(rawURL)
 	if err != nil {
 		return
 	}

internal/linter/dead_rules_test.go

@@ -0,0 +1,90 @@
+package linter
+
+import (
+	"testing"
+
+	"git.k3nny.fr/glint/internal/model"
+)
+
+func TestCheckDeadRules(t *testing.T) {
+	cases := []struct {
+		name     string
+		rules    []model.Rule
+		wantHit  bool // whether GL033 should fire
+	}{
+		{
+			name:    "no rules — not dead",
+			rules:   nil,
+			wantHit: false,
+		},
+		{
+			name:    "single bare when:never — dead",
+			rules:   []model.Rule{{When: "never"}},
+			wantHit: true,
+		},
+		{
+			name: "all rules when:never with if — dead",
+			rules: []model.Rule{
+				{If: `$CI_COMMIT_BRANCH == "main"`, When: "never"},
+				{If: `$CI_COMMIT_BRANCH == "develop"`, When: "never"},
+				{When: "never"},
+			},
+			wantHit: true,
+		},
+		{
+			name: "first rule on_success — not dead",
+			rules: []model.Rule{
+				{If: `$CI_COMMIT_BRANCH == "main"`, When: "on_success"},
+				{When: "never"},
+			},
+			wantHit: false,
+		},
+		{
+			name: "rule with empty when (defaults to on_success) — not dead",
+			rules: []model.Rule{
+				{If: `$CI_COMMIT_BRANCH == "main"`},
+				{When: "never"},
+			},
+			wantHit: false,
+		},
+		{
+			name:    "when:manual — not dead",
+			rules:   []model.Rule{{When: "manual"}},
+			wantHit: false,
+		},
+		{
+			name:    "when:always — not dead",
+			rules:   []model.Rule{{When: "always"}},
+			wantHit: false,
+		},
+		{
+			name:    "when:on_failure — not dead",
+			rules:   []model.Rule{{When: "on_failure"}},
+			wantHit: false,
+		},
+		{
+			name: "mixed never and manual — not dead",
+			rules: []model.Rule{
+				{If: `$CI_COMMIT_BRANCH == "main"`, When: "never"},
+				{When: "manual"},
+			},
+			wantHit: false,
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			job := model.Job{Rules: tc.rules}
+			findings := checkDeadRules("test-job", job)
+			hit := false
+			for _, f := range findings {
+				if f.Rule == RuleDeadRules {
+					hit = true
+				}
+			}
+			if hit != tc.wantHit {
+				t.Errorf("checkDeadRules: got hit=%v, want hit=%v; findings=%v", hit, tc.wantHit, findings)
+			}
+		})
+	}
+}

internal/linter/dependencies.go

@@ -23,6 +23,7 @@ func checkDependencies(p *model.Pipeline) []Finding {
 			if !exists {
 				findings = append(findings, Finding{
 					Severity: Error,
+					Rule:     RuleUnknownDependency,
 					Job:      name,
 					File:     job.File,
 					Line:     job.Line,
@@ -35,6 +36,7 @@ func checkDependencies(p *model.Pipeline) []Finding {
 				if depHasStage && depIdx >= jobStageIdx {
 					findings = append(findings, Finding{
 						Severity: Error,
+						Rule:     RuleDependencyStage,
 						Job:      name,
 						File:     job.File,
 						Line:     job.Line,

internal/linter/explain.go

@@ -0,0 +1,819 @@
+package linter
+
+// RuleEntry holds the human-readable documentation for a single lint rule,
+// shown by 'glint explain <RULE>'.
+type RuleEntry struct {
+	Title       string   // short title (one line)
+	Severity    Severity // Error or Warning
+	Description string   // what triggers the rule and why it matters
+	Example     string   // YAML snippet that triggers the rule
+	Fix         string   // corrected YAML
+}
+
+// RuleCatalog maps stable rule IDs to their documentation entries.
+var RuleCatalog = map[string]RuleEntry{
+	RuleNoStages: {
+		Title:    "no stages defined",
+		Severity: Warning,
+		Description: "The pipeline has no 'stages:' block. GitLab falls back to the " +
+			"built-in default stages (build, test, deploy), which may not match your " +
+			"intended job ordering.",
+		Example: `# No stages: block
+build-job:
+  script: make build
+
+test-job:
+  script: make test`,
+		Fix: `stages:
+  - build
+  - test
+
+build-job:
+  stage: build
+  script: make build
+
+test-job:
+  stage: test
+  script: make test`,
+	},
+
+	RuleWorkflowWhen: {
+		Title:    "workflow.rules.when invalid value",
+		Severity: Error,
+		Description: "'workflow.rules[n].when' only accepts 'always' or 'never'. Any " +
+			"other value (such as 'on_success' or 'manual') is invalid and will cause " +
+			"the pipeline to fail to create.",
+		Example: `workflow:
+  rules:
+    - if: $CI_COMMIT_BRANCH
+      when: on_success   # invalid here`,
+		Fix: `workflow:
+  rules:
+    - if: $CI_COMMIT_BRANCH
+      when: always`,
+	},
+
+	RuleMissingScript: {
+		Title:    "missing required 'script' field",
+		Severity: Error,
+		Description: "Every non-trigger, non-pages job must define 'script:' (or 'run:' " +
+			"for CI Steps). A job with no script will fail immediately when GitLab tries " +
+			"to run it.",
+		Example: `my-job:
+  stage: test
+  image: python:3.12
+  # Missing script:`,
+		Fix: `my-job:
+  stage: test
+  image: python:3.12
+  script: pytest`,
+	},
+
+	RuleUnknownStage: {
+		Title:    "job references undeclared stage",
+		Severity: Error,
+		Description: "The job's 'stage:' value does not match any name in the pipeline's " +
+			"'stages:' list. GitLab will reject the pipeline configuration.",
+		Example: `stages:
+  - build
+  - test
+
+deploy-job:
+  stage: production   # not in stages:
+  script: ./deploy.sh`,
+		Fix: `stages:
+  - build
+  - test
+  - production
+
+deploy-job:
+  stage: production
+  script: ./deploy.sh`,
+	},
+
+	RuleOnlyRulesConflict: {
+		Title:    "'only:' and 'rules:' used together",
+		Severity: Error,
+		Description: "'only:' and 'rules:' are mutually exclusive. Using both on the " +
+			"same job is a configuration error that prevents the pipeline from being " +
+			"created.",
+		Example: `my-job:
+  only:
+    - main
+  rules:
+    - if: $CI_COMMIT_BRANCH
+  script: echo conflict`,
+		Fix: `# Remove only: and use rules: exclusively
+my-job:
+  rules:
+    - if: $CI_COMMIT_BRANCH == "main"
+  script: echo ok`,
+	},
+
+	RuleExceptRulesConflict: {
+		Title:    "'except:' and 'rules:' used together",
+		Severity: Error,
+		Description: "'except:' and 'rules:' are mutually exclusive. Using both on the " +
+			"same job is a configuration error that prevents the pipeline from being " +
+			"created.",
+		Example: `my-job:
+  except:
+    - tags
+  rules:
+    - if: $CI_COMMIT_BRANCH
+  script: echo conflict`,
+		Fix: `my-job:
+  rules:
+    - if: $CI_COMMIT_TAG
+      when: never
+    - if: $CI_COMMIT_BRANCH
+  script: echo ok`,
+	},
+
+	RuleDeprecatedOnly: {
+		Title:    "'only:' / 'except:' deprecated",
+		Severity: Warning,
+		Description: "'only:' and 'except:' are deprecated in favour of 'rules:'. " +
+			"GitLab may remove support for these keywords in a future major version. " +
+			"'rules:' is more expressive and supports variable references, merge-request " +
+			"conditions, and fine-grained 'when:' control.",
+		Example: `my-job:
+  only:
+    - main
+  script: ./deploy.sh`,
+		Fix: `my-job:
+  rules:
+    - if: $CI_COMMIT_BRANCH == "main"
+  script: ./deploy.sh`,
+	},
+
+	RuleInvalidWhen: {
+		Title:    "'when:' has invalid value",
+		Severity: Error,
+		Description: "Job-level 'when:' accepts: on_success, on_failure, always, " +
+			"manual, delayed, never. Any other value is rejected by GitLab.",
+		Example: `my-job:
+  when: sometimes   # invalid
+  script: echo hi`,
+		Fix: `my-job:
+  when: on_success
+  script: echo hi`,
+	},
+
+	RuleDelayedNoStartIn: {
+		Title:    "'when: delayed' without 'start_in:'",
+		Severity: Error,
+		Description: "'when: delayed' requires a 'start_in:' duration (e.g. " +
+			"'30 minutes', '1 hour'). Without it GitLab rejects the job configuration.",
+		Example: `my-job:
+  when: delayed
+  script: echo hi`,
+		Fix: `my-job:
+  when: delayed
+  start_in: 30 minutes
+  script: echo hi`,
+	},
+
+	RuleStartInNoDelayed: {
+		Title:    "'start_in:' without 'when: delayed'",
+		Severity: Error,
+		Description: "'start_in:' is only meaningful when 'when: delayed'. Setting it " +
+			"alongside any other 'when:' value is a configuration error.",
+		Example: `my-job:
+  when: on_success
+  start_in: 30 minutes   # only valid with delayed
+  script: echo hi`,
+		Fix: `my-job:
+  when: delayed
+  start_in: 30 minutes
+  script: echo hi`,
+	},
+
+	RuleInvalidParallel: {
+		Title:    "'parallel:' value invalid",
+		Severity: Error,
+		Description: "'parallel:' must be an integer between 2 and 200 (inclusive), " +
+			"or a map with a 'matrix:' key for matrix jobs. Values outside this range " +
+			"or the wrong type are rejected by GitLab.",
+		Example: `my-job:
+  parallel: 1   # must be 2–200
+  script: echo hi`,
+		Fix: `my-job:
+  parallel: 5
+  script: echo hi`,
+	},
+
+	RuleInvalidRetry: {
+		Title:    "'retry:' value invalid",
+		Severity: Error,
+		Description: "'retry:' accepts an integer 0–2 or a map with optional 'max:' " +
+			"(0–2) and 'when:' keys. Values outside this range are rejected.",
+		Example: `my-job:
+  retry: 5   # max is 2
+  script: echo hi`,
+		Fix: `my-job:
+  retry: 2
+  script: echo hi`,
+	},
+
+	RuleInvalidRetryWhen: {
+		Title:    "'retry.when:' has invalid failure type",
+		Severity: Error,
+		Description: "'retry.when:' must be a recognised GitLab CI failure type " +
+			"(e.g. script_failure, runner_system_failure) or 'always'. Unknown " +
+			"values are rejected.",
+		Example: `my-job:
+  retry:
+    max: 2
+    when: disk_full   # not a valid failure type
+  script: echo hi`,
+		Fix: `my-job:
+  retry:
+    max: 2
+    when: runner_system_failure
+  script: echo hi`,
+	},
+
+	RuleInvalidAllowFailure: {
+		Title:    "'allow_failure:' invalid value",
+		Severity: Error,
+		Description: "'allow_failure:' must be a boolean (true/false) or a map with " +
+			"an 'exit_codes:' key. Other forms are rejected by GitLab.",
+		Example: `my-job:
+  allow_failure: maybe   # must be true/false or map
+  script: echo hi`,
+		Fix: `my-job:
+  allow_failure: true
+  script: echo hi`,
+	},
+
+	RuleInvalidInterruptible: {
+		Title:    "'interruptible:' is not a boolean",
+		Severity: Error,
+		Description: "'interruptible:' must be a boolean (true or false). Other types " +
+			"are rejected.",
+		Example: `my-job:
+  interruptible: yes   # must be a YAML boolean true/false
+  script: echo hi`,
+		Fix: `my-job:
+  interruptible: true
+  script: echo hi`,
+	},
+
+	RuleTriggerWithScript: {
+		Title:    "trigger job also defines 'script:'",
+		Severity: Error,
+		Description: "Jobs with a 'trigger:' key (downstream pipeline triggers) cannot " +
+			"use 'script:'. These are mutually exclusive — a trigger job has no runner " +
+			"environment to execute scripts in.",
+		Example: `trigger-job:
+  trigger:
+    project: mygroup/myproject
+  script: echo this will fail`,
+		Fix: `trigger-job:
+  trigger:
+    project: mygroup/myproject`,
+	},
+
+	RuleInvalidTrigger: {
+		Title:    "trigger: map missing 'project:' or 'include:'",
+		Severity: Error,
+		Description: "When 'trigger:' is a map it must specify either 'project:' " +
+			"(downstream project trigger) or 'include:' (dynamic child pipeline). " +
+			"Without one of these keys GitLab cannot determine what to trigger.",
+		Example: `trigger-job:
+  trigger:
+    strategy: depend   # missing project: or include:`,
+		Fix: `trigger-job:
+  trigger:
+    project: mygroup/downstream
+    strategy: depend`,
+	},
+
+	RuleInvalidCoverage: {
+		Title:    "'coverage:' is not a regex pattern",
+		Severity: Error,
+		Description: "'coverage:' must be a regex pattern wrapped in forward slashes " +
+			"(e.g. '/Coverage: \\d+\\.?\\d*%/'). GitLab uses this pattern to extract " +
+			"the coverage percentage from job output.",
+		Example: `my-job:
+  coverage: "\\d+%"   # missing surrounding /…/
+  script: pytest --cov`,
+		Fix: `my-job:
+  coverage: '/Coverage: \d+\.?\d*%/'
+  script: pytest --cov`,
+	},
+
+	RuleInvalidRelease: {
+		Title:    "'release:' missing required 'tag_name:'",
+		Severity: Error,
+		Description: "'release:' must be a map and must include a 'tag_name:' key. " +
+			"Without it GitLab cannot create the release.",
+		Example: `release-job:
+  script: echo releasing
+  release:
+    name: My Release   # missing tag_name:`,
+		Fix: `release-job:
+  script: echo releasing
+  release:
+    tag_name: $CI_COMMIT_TAG
+    name: My Release`,
+	},
+
+	RuleInvalidEnvironment: {
+		Title:    "'environment:' invalid url or action",
+		Severity: Error,
+		Description: "'environment.url' requires 'environment.name' to be set. " +
+			"'environment.action' must be one of: start, stop, prepare, verify, access.",
+		Example: `my-job:
+  script: ./deploy.sh
+  environment:
+    url: https://prod.example.com   # name: is required`,
+		Fix: `my-job:
+  script: ./deploy.sh
+  environment:
+    name: production
+    url: https://prod.example.com`,
+	},
+
+	RuleInvalidArtifacts: {
+		Title:    "'artifacts:' invalid configuration",
+		Severity: Error,
+		Description: "'artifacts.when' must be on_success, on_failure, or always. " +
+			"'artifacts.expose_as' requires 'artifacts.paths' to be set.",
+		Example: `my-job:
+  script: make
+  artifacts:
+    when: sometimes   # invalid value`,
+		Fix: `my-job:
+  script: make
+  artifacts:
+    when: on_failure
+    paths:
+      - build/logs/`,
+	},
+
+	RulePagesPublic: {
+		Title:    "pages job missing 'public' in artifacts.paths",
+		Severity: Warning,
+		Description: "The 'pages' job must include 'public' (or a path starting with " +
+			"'public/') in 'artifacts.paths' for GitLab Pages to deploy the site.",
+		Example: `pages:
+  script: hugo
+  artifacts:
+    paths:
+      - dist/   # should include public/`,
+		Fix: `pages:
+  script: hugo --destination public
+  artifacts:
+    paths:
+      - public/`,
+	},
+
+	RuleInvalidCache: {
+		Title:    "'cache:' invalid when or policy",
+		Severity: Error,
+		Description: "'cache.when' must be on_success, on_failure, or always. " +
+			"'cache.policy' must be pull, push, or pull-push.",
+		Example: `my-job:
+  script: npm ci
+  cache:
+    paths: [node_modules/]
+    policy: read-only   # invalid; use pull`,
+		Fix: `my-job:
+  script: npm ci
+  cache:
+    paths: [node_modules/]
+    policy: pull`,
+	},
+
+	RuleInvalidRulesWhen: {
+		Title:    "'rules[n].when:' has invalid value",
+		Severity: Error,
+		Description: "Inside a 'rules:' block, 'when:' must be one of: on_success, " +
+			"on_failure, always, manual, delayed, never. Other values are rejected.",
+		Example: `my-job:
+  rules:
+    - if: $CI_COMMIT_BRANCH
+      when: conditional   # not valid here
+  script: echo hi`,
+		Fix: `my-job:
+  rules:
+    - if: $CI_COMMIT_BRANCH
+      when: on_success
+  script: echo hi`,
+	},
+
+	RuleInvalidImage: {
+		Title:    "'image:' map form missing 'name:'",
+		Severity: Error,
+		Description: "When 'image:' is a map, it must include a 'name:' key specifying " +
+			"the Docker image. Without it GitLab cannot resolve which image to pull.",
+		Example: `my-job:
+  image:
+    entrypoint: ["/bin/sh"]   # missing name:
+  script: echo hi`,
+		Fix: `my-job:
+  image:
+    name: alpine:3.19
+    entrypoint: ["/bin/sh"]
+  script: echo hi`,
+	},
+
+	RuleInvalidInherit: {
+		Title:    "'inherit.default' or 'inherit.variables' invalid type",
+		Severity: Error,
+		Description: "'inherit.default' and 'inherit.variables' must each be a boolean " +
+			"(true/false) or a list of field/variable names. Other types are rejected.",
+		Example: `my-job:
+  inherit:
+    default: "no"   # must be true/false or a list
+  script: echo hi`,
+		Fix: `my-job:
+  inherit:
+    default: false
+  script: echo hi`,
+	},
+
+	RuleNeedsUnknown: {
+		Title:    "'needs:' references unknown job",
+		Severity: Error,
+		Description: "A job in the 'needs:' list does not exist in the pipeline. " +
+			"GitLab will refuse to create the pipeline.",
+		Example: `build:
+  stage: build
+  script: make
+
+test:
+  stage: test
+  needs: [build, lint]   # lint does not exist
+  script: make test`,
+		Fix: `lint:
+  stage: build
+  script: make lint
+
+build:
+  stage: build
+  script: make
+
+test:
+  stage: test
+  needs: [build, lint]
+  script: make test`,
+	},
+
+	RuleNeedsStageOrder: {
+		Title:    "'needs:' job is in a later stage",
+		Severity: Error,
+		Description: "A job listed in 'needs:' is in a later stage than the current " +
+			"job. GitLab does not allow needs: to reference future stages.",
+		Example: `stages: [build, test, deploy]
+
+test:
+  stage: test
+  needs: [deploy-job]   # deploy-job is in a later stage
+  script: make test
+
+deploy-job:
+  stage: deploy
+  script: ./deploy.sh`,
+		Fix: `stages: [build, test, deploy]
+
+test:
+  stage: test
+  needs: [build-job]
+  script: make test
+
+build-job:
+  stage: build
+  script: make`,
+	},
+
+	RuleNeedsCycle: {
+		Title:    "circular dependency in 'needs:' graph",
+		Severity: Error,
+		Description: "Two or more jobs in the 'needs:' graph form a cycle — A needs B " +
+			"and B needs A (directly or transitively). GitLab will reject the pipeline.",
+		Example: `job-a:
+  stage: test
+  needs: [job-b]
+  script: echo a
+
+job-b:
+  stage: test
+  needs: [job-a]
+  script: echo b`,
+		Fix: `job-a:
+  stage: test
+  script: echo a
+
+job-b:
+  stage: test
+  needs: [job-a]
+  script: echo b`,
+	},
+
+	RuleUnknownDependency: {
+		Title:    "'dependencies:' references unknown job",
+		Severity: Error,
+		Description: "A job listed in 'dependencies:' does not exist in the pipeline. " +
+			"GitLab will refuse to create the pipeline.",
+		Example: `test:
+  stage: test
+  dependencies: [build, missing-job]
+  script: make test`,
+		Fix: `build:
+  stage: build
+  script: make
+  artifacts:
+    paths: [dist/]
+
+test:
+  stage: test
+  dependencies: [build]
+  script: make test`,
+	},
+
+	RuleDependencyStage: {
+		Title:    "'dependencies:' job in same or later stage",
+		Severity: Error,
+		Description: "'dependencies:' can only reference jobs in earlier stages. " +
+			"Referencing a job in the same or a later stage is not allowed because " +
+			"artifacts would not yet be available.",
+		Example: `stages: [test, deploy]
+
+test:
+  stage: test
+  dependencies: [deploy-job]   # deploy is a later stage
+  script: make test
+
+deploy-job:
+  stage: deploy
+  script: ./deploy.sh`,
+		Fix: `stages: [build, test, deploy]
+
+build:
+  stage: build
+  script: make
+  artifacts:
+    paths: [dist/]
+
+test:
+  stage: test
+  dependencies: [build]
+  script: make test`,
+	},
+
+	RuleUndeclaredVariable: {
+		Title:    "'rules:if:' references undeclared variable",
+		Severity: Warning,
+		Description: "A 'rules:if:' expression references a variable that is not " +
+			"declared in any 'variables:' block in the pipeline YAML. This may be a " +
+			"typo, or the variable may be set in GitLab project settings (invisible to " +
+			"glint). Predefined CI_* and GITLAB_* variables are always exempt.",
+		Example: `variables:
+  APP_ENV: staging
+
+my-job:
+  rules:
+    - if: $DEPLOY_ENV == "prod"   # DEPLOY_ENV not declared
+  script: ./deploy.sh`,
+		Fix: `variables:
+  APP_ENV: staging
+  DEPLOY_ENV: staging   # declare it, or set it in GitLab project settings
+
+my-job:
+  rules:
+    - if: $DEPLOY_ENV == "prod"
+  script: ./deploy.sh`,
+	},
+
+	RuleDeadRules: {
+		Title:    "rules: block has all 'when: never' — job permanently excluded",
+		Severity: Warning,
+		Description: "Every rule in the job's 'rules:' block has an explicit " +
+			"'when: never'. No matter which conditions match, the job will never " +
+			"be included in any pipeline run.",
+		Example: `my-job:
+  rules:
+    - if: $CI_COMMIT_BRANCH == "main"
+      when: never
+    - when: never
+  script: echo unreachable`,
+		Fix: `# Option 1: remove the job entirely
+# Option 2: give at least one rule a non-never when:
+my-job:
+  rules:
+    - if: $CI_COMMIT_BRANCH == "main"
+      when: on_success
+    - when: never
+  script: echo deploy`,
+	},
+
+	RuleInvalidService: {
+		Title:    "'services:' map form missing 'name:' or invalid 'alias:'",
+		Severity: Error,
+		Description: "When a service entry is a map it must include a 'name:' key. " +
+			"'alias:' (if set) must be a valid DNS label: alphanumeric characters, " +
+			"hyphens, and dots only; must start and end with alphanumeric.",
+		Example: `my-job:
+  script: pytest
+  services:
+    - alias: my_db   # underscore is not valid in a DNS label`,
+		Fix: `my-job:
+  script: pytest
+  services:
+    - name: postgres:15
+      alias: my-db`,
+	},
+
+	RuleAbsoluteGlobPath: {
+		Title:    "'rules:changes' or 'rules:exists' uses absolute path",
+		Severity: Warning,
+		Description: "Paths in 'rules:changes' and 'rules:exists' are always relative " +
+			"to the repository root. An absolute path starting with '/' will never " +
+			"match any file and will silently disable the rule.",
+		Example: `my-job:
+  rules:
+    - changes:
+        - /src/**/*.go   # absolute — will never match
+  script: make`,
+		Fix: `my-job:
+  rules:
+    - changes:
+        - src/**/*.go
+  script: make`,
+	},
+
+	RuleInvalidTimeout: {
+		Title:    "'timeout:' is not a valid duration string",
+		Severity: Error,
+		Description: "'timeout:' must be a GitLab CI duration string composed of " +
+			"recognised time units: weeks (w), days (d), hours (h), minutes (m/min), " +
+			"seconds (s). Examples: '1h 30m', '90 minutes', '2 hours'.",
+		Example: `my-job:
+  timeout: "1:30:00"   # colon-separated format not supported
+  script: long-running-task.sh`,
+		Fix: `my-job:
+  timeout: 1h 30m
+  script: long-running-task.sh`,
+	},
+
+	RuleInvalidIDToken: {
+		Title:    "'id_tokens:' entry missing required 'aud:' key",
+		Severity: Error,
+		Description: "Each entry under 'id_tokens:' must be a map with an 'aud:' " +
+			"(audience) key. Without 'aud:' GitLab cannot generate the ID token " +
+			"and the job will fail.",
+		Example: `my-job:
+  id_tokens:
+    MY_TOKEN:
+      # missing aud:
+  script: vault-login.sh`,
+		Fix: `my-job:
+  id_tokens:
+    MY_TOKEN:
+      aud: https://vault.example.com
+  script: vault-login.sh`,
+	},
+
+	RuleInvalidSecret: {
+		Title:    "'secrets:' entry missing a provider key",
+		Severity: Error,
+		Description: "Each entry under 'secrets:' must specify a provider: one of " +
+			"'vault:', 'gcp_secret_manager:', or 'azure_key_vault:'. Without a " +
+			"provider GitLab cannot retrieve the secret.",
+		Example: `my-job:
+  secrets:
+    DB_PASSWORD:
+      path: secret/db/password   # no provider key
+  script: run.sh`,
+		Fix: `my-job:
+  secrets:
+    DB_PASSWORD:
+      vault:
+        engine:
+          name: kv-v2
+          path: secret
+        path: db/password
+        field: password
+  script: run.sh`,
+	},
+
+	RulePagesPublish: {
+		Title:    "'pages:' keyword publish directory missing from 'artifacts.paths'",
+		Severity: Warning,
+		Description: "A job using the 'pages:' keyword must include its publish " +
+			"directory in 'artifacts.paths'. Without this, GitLab Pages will not " +
+			"deploy the site.",
+		Example: `my-pages-job:
+  script: hugo
+  pages:
+    publish: public
+  artifacts:
+    paths:
+      - dist/   # missing public/`,
+		Fix: `my-pages-job:
+  script: hugo
+  pages:
+    publish: public
+  artifacts:
+    paths:
+      - public/`,
+	},
+
+	RuleDuplicateStage: {
+		Title:    "duplicate stage name in 'stages:'",
+		Severity: Warning,
+		Description: "A stage name appears more than once in the 'stages:' list. " +
+			"GitLab silently merges duplicate stage entries, which can make the " +
+			"pipeline order confusing.",
+		Example: `stages:
+  - build
+  - test
+  - test   # duplicate`,
+		Fix: `stages:
+  - build
+  - test`,
+	},
+
+	RuleInvalidCacheKeyFiles: {
+		Title:    "'cache.key.files' contains a glob pattern",
+		Severity: Warning,
+		Description: "'cache.key.files' must be a list of exact file paths. Glob " +
+			"patterns (*, ?, [...]) are not expanded — the literal glob string is " +
+			"used as the cache key, which probably doesn't match your intent.",
+		Example: `my-job:
+  script: npm ci
+  cache:
+    key:
+      files:
+        - package*.json   # glob — use exact path`,
+		Fix: `my-job:
+  script: npm ci
+  cache:
+    key:
+      files:
+        - package.json
+        - package-lock.json`,
+	},
+
+	RuleStaticDeadRules: {
+		Title:    "rules:if: block statically never activates",
+		Severity: Warning,
+		Description: "Every 'rules:if:' condition in this job evaluates to false " +
+			"using the variable values declared in the pipeline YAML. The job will " +
+			"never be included in any pipeline run. This check only fires when ALL " +
+			"referenced variables are declared in the YAML (predefined CI_* variables " +
+			"are not evaluated to avoid false positives).",
+		Example: `variables:
+  ENABLE_DEPLOY: "false"
+
+deploy:
+  rules:
+    - if: '$ENABLE_DEPLOY == "true"'   # always false: ENABLE_DEPLOY is "false"
+  script: ./deploy.sh`,
+		Fix: `variables:
+  ENABLE_DEPLOY: "true"   # fix the variable value
+
+deploy:
+  rules:
+    - if: '$ENABLE_DEPLOY == "true"'
+  script: ./deploy.sh
+
+# Or add an unconditional fallback:
+deploy:
+  rules:
+    - if: '$ENABLE_DEPLOY == "true"'
+    - when: manual   # allow manual trigger as a fallback
+  script: ./deploy.sh`,
+	},
+
+	RuleInheritNoDefault: {
+		Title:    "'inherit: default:' declared but no 'default:' block",
+		Severity: Warning,
+		Description: "A job declares 'inherit: default:' but the pipeline has no " +
+			"'default:' block, so the declaration has no effect. This can also fire " +
+			"when 'inherit: default: [list]' names fields that are not set in the " +
+			"'default:' block.",
+		Example: `# No default: block exists
+
+my-job:
+  inherit:
+    default: false   # no-op: nothing to opt out of
+  script: echo hi`,
+		Fix: `# Either add a default: block...
+default:
+  before_script:
+    - source venv/bin/activate
+
+my-job:
+  inherit:
+    default: false
+  script: echo hi
+
+# ...or remove the pointless inherit: declaration
+my-job:
+  script: echo hi`,
+	},
+}

internal/linter/if_reachability.go

@@ -0,0 +1,104 @@
+package linter
+
+import (
+	"git.k3nny.fr/glint/internal/cicontext"
+	"git.k3nny.fr/glint/internal/model"
+)
+
+// checkRulesIfReachability (GL042): warn when every rule in a job's rules: block
+// can be statically proven to never activate given the values of variables
+// declared in the pipeline YAML. Only fires when ALL variables referenced by the
+// rules:if: expressions are declared in the pipeline or job variables: blocks —
+// predefined CI_* / GITLAB_* variables or variables not declared in YAML are
+// treated as unknown (could have any runtime value) so the check is skipped
+// conservatively to avoid false positives.
+func checkRulesIfReachability(p *model.Pipeline) []Finding {
+	if len(p.Jobs) == 0 {
+		return nil
+	}
+
+	// Collect scalar string values from pipeline-level variables.
+	pipelineVars := make(map[string]string, len(p.Variables))
+	for k, v := range p.Variables {
+		if s, ok := cicontext.ScalarString(v); ok {
+			pipelineVars[k] = s
+		}
+	}
+
+	var findings []Finding
+	for name, job := range p.Jobs {
+		if len(job.Rules) == 0 {
+			continue
+		}
+
+		// Merge pipeline vars with job-level variable overrides.
+		jobVars := make(map[string]string, len(pipelineVars)+len(job.Variables))
+		for k, v := range pipelineVars {
+			jobVars[k] = v
+		}
+		for k, v := range job.Variables {
+			if s, ok := cicontext.ScalarString(v); ok {
+				jobVars[k] = s
+			}
+		}
+
+		if f := evalRulesReachability(name, job, jobVars); f != nil {
+			findings = append(findings, *f)
+		}
+	}
+	return findings
+}
+
+// evalRulesReachability returns a GL042 finding when the job's rules: block
+// can never activate given the provided variable map, or nil if the job
+// might activate (or the check cannot be applied conservatively).
+func evalRulesReachability(name string, job model.Job, jobVars map[string]string) *Finding {
+	lookup := func(k string) string { return jobVars[k] }
+
+	for _, rule := range job.Rules {
+		// Explicit when: never — this rule is provably dead; continue.
+		if rule.When == "never" {
+			continue
+		}
+
+		// No if: condition → this rule always matches → job CAN activate.
+		if rule.If == "" {
+			return nil
+		}
+
+		// Check whether all variables referenced in the if: expression are
+		// declared in the pipeline YAML. If any are not declared (predefined
+		// CI vars, project settings, etc.), we cannot evaluate the expression
+		// and must conservatively assume the job might activate.
+		refs := extractIfVars(rule.If)
+		allDeclared := true
+		for _, ref := range refs {
+			if _, ok := jobVars[ref]; !ok {
+				// Variable not in YAML (predefined or unknown) → cannot evaluate.
+				allDeclared = false
+				break
+			}
+		}
+		if !allDeclared {
+			return nil // conservative: job might activate
+		}
+
+		// All referenced variables are declared; evaluate the expression.
+		// Use strict mode (unparse → false) to avoid matching unparseable expressions.
+		if cicontext.EvalIfStrict(rule.If, lookup) {
+			// This rule's condition evaluates to true → job CAN activate.
+			return nil
+		}
+		// Expression evaluated to false → this rule cannot activate; continue.
+	}
+
+	// No rule could activate the job.
+	return &Finding{
+		Severity: Warning,
+		Rule:     RuleStaticDeadRules,
+		Job:      name,
+		File:     job.File,
+		Line:     job.Line,
+		Message:  "rules: block can never activate: all if: conditions evaluate to false given the declared pipeline variables",
+	}
+}

internal/linter/if_reachability_test.go

@@ -0,0 +1,152 @@
+package linter
+
+import (
+	"testing"
+
+	"git.k3nny.fr/glint/internal/model"
+)
+
+func TestCheckRulesIfReachability(t *testing.T) {
+	makeJob := func(vars map[string]any, rules []model.Rule) model.Job {
+		return model.Job{Variables: vars, Rules: rules}
+	}
+
+	cases := []struct {
+		name        string
+		pipelineVars map[string]any
+		jobs        map[string]model.Job
+		wantHit     []string // job names that should produce GL042
+		wantMiss    []string // job names that should NOT produce GL042
+	}{
+		{
+			name:         "declared var always false — GL042 fires",
+			pipelineVars: map[string]any{"DEPLOY": "false"},
+			jobs: map[string]model.Job{
+				"deploy": makeJob(nil, []model.Rule{
+					{If: `$DEPLOY == "true"`, When: "on_success"},
+				}),
+			},
+			wantHit:  []string{"deploy"},
+			wantMiss: nil,
+		},
+		{
+			name:         "declared var matches — no finding",
+			pipelineVars: map[string]any{"DEPLOY": "true"},
+			jobs: map[string]model.Job{
+				"deploy": makeJob(nil, []model.Rule{
+					{If: `$DEPLOY == "true"`, When: "on_success"},
+				}),
+			},
+			wantHit:  nil,
+			wantMiss: []string{"deploy"},
+		},
+		{
+			name:         "predefined CI_ var — skip check conservatively",
+			pipelineVars: nil,
+			jobs: map[string]model.Job{
+				"branch-job": makeJob(nil, []model.Rule{
+					{If: `$CI_COMMIT_BRANCH == "never-exists"`, When: "on_success"},
+				}),
+			},
+			wantHit:  nil,
+			wantMiss: []string{"branch-job"},
+		},
+		{
+			name:         "undeclared var — skip check conservatively",
+			pipelineVars: nil,
+			jobs: map[string]model.Job{
+				"my-job": makeJob(nil, []model.Rule{
+					{If: `$UNKNOWN_VAR == "x"`, When: "on_success"},
+				}),
+			},
+			wantHit:  nil,
+			wantMiss: []string{"my-job"},
+		},
+		{
+			name:         "unconditional rule — job can always activate",
+			pipelineVars: map[string]any{"DEPLOY": "false"},
+			jobs: map[string]model.Job{
+				"my-job": makeJob(nil, []model.Rule{
+					{If: `$DEPLOY == "true"`, When: "never"},
+					{When: "on_success"},
+				}),
+			},
+			wantHit:  nil,
+			wantMiss: []string{"my-job"},
+		},
+		{
+			name:         "all rules when:never — GL042 fires (not GL033 territory overlap)",
+			pipelineVars: map[string]any{"DEPLOY": "false"},
+			jobs: map[string]model.Job{
+				"my-job": makeJob(nil, []model.Rule{
+					{If: `$DEPLOY == "true"`, When: "on_success"},
+					{When: "never"},
+				}),
+			},
+			// Rule 1 evaluates to false; Rule 2 is explicit never → all dead.
+			wantHit:  []string{"my-job"},
+			wantMiss: nil,
+		},
+		{
+			name:         "job-level var overrides pipeline var",
+			pipelineVars: map[string]any{"FLAG": "false"},
+			jobs: map[string]model.Job{
+				"my-job": makeJob(map[string]any{"FLAG": "true"}, []model.Rule{
+					{If: `$FLAG == "true"`, When: "on_success"},
+				}),
+			},
+			// Job-level FLAG="true" makes the if: evaluate to true → no finding.
+			wantHit:  nil,
+			wantMiss: []string{"my-job"},
+		},
+		{
+			name:         "no rules — nothing to check",
+			pipelineVars: map[string]any{"DEPLOY": "false"},
+			jobs: map[string]model.Job{
+				"my-job": makeJob(nil, nil),
+			},
+			wantHit:  nil,
+			wantMiss: []string{"my-job"},
+		},
+		{
+			name:         "boolean variable evaluates correctly",
+			pipelineVars: map[string]any{"FLAG": false}, // bool false
+			jobs: map[string]model.Job{
+				"my-job": makeJob(nil, []model.Rule{
+					{If: `$FLAG == "true"`, When: "on_success"},
+				}),
+			},
+			// ScalarString(false) → "false"; "false" == "true" → false → GL042 fires.
+			wantHit:  []string{"my-job"},
+			wantMiss: nil,
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			p := &model.Pipeline{
+				Variables: tc.pipelineVars,
+				Jobs:      tc.jobs,
+			}
+			findings := checkRulesIfReachability(p)
+
+			hitSet := make(map[string]bool)
+			for _, f := range findings {
+				if f.Rule == RuleStaticDeadRules {
+					hitSet[f.Job] = true
+				}
+			}
+
+			for _, want := range tc.wantHit {
+				if !hitSet[want] {
+					t.Errorf("expected GL042 for job %q but it was not reported; findings: %v", want, findings)
+				}
+			}
+			for _, notWant := range tc.wantMiss {
+				if hitSet[notWant] {
+					t.Errorf("unexpected GL042 for job %q", notWant)
+				}
+			}
+		})
+	}
+}

internal/linter/inherit_completeness.go

@@ -0,0 +1,112 @@
+package linter
+
+import (
+	"fmt"
+	"strings"
+
+	"git.k3nny.fr/glint/internal/model"
+)
+
+// checkInheritCompleteness (GL043): warn when a job's 'inherit: default:'
+// declaration is dead — either because there is no 'default:' block in the
+// pipeline, or because the list form references fields that are not defined
+// in the 'default:' block.
+func checkInheritCompleteness(p *model.Pipeline) []Finding {
+	var findings []Finding
+	for name, job := range p.Jobs {
+		findings = append(findings, checkJobInheritCompleteness(p, name, job)...)
+	}
+	return findings
+}
+
+func checkJobInheritCompleteness(p *model.Pipeline, name string, job model.Job) []Finding {
+	if job.Inherit == nil {
+		return nil
+	}
+	m, ok := job.Inherit.(map[string]any)
+	if !ok {
+		return nil
+	}
+	defaultVal, hasDefault := m["default"]
+	if !hasDefault {
+		return nil
+	}
+
+	// Case 1: no default: block at all — the entire declaration is a no-op.
+	if p.Default == nil {
+		return []Finding{{
+			Severity: Warning,
+			Rule:     RuleInheritNoDefault,
+			Job:      name,
+			File:     job.File,
+			Line:     job.Line,
+			Message:  "'inherit: default:' is declared but the pipeline has no 'default:' block — declaration has no effect",
+		}}
+	}
+
+	// Case 2: list form — check for field names not set in default:.
+	list, ok := defaultVal.([]any)
+	if !ok {
+		// bool form (true/false) with a non-nil default: block is always valid.
+		return nil
+	}
+
+	var dead []string
+	for _, item := range list {
+		field, ok := item.(string)
+		if !ok {
+			continue
+		}
+		if !defaultBlockHasField(p.Default, field) {
+			dead = append(dead, field)
+		}
+	}
+	if len(dead) == 0 {
+		return nil
+	}
+	return []Finding{{
+		Severity: Warning,
+		Rule:     RuleInheritNoDefault,
+		Job:      name,
+		File:     job.File,
+		Line:     job.Line,
+		Message: fmt.Sprintf(
+			"'inherit: default: [%s]': %s not defined in the 'default:' block — %s",
+			strings.Join(dead, ", "),
+			pluralIs(len(dead)),
+			"these entries have no effect",
+		),
+	}}
+}
+
+// defaultBlockHasField reports whether the given field name has a non-zero value
+// in the default: block. Unknown field names return true (conservative).
+func defaultBlockHasField(d *model.DefaultConfig, field string) bool {
+	switch field {
+	case "image":
+		return d.Image != nil
+	case "before_script":
+		return d.BeforeScript != nil
+	case "after_script":
+		return d.AfterScript != nil
+	case "cache":
+		return d.Cache != nil
+	case "artifacts":
+		return d.Artifacts != nil
+	case "retry":
+		return d.Retry != nil
+	case "timeout":
+		return d.Timeout != ""
+	case "tags":
+		return len(d.Tags) > 0
+	}
+	// Unknown field name — conservatively assume it might be defined.
+	return true
+}
+
+func pluralIs(n int) string {
+	if n == 1 {
+		return "this field is"
+	}
+	return "these fields are"
+}

internal/linter/inherit_completeness_test.go

@@ -0,0 +1,94 @@
+package linter
+
+import (
+	"testing"
+
+	"git.k3nny.fr/glint/internal/model"
+)
+
+func TestCheckInheritCompleteness(t *testing.T) {
+	cases := []struct {
+		name    string
+		default_ *model.DefaultConfig
+		inherit any // job.Inherit value
+		wantHit bool
+	}{
+		{
+			name:    "no inherit — no finding",
+			inherit: nil,
+			wantHit: false,
+		},
+		{
+			name:    "inherit: default: false, no default block — GL043",
+			inherit: map[string]any{"default": false},
+			wantHit: true,
+		},
+		{
+			name:    "inherit: default: true, no default block — GL043",
+			inherit: map[string]any{"default": true},
+			wantHit: true,
+		},
+		{
+			name:    "inherit: default: [image], no default block — GL043",
+			inherit: map[string]any{"default": []any{"image"}},
+			wantHit: true,
+		},
+		{
+			name:     "inherit: default: false, default block exists — no finding",
+			default_: &model.DefaultConfig{Image: "node:20"},
+			inherit:  map[string]any{"default": false},
+			wantHit:  false,
+		},
+		{
+			name:     "inherit: default: [image], image in default — no finding",
+			default_: &model.DefaultConfig{Image: "node:20"},
+			inherit:  map[string]any{"default": []any{"image"}},
+			wantHit:  false,
+		},
+		{
+			name:     "inherit: default: [before_script], before_script NOT in default — GL043",
+			default_: &model.DefaultConfig{Image: "node:20"},
+			inherit:  map[string]any{"default": []any{"before_script"}},
+			wantHit:  true,
+		},
+		{
+			name:     "inherit: default: [image, before_script], only image in default — GL043 for before_script",
+			default_: &model.DefaultConfig{Image: "node:20"},
+			inherit:  map[string]any{"default": []any{"image", "before_script"}},
+			wantHit:  true,
+		},
+		{
+			name:     "inherit: variables only — no default check",
+			default_: nil,
+			inherit:  map[string]any{"variables": false},
+			wantHit:  false,
+		},
+		{
+			name:     "inherit: unknown field in list — conservative, no finding",
+			default_: &model.DefaultConfig{Image: "node:20"},
+			inherit:  map[string]any{"default": []any{"nonexistent_field"}},
+			wantHit:  false, // unknown fields return true from defaultBlockHasField
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			job := model.Job{Inherit: tc.inherit}
+			p := &model.Pipeline{
+				Default: tc.default_,
+				Jobs:    map[string]model.Job{"test-job": job},
+			}
+			findings := checkInheritCompleteness(p)
+
+			hit := false
+			for _, f := range findings {
+				if f.Rule == RuleInheritNoDefault {
+					hit = true
+				}
+			}
+			if hit != tc.wantHit {
+				t.Errorf("GL043 hit=%v, want=%v; findings: %v", hit, tc.wantHit, findings)
+			}
+		})
+	}
+}

internal/linter/keywords.go

@@ -8,6 +8,15 @@ import (
 	"git.k3nny.fr/glint/internal/model"
 )
 
+// dnsLabelPattern matches a valid hostname label: starts and ends with
+// alphanumeric, middle may contain hyphens and dots; max 63 chars per label.
+var dnsLabelPattern = regexp.MustCompile(`^[a-zA-Z0-9]([a-zA-Z0-9.-]{0,61}[a-zA-Z0-9])?$`)
+
+// timeoutPattern matches a GitLab CI duration string: one or more pairs of
+// "<number> <unit>" where unit is a recognised time word or abbreviation.
+var timeoutPattern = regexp.MustCompile(
+	`(?i)^\s*(\d+\s*(weeks?|w|days?|d|hours?|h|minutes?|mins?|m|seconds?|secs?|s)\s*)+$`)
+
 var validJobWhen = map[string]bool{
 	"on_success": true,
 	"on_failure": true,
@@ -95,8 +104,16 @@ func checkJobKeywords(name string, job model.Job) []Finding {
 	findings = append(findings, checkArtifacts(name, job)...)
 	findings = append(findings, checkCache(name, job)...)
 	findings = append(findings, checkRules(name, job)...)
+	findings = append(findings, checkDeadRules(name, job)...)
 	findings = append(findings, checkImage(name, job)...)
 	findings = append(findings, checkInherit(name, job)...)
+	findings = append(findings, checkServices(name, job)...)
+	findings = append(findings, checkRulesGlobs(name, job)...)
+	findings = append(findings, checkTimeout(name, job)...)
+	findings = append(findings, checkIDTokens(name, job)...)
+	findings = append(findings, checkSecrets(name, job)...)
+	findings = append(findings, checkPagesKeyword(name, job)...)
+	findings = append(findings, checkCacheKeyFiles(name, job)...)
 	return findings
 }
 
@@ -105,6 +122,7 @@ func checkWhen(name string, job model.Job) []Finding {
 	if job.When != "" && !validJobWhen[job.When] {
 		findings = append(findings, Finding{
 			Severity: Error,
+			Rule:     RuleInvalidWhen,
 			Job:      name,
 			Message:  fmt.Sprintf("'when' has invalid value %q; valid: on_success, on_failure, always, manual, delayed, never", job.When),
 		})
@@ -112,6 +130,7 @@ func checkWhen(name string, job model.Job) []Finding {
 	if job.When == "delayed" && job.StartIn == "" {
 		findings = append(findings, Finding{
 			Severity: Error,
+			Rule:     RuleDelayedNoStartIn,
 			Job:      name,
 			Message:  "'when: delayed' requires 'start_in' (e.g. 'start_in: 30 minutes')",
 		})
@@ -119,6 +138,7 @@ func checkWhen(name string, job model.Job) []Finding {
 	if job.When != "delayed" && job.StartIn != "" {
 		findings = append(findings, Finding{
 			Severity: Error,
+			Rule:     RuleStartInNoDelayed,
 			Job:      name,
 			Message:  "'start_in' is only valid when 'when: delayed'",
 		})
@@ -135,6 +155,7 @@ func checkParallel(name string, job model.Job) []Finding {
 		if v < 2 || v > 200 {
 			return []Finding{{
 				Severity: Error,
+				Rule:     RuleInvalidParallel,
 				Job:      name,
 				Message:  fmt.Sprintf("'parallel' must be between 2 and 200, got %d", v),
 			}}
@@ -143,6 +164,7 @@ func checkParallel(name string, job model.Job) []Finding {
 		if _, ok := v["matrix"]; !ok {
 			return []Finding{{
 				Severity: Error,
+				Rule:     RuleInvalidParallel,
 				Job:      name,
 				Message:  "'parallel' map form must have a 'matrix' key",
 			}}
@@ -150,6 +172,7 @@ func checkParallel(name string, job model.Job) []Finding {
 	default:
 		return []Finding{{
 			Severity: Error,
+			Rule:     RuleInvalidParallel,
 			Job:      name,
 			Message:  "'parallel' must be an integer (2–200) or a map with 'matrix'",
 		}}
@@ -166,6 +189,7 @@ func checkRetry(name string, job model.Job) []Finding {
 		if v < 0 || v > 2 {
 			return []Finding{{
 				Severity: Error,
+				Rule:     RuleInvalidRetry,
 				Job:      name,
 				Message:  fmt.Sprintf("'retry' must be 0, 1, or 2; got %d", v),
 			}}
@@ -176,6 +200,7 @@ func checkRetry(name string, job model.Job) []Finding {
 			if n, ok := maxVal.(int); ok && (n < 0 || n > 2) {
 				findings = append(findings, Finding{
 					Severity: Error,
+					Rule:     RuleInvalidRetry,
 					Job:      name,
 					Message:  fmt.Sprintf("'retry.max' must be 0, 1, or 2; got %d", n),
 				})
@@ -188,6 +213,7 @@ func checkRetry(name string, job model.Job) []Finding {
 	default:
 		return []Finding{{
 			Severity: Error,
+			Rule:     RuleInvalidRetry,
 			Job:      name,
 			Message:  "'retry' must be an integer (0–2) or a map with 'max'/'when'",
 		}}
@@ -201,6 +227,7 @@ func validateRetryWhen(name string, val any) []Finding {
 		if !validRetryWhen[s] {
 			findings = append(findings, Finding{
 				Severity: Error,
+				Rule:     RuleInvalidRetryWhen,
 				Job:      name,
 				Message:  fmt.Sprintf("'retry.when' has invalid value %q", s),
 			})
@@ -230,6 +257,7 @@ func checkAllowFailure(name string, job model.Job) []Finding {
 		if _, ok := v["exit_codes"]; !ok {
 			return []Finding{{
 				Severity: Error,
+				Rule:     RuleInvalidAllowFailure,
 				Job:      name,
 				Message:  "'allow_failure' map form must contain 'exit_codes'",
 			}}
@@ -238,6 +266,7 @@ func checkAllowFailure(name string, job model.Job) []Finding {
 		_ = v
 		return []Finding{{
 			Severity: Error,
+			Rule:     RuleInvalidAllowFailure,
 			Job:      name,
 			Message:  "'allow_failure' must be a boolean or a map with 'exit_codes'",
 		}}
@@ -252,6 +281,7 @@ func checkInterruptible(name string, job model.Job) []Finding {
 	if _, ok := job.Interruptible.(bool); !ok {
 		return []Finding{{
 			Severity: Error,
+			Rule:     RuleInvalidInterruptible,
 			Job:      name,
 			Message:  "'interruptible' must be a boolean",
 		}}
@@ -267,6 +297,7 @@ func checkTrigger(name string, job model.Job) []Finding {
 	if scriptNonEmpty(job.Script) {
 		findings = append(findings, Finding{
 			Severity: Error,
+			Rule:     RuleTriggerWithScript,
 			Job:      name,
 			Message:  "jobs with 'trigger' cannot use 'script'",
 		})
@@ -277,6 +308,7 @@ func checkTrigger(name string, job model.Job) []Finding {
 		if !hasProject && !hasInclude {
 			findings = append(findings, Finding{
 				Severity: Error,
+				Rule:     RuleInvalidTrigger,
 				Job:      name,
 				Message:  "'trigger' map must specify 'project' or 'include'",
 			})
@@ -294,6 +326,7 @@ func checkCoverage(name string, job model.Job) []Finding {
 	if !coveragePattern.MatchString(job.Coverage) {
 		return []Finding{{
 			Severity: Error,
+			Rule:     RuleInvalidCoverage,
 			Job:      name,
 			Message:  fmt.Sprintf("'coverage' must be a regex pattern wrapped in '/' (e.g. '/\\d+\\.?\\d*%%/'), got %q", job.Coverage),
 		}}
@@ -309,6 +342,7 @@ func checkRelease(name string, job model.Job) []Finding {
 	if !ok {
 		return []Finding{{
 			Severity: Error,
+			Rule:     RuleInvalidRelease,
 			Job:      name,
 			Message:  "'release' must be a map",
 		}}
@@ -317,6 +351,7 @@ func checkRelease(name string, job model.Job) []Finding {
 	if !exists || tagName == "" || tagName == nil {
 		return []Finding{{
 			Severity: Error,
+			Rule:     RuleInvalidRelease,
 			Job:      name,
 			Message:  "'release' requires 'tag_name'",
 		}}
@@ -334,11 +369,12 @@ func checkEnvironment(name string, job model.Job) []Finding {
 		return nil
 	}
 	var findings []Finding
-	envName, _ := m["name"]
+	envName := m["name"]
 	_, hasURL := m["url"]
 	if (envName == nil || envName == "") && hasURL {
 		findings = append(findings, Finding{
 			Severity: Error,
+			Rule:     RuleInvalidEnvironment,
 			Job:      name,
 			Message:  "'environment.url' requires 'environment.name' to be set",
 		})
@@ -346,6 +382,7 @@ func checkEnvironment(name string, job model.Job) []Finding {
 	if action, ok := m["action"].(string); ok && !validEnvironmentAction[action] {
 		findings = append(findings, Finding{
 			Severity: Error,
+			Rule:     RuleInvalidEnvironment,
 			Job:      name,
 			Message:  fmt.Sprintf("'environment.action' has invalid value %q; valid: start, stop, prepare, verify, access", action),
 		})
@@ -365,22 +402,25 @@ func checkArtifacts(name string, job model.Job) []Finding {
 	if w, ok := m["when"].(string); ok && !validArtifactsWhen[w] {
 		findings = append(findings, Finding{
 			Severity: Error,
+			Rule:     RuleInvalidArtifacts,
 			Job:      name,
 			Message:  fmt.Sprintf("'artifacts.when' has invalid value %q; valid: on_success, on_failure, always", w),
 		})
 	}
 	if _, hasExposeAs := m["expose_as"]; hasExposeAs {
-		paths, _ := m["paths"]
+		paths := m["paths"]
 		if paths == nil {
 			findings = append(findings, Finding{
 				Severity: Error,
+				Rule:     RuleInvalidArtifacts,
 				Job:      name,
 				Message:  "'artifacts.expose_as' requires 'artifacts.paths'",
 			})
 		}
 	}
-	// Pages job should publish to public/
-	if name == "pages" {
+	// Pages job should publish to public/. Skip when pages: keyword is set;
+	// GL039 (checkPagesKeyword) handles that case with a more precise check.
+	if name == "pages" && job.Pages == nil {
 		if paths, ok := m["paths"].([]any); ok {
 			found := false
 			for _, p := range paths {
@@ -392,6 +432,7 @@ func checkArtifacts(name string, job model.Job) []Finding {
 			if !found {
 				findings = append(findings, Finding{
 					Severity: Warning,
+					Rule:     RulePagesPublic,
 					Job:      name,
 					Message:  "the 'pages' job should include 'public' in 'artifacts.paths' for GitLab Pages to deploy",
 				})
@@ -421,6 +462,7 @@ func checkCache(name string, job model.Job) []Finding {
 		if w, ok := m["when"].(string); ok && !validCacheWhen[w] {
 			findings = append(findings, Finding{
 				Severity: Error,
+				Rule:     RuleInvalidCache,
 				Job:      name,
 				Message:  fmt.Sprintf("'cache.when' has invalid value %q; valid: on_success, on_failure, always", w),
 			})
@@ -428,6 +470,7 @@ func checkCache(name string, job model.Job) []Finding {
 		if p, ok := m["policy"].(string); ok && !validCachePolicy[p] {
 			findings = append(findings, Finding{
 				Severity: Error,
+				Rule:     RuleInvalidCache,
 				Job:      name,
 				Message:  fmt.Sprintf("'cache.policy' has invalid value %q; valid: pull, push, pull-push", p),
 			})
@@ -442,6 +485,7 @@ func checkRules(name string, job model.Job) []Finding {
 		if rule.When != "" && !validRuleWhen[rule.When] {
 			findings = append(findings, Finding{
 				Severity: Error,
+				Rule:     RuleInvalidRulesWhen,
 				Job:      name,
 				Message:  fmt.Sprintf("rules[%d].when has invalid value %q; valid: on_success, on_failure, always, manual, delayed, never", i, rule.When),
 			})
@@ -450,6 +494,28 @@ func checkRules(name string, job model.Job) []Finding {
 	return findings
 }
 
+// checkDeadRules reports when every rule in a job's rules: block has an
+// explicit when: never, making the job permanently unreachable. This is a
+// provably-correct static claim: no matter which if: condition matches, the
+// outcome is always "never"; and if no rule matches, the implicit fallback is
+// also skip. No if: evaluation is required.
+func checkDeadRules(name string, job model.Job) []Finding {
+	if len(job.Rules) == 0 {
+		return nil
+	}
+	for _, r := range job.Rules {
+		if r.When != "never" {
+			return nil
+		}
+	}
+	return []Finding{{
+		Severity: Warning,
+		Rule:     RuleDeadRules,
+		Job:      name,
+		Message:  "rules: block can never activate; every rule has 'when: never' — job is permanently excluded from the pipeline",
+	}}
+}
+
 func checkImage(name string, job model.Job) []Finding {
 	if job.Image == nil {
 		return nil
@@ -458,10 +524,11 @@ func checkImage(name string, job model.Job) []Finding {
 	if !ok {
 		return nil // String form is valid.
 	}
-	imgName, _ := m["name"]
+	imgName := m["name"]
 	if imgName == nil || imgName == "" {
 		return []Finding{{
 			Severity: Error,
+			Rule:     RuleInvalidImage,
 			Job:      name,
 			Message:  "'image' map form requires a 'name' key",
 		}}
@@ -489,6 +556,7 @@ func checkInherit(name string, job model.Job) []Finding {
 		default:
 			findings = append(findings, Finding{
 				Severity: Error,
+				Rule:     RuleInvalidInherit,
 				Job:      name,
 				Message:  fmt.Sprintf("'inherit.%s' must be a boolean or a list of names", key),
 			})
@@ -496,3 +564,289 @@ func checkInherit(name string, job model.Job) []Finding {
 	}
 	return findings
 }
+
+// GL034: services: map form requires 'name'; 'alias' must be a valid DNS label.
+func checkServices(name string, job model.Job) []Finding {
+	if len(job.Services) == 0 {
+		return nil
+	}
+	var findings []Finding
+	for i, svc := range job.Services {
+		m, ok := svc.(map[string]any)
+		if !ok {
+			continue // string form is valid
+		}
+		n := m["name"]
+		if n == nil || n == "" {
+			findings = append(findings, Finding{
+				Severity: Error,
+				Rule:     RuleInvalidService,
+				Job:      name,
+				Message:  fmt.Sprintf("services[%d]: map form requires a 'name' key", i),
+			})
+		}
+		if alias, ok := m["alias"].(string); ok && alias != "" {
+			if !dnsLabelPattern.MatchString(alias) {
+				findings = append(findings, Finding{
+					Severity: Error,
+					Rule:     RuleInvalidService,
+					Job:      name,
+					Message:  fmt.Sprintf("services[%d]: alias %q is not a valid DNS label (only letters, digits, hyphens, and dots; must start and end with alphanumeric)", i, alias),
+				})
+			}
+		}
+	}
+	return findings
+}
+
+// GL035: rules:changes and rules:exists paths must not be absolute.
+func checkRulesGlobs(name string, job model.Job) []Finding {
+	var findings []Finding
+	for i, rule := range job.Rules {
+		findings = append(findings, checkAbsolutePaths(name, fmt.Sprintf("rules[%d].changes", i), rule.Changes)...)
+		findings = append(findings, checkAbsolutePaths(name, fmt.Sprintf("rules[%d].exists", i), rule.Exists)...)
+	}
+	return findings
+}
+
+func checkAbsolutePaths(name, field string, val any) []Finding {
+	var paths []string
+	switch v := val.(type) {
+	case []any:
+		for _, item := range v {
+			if s, ok := item.(string); ok {
+				paths = append(paths, s)
+			}
+		}
+	case map[string]any:
+		if ps, ok := v["paths"].([]any); ok {
+			for _, item := range ps {
+				if s, ok := item.(string); ok {
+					paths = append(paths, s)
+				}
+			}
+		}
+	}
+	var findings []Finding
+	for _, p := range paths {
+		if strings.HasPrefix(p, "/") {
+			findings = append(findings, Finding{
+				Severity: Warning,
+				Rule:     RuleAbsoluteGlobPath,
+				Job:      name,
+				Message:  fmt.Sprintf("%s: path %q is absolute; GitLab CI paths are relative to the repository root — absolute paths will never match", field, p),
+			})
+		}
+	}
+	return findings
+}
+
+// GL036: timeout: must be a valid GitLab CI duration string.
+func checkTimeout(name string, job model.Job) []Finding {
+	if job.Timeout == "" {
+		return nil
+	}
+	if !timeoutPattern.MatchString(job.Timeout) {
+		return []Finding{{
+			Severity: Error,
+			Rule:     RuleInvalidTimeout,
+			Job:      name,
+			Message:  fmt.Sprintf("'timeout' has invalid value %q; expected a duration like '1h 30m', '90 minutes', '2 hours'", job.Timeout),
+		}}
+	}
+	return nil
+}
+
+// CheckDefaultTimeout validates the pipeline-level default: timeout: field.
+// Exported so it can be called from linter.go.
+func checkDefaultTimeout(timeout, file string) []Finding {
+	if timeout == "" {
+		return nil
+	}
+	if !timeoutPattern.MatchString(timeout) {
+		return []Finding{{
+			Severity: Error,
+			Rule:     RuleInvalidTimeout,
+			File:     file,
+			Message:  fmt.Sprintf("'default.timeout' has invalid value %q; expected a duration like '1h 30m', '90 minutes', '2 hours'", timeout),
+		}}
+	}
+	return nil
+}
+
+// GL037: id_tokens: each entry must have an 'aud' key.
+func checkIDTokens(name string, job model.Job) []Finding {
+	if job.IDTokens == nil {
+		return nil
+	}
+	m, ok := job.IDTokens.(map[string]any)
+	if !ok {
+		return nil
+	}
+	var findings []Finding
+	for tokenName, tokenVal := range m {
+		tokenMap, ok := tokenVal.(map[string]any)
+		if !ok {
+			findings = append(findings, Finding{
+				Severity: Error,
+				Rule:     RuleInvalidIDToken,
+				Job:      name,
+				Message:  fmt.Sprintf("id_tokens.%s: must be a map with an 'aud' key", tokenName),
+			})
+			continue
+		}
+		if _, hasAud := tokenMap["aud"]; !hasAud {
+			findings = append(findings, Finding{
+				Severity: Error,
+				Rule:     RuleInvalidIDToken,
+				Job:      name,
+				Message:  fmt.Sprintf("id_tokens.%s: missing required 'aud' key", tokenName),
+			})
+		}
+	}
+	return findings
+}
+
+// GL038: secrets: each entry must have a provider key (vault, gcp_secret_manager, azure_key_vault).
+func checkSecrets(name string, job model.Job) []Finding {
+	if job.Secrets == nil {
+		return nil
+	}
+	m, ok := job.Secrets.(map[string]any)
+	if !ok {
+		return nil
+	}
+	validProviders := []string{"vault", "gcp_secret_manager", "azure_key_vault"}
+	var findings []Finding
+	for secretName, secretVal := range m {
+		secretMap, ok := secretVal.(map[string]any)
+		if !ok {
+			findings = append(findings, Finding{
+				Severity: Error,
+				Rule:     RuleInvalidSecret,
+				Job:      name,
+				Message:  fmt.Sprintf("secrets.%s: must be a map with a provider key (vault, gcp_secret_manager, or azure_key_vault)", secretName),
+			})
+			continue
+		}
+		hasProvider := false
+		for _, provider := range validProviders {
+			if _, ok := secretMap[provider]; ok {
+				hasProvider = true
+				break
+			}
+		}
+		if !hasProvider {
+			findings = append(findings, Finding{
+				Severity: Error,
+				Rule:     RuleInvalidSecret,
+				Job:      name,
+				Message:  fmt.Sprintf("secrets.%s: missing provider key; must include one of: vault, gcp_secret_manager, azure_key_vault", secretName),
+			})
+		}
+	}
+	return findings
+}
+
+// GL039: a job with the pages: keyword must have the publish directory in artifacts.paths.
+func checkPagesKeyword(name string, job model.Job) []Finding {
+	if job.Pages == nil {
+		return nil
+	}
+	publishDir := "public"
+	if m, ok := job.Pages.(map[string]any); ok {
+		if p, ok := m["publish"].(string); ok && p != "" {
+			publishDir = p
+		}
+	}
+	if job.Artifacts == nil {
+		return []Finding{{
+			Severity: Warning,
+			Rule:     RulePagesPublish,
+			Job:      name,
+			Message:  fmt.Sprintf("job uses 'pages:' keyword with publish dir %q but has no 'artifacts:' block — GitLab Pages will not deploy", publishDir),
+		}}
+	}
+	m, ok := job.Artifacts.(map[string]any)
+	if !ok {
+		return nil
+	}
+	paths, ok := m["paths"].([]any)
+	if !ok || len(paths) == 0 {
+		return []Finding{{
+			Severity: Warning,
+			Rule:     RulePagesPublish,
+			Job:      name,
+			Message:  fmt.Sprintf("job uses 'pages:' keyword with publish dir %q but 'artifacts.paths' is missing — GitLab Pages will not deploy", publishDir),
+		}}
+	}
+	for _, p := range paths {
+		if s, ok := p.(string); ok && (s == publishDir || strings.HasPrefix(s, publishDir+"/")) {
+			return nil
+		}
+	}
+	return []Finding{{
+		Severity: Warning,
+		Rule:     RulePagesPublish,
+		Job:      name,
+		Message:  fmt.Sprintf("'pages.publish' is %q but 'artifacts.paths' does not include it — GitLab Pages will not deploy", publishDir),
+	}}
+}
+
+// GL041: cache.key.files must be a list of exact file paths, not glob patterns.
+func checkCacheKeyFiles(name string, job model.Job) []Finding {
+	if job.Cache == nil {
+		return nil
+	}
+	var maps []map[string]any
+	switch v := job.Cache.(type) {
+	case map[string]any:
+		maps = []map[string]any{v}
+	case []any:
+		for _, item := range v {
+			if m, ok := item.(map[string]any); ok {
+				maps = append(maps, m)
+			}
+		}
+	}
+	var findings []Finding
+	for _, m := range maps {
+		keyVal, ok := m["key"]
+		if !ok {
+			continue
+		}
+		keyMap, ok := keyVal.(map[string]any)
+		if !ok {
+			continue
+		}
+		filesVal, ok := keyMap["files"]
+		if !ok {
+			continue
+		}
+		filesList, ok := filesVal.([]any)
+		if !ok {
+			findings = append(findings, Finding{
+				Severity: Error,
+				Rule:     RuleInvalidCacheKeyFiles,
+				Job:      name,
+				Message:  "'cache.key.files' must be a list of file paths",
+			})
+			continue
+		}
+		for _, item := range filesList {
+			s, ok := item.(string)
+			if !ok {
+				continue
+			}
+			if strings.ContainsAny(s, "*?[") {
+				findings = append(findings, Finding{
+					Severity: Warning,
+					Rule:     RuleInvalidCacheKeyFiles,
+					Job:      name,
+					Message:  fmt.Sprintf("cache.key.files: %q looks like a glob pattern; 'key.files' must be exact file paths, not globs", s),
+				})
+			}
+		}
+	}
+	return findings
+}

internal/linter/linter.go

@@ -1,7 +1,9 @@
 package linter
 
 import (
+	"cmp"
 	"fmt"
+	"slices"
 	"strings"
 
 	"git.k3nny.fr/glint/internal/model"
@@ -16,6 +18,7 @@ const (
 
 type Finding struct {
 	Severity Severity
+	Rule     string // stable rule ID, e.g. "GL003" — see rules.go
 	Job      string // empty for pipeline-level findings
 	File     string // source file where the finding originates
 	Line     int    // line number in File (0 = unknown)
@@ -23,31 +26,53 @@ type Finding struct {
 }
 
 func (f Finding) String() string {
-	loc := ""
+	var loc string
 	if f.File != "" {
 		if f.Line > 0 {
-			loc = fmt.Sprintf(" (%s:%d)", f.File, f.Line)
+			loc = fmt.Sprintf("%s:%d: ", f.File, f.Line)
 		} else {
-			loc = fmt.Sprintf(" (%s)", f.File)
+			loc = fmt.Sprintf("%s: ", f.File)
 		}
 	}
-	if f.Job != "" {
-		return fmt.Sprintf("[%s] job %q%s: %s", f.Severity, f.Job, loc, f.Message)
-	}
-	if loc != "" {
-		return fmt.Sprintf("[%s]%s: %s", f.Severity, loc, f.Message)
-	}
-	return fmt.Sprintf("[%s] %s", f.Severity, f.Message)
-}
 
-// Lint runs all rules against p and returns findings sorted by job name.
+	rule := ""
+	if f.Rule != "" {
+		rule = f.Rule + " "
+	}
+
+	sev := "[" + strings.ToLower(string(f.Severity)) + "]"
+
+	msg := f.Message
+	if f.Job != "" {
+		msg = fmt.Sprintf("job %q: %s", f.Job, f.Message)
+	}
+
+	return fmt.Sprintf("%s%s%s %s", loc, rule, sev, msg)
+}
+
+// Lint runs all rules against p and returns findings sorted by (File, Line, Rule).
+// Findings with no File (pipeline-level) sort before file-scoped ones.
 func Lint(p *model.Pipeline) []Finding {
 	var findings []Finding
 	findings = append(findings, checkStages(p)...)
+	findings = append(findings, checkDuplicateStages(p)...)
+	findings = append(findings, checkDefault(p)...)
 	findings = append(findings, checkWorkflow(p)...)
 	findings = append(findings, checkJobs(p)...)
 	findings = append(findings, checkNeeds(p)...)
 	findings = append(findings, checkDependencies(p)...)
+	findings = append(findings, checkVariableRefs(p)...)
+	findings = append(findings, checkRulesIfReachability(p)...)
+	findings = append(findings, checkInheritCompleteness(p)...)
+	slices.SortStableFunc(findings, func(a, b Finding) int {
+		if c := cmp.Compare(a.File, b.File); c != 0 {
+			return c
+		}
+		if c := cmp.Compare(a.Line, b.Line); c != 0 {
+			return c
+		}
+		return cmp.Compare(a.Rule, b.Rule)
+	})
 	return findings
 }
 
@@ -56,6 +81,7 @@ func checkStages(p *model.Pipeline) []Finding {
 	if len(p.Stages) == 0 {
 		findings = append(findings, Finding{
 			Severity: Warning,
+			Rule:     RuleNoStages,
 			File:     p.SourceFile,
 			Message:  "no stages defined; GitLab will use default stages (build, test, deploy)",
 		})
@@ -63,6 +89,32 @@ func checkStages(p *model.Pipeline) []Finding {
 	return findings
 }
 
+// GL040: warn when a stage name appears more than once in stages:.
+func checkDuplicateStages(p *model.Pipeline) []Finding {
+	seen := make(map[string]bool, len(p.Stages))
+	var findings []Finding
+	for _, s := range p.Stages {
+		if seen[s] {
+			findings = append(findings, Finding{
+				Severity: Warning,
+				Rule:     RuleDuplicateStage,
+				File:     p.SourceFile,
+				Message:  fmt.Sprintf("stage %q appears more than once in 'stages'; GitLab silently merges duplicate stage entries", s),
+			})
+		}
+		seen[s] = true
+	}
+	return findings
+}
+
+// checkDefault validates the pipeline-level default: block.
+func checkDefault(p *model.Pipeline) []Finding {
+	if p.Default == nil {
+		return nil
+	}
+	return checkDefaultTimeout(p.Default.Timeout, p.SourceFile)
+}
+
 func checkWorkflow(p *model.Pipeline) []Finding {
 	if p.Workflow == nil {
 		return nil
@@ -72,6 +124,7 @@ func checkWorkflow(p *model.Pipeline) []Finding {
 		if rule.When != "" && !validWorkflowRuleWhen[rule.When] {
 			findings = append(findings, Finding{
 				Severity: Error,
+				Rule:     RuleWorkflowWhen,
 				File:     p.SourceFile,
 				Message:  fmt.Sprintf("workflow.rules[%d].when has invalid value %q; valid: always, never", i, rule.When),
 			})
@@ -113,6 +166,7 @@ func checkJob(name string, job model.Job, stageSet map[string]bool) []Finding {
 		}
 		findings = append(findings, Finding{
 			Severity: sev,
+			Rule:     RuleMissingScript,
 			Job:      name,
 			Message:  "missing required field 'script' (or 'run')",
 		})
@@ -124,6 +178,7 @@ func checkJob(name string, job model.Job, stageSet map[string]bool) []Finding {
 	if job.Stage != "" && !strings.Contains(job.Stage, "$[[") && len(stageSet) > 0 && !stageSet[job.Stage] {
 		findings = append(findings, Finding{
 			Severity: Error,
+			Rule:     RuleUnknownStage,
 			Job:      name,
 			Message:  fmt.Sprintf("stage %q is not defined in 'stages'", job.Stage),
 		})
@@ -133,6 +188,7 @@ func checkJob(name string, job model.Job, stageSet map[string]bool) []Finding {
 	if job.Only != nil && len(job.Rules) > 0 {
 		findings = append(findings, Finding{
 			Severity: Error,
+			Rule:     RuleOnlyRulesConflict,
 			Job:      name,
 			Message:  "'only' and 'rules' cannot be used together",
 		})
@@ -142,6 +198,7 @@ func checkJob(name string, job model.Job, stageSet map[string]bool) []Finding {
 	if job.Except != nil && len(job.Rules) > 0 {
 		findings = append(findings, Finding{
 			Severity: Error,
+			Rule:     RuleExceptRulesConflict,
 			Job:      name,
 			Message:  "'except' and 'rules' cannot be used together",
 		})
@@ -151,6 +208,7 @@ func checkJob(name string, job model.Job, stageSet map[string]bool) []Finding {
 	if job.Only != nil || job.Except != nil {
 		findings = append(findings, Finding{
 			Severity: Warning,
+			Rule:     RuleDeprecatedOnly,
 			Job:      name,
 			Message:  "'only'/'except' are deprecated; prefer 'rules'",
 		})

internal/linter/needs.go

@@ -46,6 +46,7 @@ func checkNeeds(p *model.Pipeline) []Finding {
 				}
 				findings = append(findings, Finding{
 					Severity: sev,
+					Rule:     RuleNeedsUnknown,
 					Job:      name,
 					File:     job.File,
 					Line:     job.Line,
@@ -63,6 +64,7 @@ func checkNeeds(p *model.Pipeline) []Finding {
 				if neededHasStage && neededStageIdx > jobStageIdx {
 					findings = append(findings, Finding{
 						Severity: Error,
+						Rule:     RuleNeedsStageOrder,
 						Job:      name,
 						File:     job.File,
 						Line:     job.Line,
@@ -124,6 +126,7 @@ func detectNeedsCycles(graph map[string][]string, jobs map[string]model.Job) []F
 				j := jobs[name]
 				findings = append(findings, Finding{
 					Severity: Error,
+					Rule:     RuleNeedsCycle,
 					Job:      name,
 					File:     j.File,
 					Line:     j.Line,

internal/linter/rules.go

@@ -0,0 +1,157 @@
+package linter
+
+// Rule ID constants. Each ID is stable across versions and uniquely identifies
+// one lint check. Use these when filtering output, writing suppression rules,
+// or referencing a check in documentation.
+//
+// Prefix GL = Glint / GitLab CI lint.
+// Numbering is sequential by category; gaps may appear as rules are added.
+const (
+	// ── Pipeline-level ──────────────────────────────────────────────────────
+
+	// GL001: no stages: block defined; GitLab falls back to default stages.
+	RuleNoStages = "GL001"
+
+	// GL002: workflow.rules[n].when has an invalid value (only always/never allowed).
+	RuleWorkflowWhen = "GL002"
+
+	// ── Job structure ────────────────────────────────────────────────────────
+
+	// GL003: job is missing a required script: (or run:) field.
+	RuleMissingScript = "GL003"
+
+	// GL004: job references a stage not declared in stages:.
+	RuleUnknownStage = "GL004"
+
+	// GL005: only: and rules: used together on the same job.
+	RuleOnlyRulesConflict = "GL005"
+
+	// GL006: except: and rules: used together on the same job.
+	RuleExceptRulesConflict = "GL006"
+
+	// GL007: only:/except: used (deprecated; prefer rules:).
+	RuleDeprecatedOnly = "GL007"
+
+	// ── Keyword constraints ──────────────────────────────────────────────────
+
+	// GL008: when: has an invalid value.
+	RuleInvalidWhen = "GL008"
+
+	// GL009: when: delayed without start_in:.
+	RuleDelayedNoStartIn = "GL009"
+
+	// GL010: start_in: set when when: is not delayed.
+	RuleStartInNoDelayed = "GL010"
+
+	// GL011: parallel: value is invalid (integer out of range or map missing matrix:).
+	RuleInvalidParallel = "GL011"
+
+	// GL012: retry: integer is out of range 0–2, or retry: is neither int nor map.
+	RuleInvalidRetry = "GL012"
+
+	// GL013: retry.when: contains an unrecognised failure type.
+	RuleInvalidRetryWhen = "GL013"
+
+	// GL014: allow_failure: is not a boolean or a map with exit_codes:.
+	RuleInvalidAllowFailure = "GL014"
+
+	// GL015: interruptible: is not a boolean.
+	RuleInvalidInterruptible = "GL015"
+
+	// GL016: trigger: job also defines script: (mutually exclusive).
+	RuleTriggerWithScript = "GL016"
+
+	// GL017: trigger: map does not specify project: or include:.
+	RuleInvalidTrigger = "GL017"
+
+	// GL018: coverage: is not a regex pattern wrapped in /.
+	RuleInvalidCoverage = "GL018"
+
+	// GL019: release: is missing required tag_name:, or is not a map.
+	RuleInvalidRelease = "GL019"
+
+	// GL020: environment: has an invalid url/action configuration.
+	RuleInvalidEnvironment = "GL020"
+
+	// GL021: artifacts: has an invalid when/expose_as configuration.
+	RuleInvalidArtifacts = "GL021"
+
+	// GL022: pages job artifacts.paths does not include public/.
+	RulePagesPublic = "GL022"
+
+	// GL023: cache: has an invalid when/policy value.
+	RuleInvalidCache = "GL023"
+
+	// GL024: rules[n].when has an invalid value.
+	RuleInvalidRulesWhen = "GL024"
+
+	// GL025: image: map form is missing a name: key.
+	RuleInvalidImage = "GL025"
+
+	// GL026: inherit.default or inherit.variables is not a boolean or list.
+	RuleInvalidInherit = "GL026"
+
+	// ── Cross-job graph ──────────────────────────────────────────────────────
+
+	// GL027: needs: references a job that does not exist in the pipeline.
+	RuleNeedsUnknown = "GL027"
+
+	// GL028: needs: references a job in a later stage than the current job.
+	RuleNeedsStageOrder = "GL028"
+
+	// GL029: circular dependency detected in the needs: graph.
+	RuleNeedsCycle = "GL029"
+
+	// GL030: dependencies: references a job that does not exist.
+	RuleUnknownDependency = "GL030"
+
+	// GL031: dependencies: references a job in the same or a later stage.
+	RuleDependencyStage = "GL031"
+
+	// ── Expression validation ────────────────────────────────────────────────
+
+	// GL032: rules:if: references a variable not declared in pipeline variables:,
+	// the job's own variables:, or any workflow:rules:variables: block.
+	// May be a false positive for variables set in GitLab CI/CD project settings.
+	RuleUndeclaredVariable = "GL032"
+
+	// GL033: every rule in a job's rules: block has when: never, so the job
+	// can never be included in any pipeline run.
+	RuleDeadRules = "GL033"
+
+	// GL034: services: map form is missing 'name', or 'alias' is not a valid DNS label.
+	RuleInvalidService = "GL034"
+
+	// GL035: rules:changes or rules:exists contains an absolute path (starts with /);
+	// GitLab CI paths are relative to the repository root and absolute paths never match.
+	RuleAbsoluteGlobPath = "GL035"
+
+	// GL036: timeout: is not a valid GitLab CI duration string (e.g. '1h 30m', '90 minutes').
+	RuleInvalidTimeout = "GL036"
+
+	// GL037: id_tokens: entry is missing the required 'aud' key.
+	RuleInvalidIDToken = "GL037"
+
+	// GL038: secrets: entry is missing a provider key (vault, gcp_secret_manager, or azure_key_vault).
+	RuleInvalidSecret = "GL038"
+
+	// GL039: a job has the pages: keyword but artifacts.paths does not include the publish directory.
+	RulePagesPublish = "GL039"
+
+	// GL040: a stage name appears more than once in stages:; GitLab silently merges duplicates.
+	RuleDuplicateStage = "GL040"
+
+	// GL041: cache.key.files contains a glob pattern; it must be a list of exact file paths.
+	RuleInvalidCacheKeyFiles = "GL041"
+
+	// GL042: every rules:if: condition in a job's rules: block evaluates to false
+	// given the values of variables declared in the pipeline YAML, so the job can
+	// never be active. Only fires when all referenced variables are declared
+	// (predefined CI_* / GITLAB_* vars are not evaluated to avoid false positives).
+	RuleStaticDeadRules = "GL042"
+
+	// GL043: a job declares 'inherit: default:' (true, false, or list) but the
+	// pipeline has no 'default:' block, making the declaration a no-op. Also fires
+	// when 'inherit: default: [list]' names fields not set in the default: block.
+	RuleInheritNoDefault = "GL043"
+)

internal/linter/samba_test.go

@@ -14,7 +14,7 @@ import (
 // pipeline that is valid on GitLab) produces no Error findings.
 // These files exercise local include resolution and multi-level extends chains.
 func TestSambaCI(t *testing.T) {
-	entryPoint := "../../samba-testdata/.gitlab-ci.yml"
+	entryPoint := "../../testdata/samba/.gitlab-ci.yml"
 
 	p, err := model.Parse(entryPoint)
 	if err != nil {
@@ -51,9 +51,9 @@ func TestSambaCIEntryFiles(t *testing.T) {
 		name string
 		path string
 	}{
-		{"default", "../../samba-testdata/.gitlab-ci.yml"},
-		{"coverage", "../../samba-testdata/.gitlab-ci-coverage.yml"},
-		{"private", "../../samba-testdata/.gitlab-ci-private.yml"},
+		{"default", "../../testdata/samba/.gitlab-ci.yml"},
+		{"coverage", "../../testdata/samba/.gitlab-ci-coverage.yml"},
+		{"private", "../../testdata/samba/.gitlab-ci-private.yml"},
 	}
 
 	for _, tc := range entryPoints {

internal/linter/variables.go

@@ -0,0 +1,158 @@
+package linter
+
+import (
+	"fmt"
+	"strings"
+
+	"git.k3nny.fr/glint/internal/model"
+)
+
+// predefinedVarPrefixes lists GitLab-maintained variable namespaces that are
+// always available without an explicit declaration in variables: blocks.
+var predefinedVarPrefixes = []string{
+	"CI_",      // most predefined CI variables (CI_COMMIT_BRANCH, CI_JOB_ID, …)
+	"GITLAB_",  // user/project metadata (GITLAB_USER_ID, GITLAB_FEATURES, …)
+	"FF_",      // GitLab feature flags
+	"RUNNER_",  // runner-level variables
+	"TRIGGER_", // trigger token variables passed from upstream pipelines
+	"CHAT_",    // ChatOps variables
+}
+
+func isPredefinedVar(name string) bool {
+	for _, prefix := range predefinedVarPrefixes {
+		if strings.HasPrefix(name, prefix) {
+			return true
+		}
+	}
+	return false
+}
+
+// extractIfVars returns every variable name referenced in a rules:if: expression.
+// String literals are skipped so that dollar signs inside quoted values are
+// not mistaken for variable references.
+func extractIfVars(expr string) []string {
+	var names []string
+	i := 0
+	for i < len(expr) {
+		switch expr[i] {
+		case '"', '\'':
+			quote := expr[i]
+			i++
+			for i < len(expr) && expr[i] != quote {
+				if expr[i] == '\\' {
+					i++ // skip escaped character
+				}
+				i++
+			}
+			if i < len(expr) {
+				i++ // consume closing quote
+			}
+		case '$':
+			i++ // consume '$'
+			if i < len(expr) && expr[i] == '{' {
+				i++ // consume '{'
+				start := i
+				for i < len(expr) && isVarNameByte(expr[i]) {
+					i++
+				}
+				if i < len(expr) && expr[i] == '}' && i > start {
+					names = append(names, expr[start:i])
+					i++ // consume '}'
+				}
+			} else {
+				start := i
+				for i < len(expr) && isVarNameByte(expr[i]) {
+					i++
+				}
+				if i > start {
+					names = append(names, expr[start:i])
+				}
+			}
+		default:
+			i++
+		}
+	}
+	return names
+}
+
+func isVarNameByte(b byte) bool {
+	return (b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z') || (b >= '0' && b <= '9') || b == '_'
+}
+
+// checkVariableRefs warns when a rules:if: expression references a variable that
+// is not declared in pipeline variables:, the job's own variables:, or any
+// workflow:rules:variables: block. Predefined GitLab CI variables (CI_*, GITLAB_*,
+// …) are always exempt. Variables set in GitLab CI/CD project settings are
+// invisible to glint, so the finding is a WARNING rather than an error.
+func checkVariableRefs(p *model.Pipeline) []Finding {
+	pipelineVars := make(map[string]bool, len(p.Variables))
+	for k := range p.Variables {
+		pipelineVars[k] = true
+	}
+
+	// Union of all variables any workflow rule might inject into the context.
+	workflowRuleVars := make(map[string]bool)
+	if p.Workflow != nil {
+		for _, rule := range p.Workflow.Rules {
+			for k := range rule.Variables {
+				workflowRuleVars[k] = true
+			}
+		}
+	}
+
+	var findings []Finding
+
+	// Check workflow rules:if: expressions.
+	if p.Workflow != nil {
+		seen := make(map[string]bool)
+		for i, rule := range p.Workflow.Rules {
+			if rule.If == "" {
+				continue
+			}
+			for _, varName := range extractIfVars(rule.If) {
+				if isPredefinedVar(varName) || pipelineVars[varName] || seen[varName] {
+					continue
+				}
+				seen[varName] = true
+				findings = append(findings, Finding{
+					Severity: Warning,
+					Rule:     RuleUndeclaredVariable,
+					File:     p.SourceFile,
+					Message:  fmt.Sprintf("workflow.rules[%d].if: $%s is not declared in pipeline variables:", i, varName),
+				})
+			}
+		}
+	}
+
+	// Check each job's rules:if: expressions.
+	for name, job := range p.Jobs {
+		jobVars := make(map[string]bool, len(job.Variables))
+		for k := range job.Variables {
+			jobVars[k] = true
+		}
+
+		// Deduplicate per (job, varName): report each undeclared variable once per job.
+		seen := make(map[string]bool)
+		for i, rule := range job.Rules {
+			if rule.If == "" {
+				continue
+			}
+			for _, varName := range extractIfVars(rule.If) {
+				if isPredefinedVar(varName) || pipelineVars[varName] || jobVars[varName] || workflowRuleVars[varName] || seen[varName] {
+					continue
+				}
+				seen[varName] = true
+				findings = append(findings, Finding{
+					Severity: Warning,
+					Rule:     RuleUndeclaredVariable,
+					Job:      name,
+					File:     job.File,
+					Line:     job.Line,
+					Message:  fmt.Sprintf("rules[%d].if: $%s is not declared in pipeline or job variables:", i, varName),
+				})
+			}
+		}
+	}
+
+	return findings
+}

internal/linter/variables_test.go

@@ -0,0 +1,214 @@
+package linter
+
+import (
+	"testing"
+
+	"git.k3nny.fr/glint/internal/model"
+)
+
+func TestExtractIfVars(t *testing.T) {
+	cases := []struct {
+		name string
+		expr string
+		want []string
+	}{
+		{
+			name: "simple variable",
+			expr: `$MY_VAR == "value"`,
+			want: []string{"MY_VAR"},
+		},
+		{
+			name: "curly brace syntax",
+			expr: `${MY_VAR} != null`,
+			want: []string{"MY_VAR"},
+		},
+		{
+			name: "multiple variables",
+			expr: `$BRANCH == "main" && $DEPLOY_ENV == "prod"`,
+			want: []string{"BRANCH", "DEPLOY_ENV"},
+		},
+		{
+			name: "dollar sign inside string literal is skipped",
+			expr: `$REAL_VAR == "$not_a_var"`,
+			want: []string{"REAL_VAR"},
+		},
+		{
+			name: "no variables",
+			expr: `"main" == "main"`,
+			want: nil,
+		},
+		{
+			name: "regex rhs variable",
+			expr: `$BRANCH =~ $PATTERN`,
+			want: []string{"BRANCH", "PATTERN"},
+		},
+		{
+			name: "multiline expression",
+			expr: "$BRANCH == \"main\" ||\n$BRANCH == \"develop\"",
+			want: []string{"BRANCH", "BRANCH"},
+		},
+	}
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			got := extractIfVars(tc.expr)
+			if len(got) != len(tc.want) {
+				t.Fatalf("extractIfVars(%q) = %v, want %v", tc.expr, got, tc.want)
+			}
+			for i, v := range got {
+				if v != tc.want[i] {
+					t.Errorf("[%d] got %q, want %q", i, v, tc.want[i])
+				}
+			}
+		})
+	}
+}
+
+func TestIsPredefinedVar(t *testing.T) {
+	cases := []struct {
+		input string
+		want  bool
+	}{
+		{"CI_COMMIT_BRANCH", true},
+		{"CI_JOB_TOKEN", true},
+		{"GITLAB_USER_ID", true},
+		{"GITLAB_FEATURES", true},
+		{"FF_SOME_FLAG", true},
+		{"RUNNER_ID", true},
+		{"TRIGGER_PAYLOAD", true},
+		{"CHAT_INPUT", true},
+		{"MY_CUSTOM_VAR", false},
+		{"DEPLOY_ENV", false},
+		{"FEATURE_ENABLED", false},
+	}
+	for _, tc := range cases {
+		t.Run(tc.input, func(t *testing.T) {
+			if got := isPredefinedVar(tc.input); got != tc.want {
+				t.Errorf("isPredefinedVar(%q) = %v, want %v", tc.input, got, tc.want)
+			}
+		})
+	}
+}
+
+func TestCheckVariableRefs(t *testing.T) {
+	cases := []struct {
+		name         string
+		pipeline     *model.Pipeline
+		wantWarnings int
+	}{
+		{
+			name: "declared pipeline variable — no warning",
+			pipeline: &model.Pipeline{
+				Variables: map[string]any{"MY_VAR": "value"},
+				Jobs: map[string]model.Job{
+					"job-a": {Rules: []model.Rule{{If: `$MY_VAR == "value"`}}},
+				},
+			},
+			wantWarnings: 0,
+		},
+		{
+			name: "predefined CI variable — no warning",
+			pipeline: &model.Pipeline{
+				Jobs: map[string]model.Job{
+					"job-a": {Rules: []model.Rule{{If: `$CI_COMMIT_BRANCH == "main"`}}},
+				},
+			},
+			wantWarnings: 0,
+		},
+		{
+			name: "undeclared variable — one warning",
+			pipeline: &model.Pipeline{
+				Jobs: map[string]model.Job{
+					"job-a": {Rules: []model.Rule{{If: `$UNDEFINED_VAR == "yes"`}}},
+				},
+			},
+			wantWarnings: 1,
+		},
+		{
+			name: "same undeclared var in multiple rules — one warning per job",
+			pipeline: &model.Pipeline{
+				Jobs: map[string]model.Job{
+					"job-a": {
+						Rules: []model.Rule{
+							{If: `$UNDEFINED_VAR == "yes"`},
+							{If: `$UNDEFINED_VAR == "no"`},
+						},
+					},
+				},
+			},
+			wantWarnings: 1,
+		},
+		{
+			name: "job-level variable — no warning",
+			pipeline: &model.Pipeline{
+				Jobs: map[string]model.Job{
+					"job-a": {
+						Variables: map[string]any{"LOCAL_VAR": "value"},
+						Rules:     []model.Rule{{If: `$LOCAL_VAR == "value"`}},
+					},
+				},
+			},
+			wantWarnings: 0,
+		},
+		{
+			name: "workflow rule variable available to job rules — no warning",
+			pipeline: &model.Pipeline{
+				Workflow: &model.Workflow{
+					Rules: []model.Rule{
+						{
+							If:        `$CI_COMMIT_BRANCH == "main"`,
+							Variables: map[string]any{"DEPLOY_ENV": "production"},
+						},
+					},
+				},
+				Jobs: map[string]model.Job{
+					"job-a": {Rules: []model.Rule{{If: `$DEPLOY_ENV == "production"`}}},
+				},
+			},
+			wantWarnings: 0,
+		},
+		{
+			name: "undeclared variable in workflow rules:if",
+			pipeline: &model.Pipeline{
+				Workflow: &model.Workflow{
+					Rules: []model.Rule{{If: `$UNDECLARED == "main"`}},
+				},
+				Jobs: map[string]model.Job{},
+			},
+			wantWarnings: 1,
+		},
+		{
+			name: "two jobs each with a different undeclared variable — two warnings",
+			pipeline: &model.Pipeline{
+				Jobs: map[string]model.Job{
+					"job-a": {Rules: []model.Rule{{If: `$UNDEF_A == "x"`}}},
+					"job-b": {Rules: []model.Rule{{If: `$UNDEF_B == "y"`}}},
+				},
+			},
+			wantWarnings: 2,
+		},
+		{
+			name: "no rules — no warnings",
+			pipeline: &model.Pipeline{
+				Jobs: map[string]model.Job{
+					"job-a": {Script: "echo ok"},
+				},
+			},
+			wantWarnings: 0,
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			findings := checkVariableRefs(tc.pipeline)
+			count := 0
+			for _, f := range findings {
+				if f.Severity == Warning && f.Rule == RuleUndeclaredVariable {
+					count++
+				}
+			}
+			if count != tc.wantWarnings {
+				t.Errorf("got %d GL032 warnings, want %d; findings: %v", count, tc.wantWarnings, findings)
+			}
+		})
+	}
+}

internal/model/parser.go

@@ -3,6 +3,7 @@ package model
 import (
 	"fmt"
 	"os"
+	"strings"
 
 	"gopkg.in/yaml.v3"
 )
@@ -24,6 +25,8 @@ func Parse(path string) (*Pipeline, error) {
 
 // ParseBytes parses YAML from an in-memory byte slice.
 func ParseBytes(data []byte) (*Pipeline, error) {
+	data = sanitizeYAMLEscapes(data)
+
 	// First pass: parse into a yaml.Node document to extract job keys with
 	// their exact source line numbers (key nodes carry the line, value nodes
 	// carry the body we decode into Job / map[string]any).
@@ -58,6 +61,14 @@ func ParseBytes(data []byte) (*Pipeline, error) {
 			continue
 		}
 
+		// Extract any inline suppression directive from the job's head or line comment.
+		if rules := parseSuppressComment(keyNode.HeadComment, keyNode.LineComment); len(rules) > 0 {
+			if p.Suppressions == nil {
+				p.Suppressions = map[string][]string{}
+			}
+			p.Suppressions[key] = rules
+		}
+
 		var rawMap map[string]any
 		if err := valNode.Decode(&rawMap); err != nil {
 			return nil, fmt.Errorf("parsing raw job %q: %w", key, err)
@@ -75,3 +86,96 @@ func ParseBytes(data []byte) (*Pipeline, error) {
 
 	return p, nil
 }
+
+// parseSuppressComment scans head/line comments from a YAML key node for a
+// "# glint: ignore RULE [RULE ...]" directive. Returns the list of rule IDs
+// to suppress (uppercased), or []string{"*"} for "# glint: ignore all".
+// Returns nil when no directive is found.
+func parseSuppressComment(headComment, lineComment string) []string {
+	for _, raw := range []string{headComment, lineComment} {
+		for _, line := range strings.Split(raw, "\n") {
+			line = strings.TrimLeft(line, "# \t")
+			if !strings.HasPrefix(line, "glint:") {
+				continue
+			}
+			rest := strings.TrimSpace(strings.TrimPrefix(line, "glint:"))
+			if !strings.HasPrefix(rest, "ignore") {
+				continue
+			}
+			rest = strings.TrimSpace(strings.TrimPrefix(rest, "ignore"))
+			if rest == "" || strings.EqualFold(rest, "all") {
+				return []string{"*"}
+			}
+			var rules []string
+			for _, part := range strings.FieldsFunc(rest, func(r rune) bool {
+				return r == ',' || r == ' ' || r == '\t'
+			}) {
+				if p := strings.TrimSpace(part); p != "" {
+					rules = append(rules, strings.ToUpper(p))
+				}
+			}
+			return rules
+		}
+	}
+	return nil
+}
+
+// sanitizeYAMLEscapes rewrites double-quoted YAML strings, replacing the \/
+// escape sequence (unrecognised by gopkg.in/yaml.v3) with \\/ so that the
+// parser produces a literal backslash+slash — preserving regex patterns like
+// /^us\// that appear in GitLab CI if: expressions.
+func sanitizeYAMLEscapes(data []byte) []byte {
+	type state int
+	const (
+		stOutside state = iota
+		stSingleQ
+		stDoubleQ
+		stEscape
+	)
+
+	out := make([]byte, 0, len(data))
+	s := stOutside
+
+	for i := 0; i < len(data); i++ {
+		b := data[i]
+		switch s {
+		case stOutside:
+			out = append(out, b)
+			switch b {
+			case '"':
+				s = stDoubleQ
+			case '\'':
+				s = stSingleQ
+			}
+		case stSingleQ:
+			out = append(out, b)
+			if b == '\'' {
+				if i+1 < len(data) && data[i+1] == '\'' {
+					// '' inside a single-quoted string is an escaped single-quote
+					out = append(out, data[i+1])
+					i++
+				} else {
+					s = stOutside
+				}
+			}
+		case stDoubleQ:
+			out = append(out, b)
+			switch b {
+			case '\\':
+				s = stEscape
+			case '"':
+				s = stOutside
+			}
+		case stEscape:
+			if b == '/' {
+				// \/ is not recognised by yaml.v3; rewrite as \\/ which
+				// the parser resolves to a literal backslash + slash.
+				out = append(out, '\\', '/')
+			} else {
+				out = append(out, b)
+			}
+			s = stDoubleQ
+		}
+	}
+	return out
+}

internal/model/parser_suppress_test.go

@@ -0,0 +1,125 @@
+package model
+
+import "testing"
+
+func TestParseSuppressComment(t *testing.T) {
+	cases := []struct {
+		name        string
+		head        string
+		line        string
+		wantRules   []string
+		wantNil     bool
+	}{
+		{
+			name:    "no comment",
+			head:    "",
+			line:    "",
+			wantNil: true,
+		},
+		{
+			name:      "single rule head comment",
+			head:      "# glint: ignore GL007",
+			wantRules: []string{"GL007"},
+		},
+		{
+			name:      "multiple rules comma-separated",
+			head:      "# glint: ignore GL007, GL032",
+			wantRules: []string{"GL007", "GL032"},
+		},
+		{
+			name:      "multiple rules space-separated",
+			head:      "# glint: ignore GL007 GL032",
+			wantRules: []string{"GL007", "GL032"},
+		},
+		{
+			name:      "ignore all",
+			head:      "# glint: ignore all",
+			wantRules: []string{"*"},
+		},
+		{
+			name:      "ignore all bare",
+			head:      "# glint: ignore",
+			wantRules: []string{"*"},
+		},
+		{
+			name:      "lowercase rule ID is uppercased",
+			head:      "# glint: ignore gl007",
+			wantRules: []string{"GL007"},
+		},
+		{
+			name:      "line comment",
+			head:      "",
+			line:      "# glint: ignore GL004",
+			wantRules: []string{"GL004"},
+		},
+		{
+			name:    "unrelated comment",
+			head:    "# This job deploys to production",
+			wantNil: true,
+		},
+		{
+			name:    "partial match - not a glint directive",
+			head:    "# hint: ignore this",
+			wantNil: true,
+		},
+		{
+			name:      "multi-line head comment with directive on second line",
+			head:      "# Some description\n# glint: ignore GL007",
+			wantRules: []string{"GL007"},
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			got := parseSuppressComment(tc.head, tc.line)
+			if tc.wantNil {
+				if got != nil {
+					t.Errorf("expected nil, got %v", got)
+				}
+				return
+			}
+			if len(got) != len(tc.wantRules) {
+				t.Fatalf("got %v, want %v", got, tc.wantRules)
+			}
+			for i, r := range tc.wantRules {
+				if got[i] != r {
+					t.Errorf("[%d] got %q, want %q", i, got[i], r)
+				}
+			}
+		})
+	}
+}
+
+func TestParseBytes_Suppressions(t *testing.T) {
+	yaml := `
+stages:
+  - build
+
+# glint: ignore GL007
+deprecated-job:
+  stage: build
+  only:
+    - main
+
+normal-job:
+  stage: build
+  script: echo ok
+`
+	p, err := ParseBytes([]byte(yaml))
+	if err != nil {
+		t.Fatalf("ParseBytes: %v", err)
+	}
+	if p.Suppressions == nil {
+		t.Fatal("Suppressions is nil")
+	}
+	rules, ok := p.Suppressions["deprecated-job"]
+	if !ok {
+		t.Fatal("no suppression for deprecated-job")
+	}
+	if len(rules) != 1 || rules[0] != "GL007" {
+		t.Errorf("rules = %v, want [GL007]", rules)
+	}
+	if _, ok := p.Suppressions["normal-job"]; ok {
+		t.Error("normal-job should have no suppressions")
+	}
+}

internal/model/pipeline.go

@@ -12,6 +12,10 @@ type Pipeline struct {
 	// Jobs holds every non-reserved top-level key (i.e. job definitions).
 	Jobs    map[string]Job            `yaml:"-"`
 	RawJobs map[string]map[string]any `yaml:"-"` // pre-resolution raw maps, used by the resolver
+	// Suppressions maps job names to lists of suppressed rule IDs parsed from
+	// "# glint: ignore RULE" comments in the pipeline YAML. Only populated for
+	// the root pipeline file (not for included templates).
+	Suppressions map[string][]string `yaml:"-"`
 }
 
 // SetJobOrigin sets the File field on all jobs that don't already have one.
@@ -84,6 +88,7 @@ type Rule struct {
 	When      string         `yaml:"when"`
 	Changes   any            `yaml:"changes"`   // []string or {paths,compare_to} map
 	Exists    any            `yaml:"exists"`    // []string or map form
+	Variables map[string]any `yaml:"variables"` // set/override variables when rule matches (GitLab CI 15.0+)
 }
 
 // ReservedKeys are top-level GitLab CI keys that are NOT job definitions.

internal/resolver/extends.go

@@ -80,6 +80,11 @@ func Resolve(p *model.Pipeline) ([]ExtendWarning, error) {
 			return extWarnings, fmt.Errorf("job %q: re-decoding merged definition: %w", name, err)
 		}
 		j.Name = name
+		// Preserve source location — File/Line are not part of the YAML map
+		// and are lost during the encode/decode round-trip.
+		orig := p.Jobs[name]
+		j.File = orig.File
+		j.Line = orig.Line
 		p.Jobs[name] = j
 	}
 

internal/resolver/includes.go

@@ -4,12 +4,27 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"regexp"
 	"strings"
 
 	"git.k3nny.fr/glint/internal/fetcher"
 	"git.k3nny.fr/glint/internal/model"
 )
 
+// maxIncludeDepth is the maximum nesting level for include: chains.
+// This matches GitLab's own documented limit and also guards against
+// include cycles that slip past the visited-key deduplication.
+const maxIncludeDepth = 100
+
+// inputPlaceholderRe matches GitLab CI component input references:
+//
+//	$[[ inputs.KEY ]]
+//	$[[ inputs.KEY | default('value') ]]
+//	$[[ inputs.KEY | default(true) ]]
+//	$[[ inputs.KEY | default(123) ]]
+var inputPlaceholderRe = regexp.MustCompile(
+	`\$\[\[\s*inputs\.(\w+)(?:\s*\|\s*default\(([^)]*)\))?\s*\]\]`)
+
 // IncludeWarning describes an include entry that could not be resolved.
 // These are surfaced to the user as [WARNING] lines before the lint findings.
 type IncludeWarning struct {
@@ -53,11 +68,18 @@ type ExtendWarning struct {
 // processing included files (forwarded from resolver.Resolve calls).
 func ResolveIncludes(p *model.Pipeline, cfg fetcher.GitLabConfig, rootDir string) ([]IncludeWarning, []ExtendWarning) {
 	visited := map[string]bool{}
-	return resolveIncludes(p, p.Include, cfg, rootDir, visited)
+	return resolveIncludes(p, p.Include, cfg, rootDir, visited, 0)
 }
 
 // resolveIncludes is the recursive core of ResolveIncludes.
-func resolveIncludes(p *model.Pipeline, includes []any, cfg fetcher.GitLabConfig, rootDir string, visited map[string]bool) ([]IncludeWarning, []ExtendWarning) {
+func resolveIncludes(p *model.Pipeline, includes []any, cfg fetcher.GitLabConfig, rootDir string, visited map[string]bool, depth int) ([]IncludeWarning, []ExtendWarning) {
+	if depth > maxIncludeDepth {
+		return []IncludeWarning{{
+			Label: "includes",
+			Err:   fmt.Errorf("include nesting depth exceeded (%d levels) — possible include cycle detected", maxIncludeDepth),
+		}}, nil
+	}
+
 	var warnings []IncludeWarning
 	var extWarnings []ExtendWarning
 
@@ -68,14 +90,15 @@ func resolveIncludes(p *model.Pipeline, includes []any, cfg fetcher.GitLabConfig
 		}
 
 		if project, _ := entry["project"].(string); project != "" {
-			w, ew := resolveProjectInclude(p, entry, project, cfg, rootDir, visited)
+			w, ew := resolveProjectInclude(p, entry, project, cfg, rootDir, visited, depth)
 			warnings = append(warnings, w...)
 			extWarnings = append(extWarnings, ew...)
 			continue
 		}
 
 		if compRef, _ := entry["component"].(string); compRef != "" {
-			w, ew, hadErr := resolveComponentInclude(p, compRef, cfg, rootDir, visited)
+			inputs := extractInputs(entry)
+			w, ew, hadErr := resolveComponentInclude(p, compRef, inputs, cfg, rootDir, visited, depth)
 			if hadErr {
 				warnings = append(warnings, w)
 			}
@@ -84,14 +107,14 @@ func resolveIncludes(p *model.Pipeline, includes []any, cfg fetcher.GitLabConfig
 		}
 
 		if local, _ := entry["local"].(string); local != "" {
-			w, ew := resolveLocalInclude(p, local, cfg, rootDir, visited)
+			w, ew := resolveLocalInclude(p, local, cfg, rootDir, visited, depth)
 			warnings = append(warnings, w...)
 			extWarnings = append(extWarnings, ew...)
 			continue
 		}
 
 		if remote, _ := entry["remote"].(string); remote != "" {
-			w, ew := resolveRemoteInclude(p, remote, cfg, rootDir, visited)
+			w, ew := resolveRemoteInclude(p, remote, cfg, rootDir, visited, depth)
 			warnings = append(warnings, w...)
 			extWarnings = append(extWarnings, ew...)
 			continue
@@ -105,7 +128,7 @@ func resolveIncludes(p *model.Pipeline, includes []any, cfg fetcher.GitLabConfig
 // resolveLocalInclude reads a local file from disk (paths are always relative
 // to the repository root, with or without a leading slash), recursively
 // resolves its own includes, and merges it into p.
-func resolveLocalInclude(p *model.Pipeline, rawPath string, cfg fetcher.GitLabConfig, rootDir string, visited map[string]bool) ([]IncludeWarning, []ExtendWarning) {
+func resolveLocalInclude(p *model.Pipeline, rawPath string, cfg fetcher.GitLabConfig, rootDir string, visited map[string]bool, depth int) ([]IncludeWarning, []ExtendWarning) {
 	relPath := strings.TrimPrefix(rawPath, "/")
 	absPath := filepath.Join(rootDir, relPath)
 	label := "local " + rawPath
@@ -131,7 +154,7 @@ func resolveLocalInclude(p *model.Pipeline, rawPath string, cfg fetcher.GitLabCo
 	var warnings []IncludeWarning
 	var extWarnings []ExtendWarning
 	if len(included.Include) > 0 {
-		w, ew := resolveIncludes(included, included.Include, cfg, rootDir, visited)
+		w, ew := resolveIncludes(included, included.Include, cfg, rootDir, visited, depth+1)
 		warnings = append(warnings, w...)
 		extWarnings = append(extWarnings, ew...)
 	}
@@ -142,7 +165,7 @@ func resolveLocalInclude(p *model.Pipeline, rawPath string, cfg fetcher.GitLabCo
 
 // resolveRemoteInclude fetches a plain HTTPS URL, parses it as CI YAML, and
 // merges it into p. Sub-includes of the fetched file are resolved recursively.
-func resolveRemoteInclude(p *model.Pipeline, rawURL string, cfg fetcher.GitLabConfig, rootDir string, visited map[string]bool) ([]IncludeWarning, []ExtendWarning) {
+func resolveRemoteInclude(p *model.Pipeline, rawURL string, cfg fetcher.GitLabConfig, rootDir string, visited map[string]bool, depth int) ([]IncludeWarning, []ExtendWarning) {
 	label := "remote " + rawURL
 
 	if visited[rawURL] {
@@ -150,7 +173,7 @@ func resolveRemoteInclude(p *model.Pipeline, rawURL string, cfg fetcher.GitLabCo
 	}
 	visited[rawURL] = true
 
-	data, err := fetcher.FetchURL(rawURL)
+	data, err := cfg.FetchURL(rawURL)
 	if err != nil {
 		return []IncludeWarning{{Label: label, Err: err}}, nil
 	}
@@ -164,7 +187,7 @@ func resolveRemoteInclude(p *model.Pipeline, rawURL string, cfg fetcher.GitLabCo
 	var warnings []IncludeWarning
 	var extWarnings []ExtendWarning
 	if len(included.Include) > 0 {
-		w, ew := resolveIncludes(included, included.Include, cfg, rootDir, visited)
+		w, ew := resolveIncludes(included, included.Include, cfg, rootDir, visited, depth+1)
 		warnings = append(warnings, w...)
 		extWarnings = append(extWarnings, ew...)
 	}
@@ -175,7 +198,7 @@ func resolveRemoteInclude(p *model.Pipeline, rawURL string, cfg fetcher.GitLabCo
 
 // resolveProjectInclude fetches all files listed under a single project: entry
 // and merges them into p.
-func resolveProjectInclude(p *model.Pipeline, entry map[string]any, project string, cfg fetcher.GitLabConfig, rootDir string, visited map[string]bool) ([]IncludeWarning, []ExtendWarning) {
+func resolveProjectInclude(p *model.Pipeline, entry map[string]any, project string, cfg fetcher.GitLabConfig, rootDir string, visited map[string]bool, depth int) ([]IncludeWarning, []ExtendWarning) {
 	ref, _ := entry["ref"].(string)
 	var warnings []IncludeWarning
 	var extWarnings []ExtendWarning
@@ -186,6 +209,12 @@ func resolveProjectInclude(p *model.Pipeline, entry map[string]any, project stri
 			label += "@" + ref
 		}
 
+		visitKey := fmt.Sprintf("project:%s:%s@%s", project, filePath, ref)
+		if visited[visitKey] {
+			continue
+		}
+		visited[visitKey] = true
+
 		if !cfg.HasToken() {
 			warnings = append(warnings, IncludeWarning{Label: label, Skipped: true})
 			continue
@@ -205,7 +234,7 @@ func resolveProjectInclude(p *model.Pipeline, entry map[string]any, project stri
 		included.SetJobOrigin(label)
 
 		if len(included.Include) > 0 {
-			w, ew := resolveIncludes(included, included.Include, cfg, rootDir, visited)
+			w, ew := resolveIncludes(included, included.Include, cfg, rootDir, visited, depth+1)
 			warnings = append(warnings, w...)
 			extWarnings = append(extWarnings, ew...)
 		}
@@ -215,9 +244,11 @@ func resolveProjectInclude(p *model.Pipeline, entry map[string]any, project stri
 	return warnings, extWarnings
 }
 
-// resolveComponentInclude fetches a CI/CD catalog component and merges it into p.
+// resolveComponentInclude fetches a CI/CD catalog component, substitutes any
+// $[[ inputs.KEY ]] placeholders with values from `inputs` (the include's
+// with: block), and merges the result into p.
 // Returns (warning, extWarnings, true) if something went wrong; (zero, nil, false) on success.
-func resolveComponentInclude(p *model.Pipeline, ref string, cfg fetcher.GitLabConfig, rootDir string, visited map[string]bool) (IncludeWarning, []ExtendWarning, bool) {
+func resolveComponentInclude(p *model.Pipeline, ref string, inputs map[string]any, cfg fetcher.GitLabConfig, rootDir string, visited map[string]bool, depth int) (IncludeWarning, []ExtendWarning, bool) {
 	label := "component " + ref
 
 	if strings.ContainsRune(ref, '$') {
@@ -227,6 +258,12 @@ func resolveComponentInclude(p *model.Pipeline, ref string, cfg fetcher.GitLabCo
 		}, nil, true
 	}
 
+	visitKey := "component:" + ref
+	if visited[visitKey] {
+		return IncludeWarning{}, nil, false
+	}
+	visited[visitKey] = true
+
 	host, project, component, version, err := parseComponentRef(ref)
 	if err != nil {
 		return IncludeWarning{Label: label, Err: err}, nil, true
@@ -238,6 +275,9 @@ func resolveComponentInclude(p *model.Pipeline, ref string, cfg fetcher.GitLabCo
 		return IncludeWarning{Label: label, Err: err}, nil, true
 	}
 
+	// Substitute $[[ inputs.KEY ]] placeholders with the values from with:.
+	data = substituteInputs(data, inputs)
+
 	included, err := model.ParseBytes(data)
 	if err != nil {
 		return IncludeWarning{Label: label, Err: fmt.Errorf("parsing component YAML: %w", err)}, nil, true
@@ -246,7 +286,7 @@ func resolveComponentInclude(p *model.Pipeline, ref string, cfg fetcher.GitLabCo
 
 	var extWarnings []ExtendWarning
 	if len(included.Include) > 0 {
-		_, ew := resolveIncludes(included, included.Include, cfg, rootDir, visited)
+		_, ew := resolveIncludes(included, included.Include, cfg, rootDir, visited, depth+1)
 		extWarnings = append(extWarnings, ew...)
 	}
 
@@ -254,6 +294,45 @@ func resolveComponentInclude(p *model.Pipeline, ref string, cfg fetcher.GitLabCo
 	return IncludeWarning{}, extWarnings, false
 }
 
+// substituteInputs replaces all $[[ inputs.KEY ]] and
+// $[[ inputs.KEY | default('…') ]] placeholders in data with the corresponding
+// values from inputs (the with: block of the component include entry).
+// Missing keys with no default become empty strings.
+// Missing keys with a default use the default value (single/double quotes stripped).
+func substituteInputs(data []byte, inputs map[string]any) []byte {
+	if len(data) == 0 {
+		return data
+	}
+	return inputPlaceholderRe.ReplaceAllFunc(data, func(match []byte) []byte {
+		groups := inputPlaceholderRe.FindSubmatch(match)
+		if len(groups) < 2 {
+			return match
+		}
+		if val, ok := inputs[string(groups[1])]; ok {
+			return []byte(fmt.Sprintf("%v", val))
+		}
+		// Use the default value when the key is absent from inputs.
+		if len(groups) >= 3 && len(groups[2]) > 0 {
+			def := strings.TrimSpace(string(groups[2]))
+			if (strings.HasPrefix(def, "'") && strings.HasSuffix(def, "'")) ||
+				(strings.HasPrefix(def, `"`) && strings.HasSuffix(def, `"`)) {
+				def = def[1 : len(def)-1]
+			}
+			return []byte(def)
+		}
+		return []byte("")
+	})
+}
+
+// extractInputs returns the with: map from a component include entry, or nil.
+func extractInputs(entry map[string]any) map[string]any {
+	with, ok := entry["with"].(map[string]any)
+	if !ok {
+		return nil
+	}
+	return with
+}
+
 // parseComponentRef parses a CI/CD component reference of the form:
 //
 //	<host>/<project-path>/<component-name>@<version>
@@ -326,8 +405,9 @@ func includeFiles(entry map[string]any) []string {
 	return nil
 }
 
-// mergeIncluded copies jobs and stages from src into dst.
-// dst (the main pipeline) always wins when a key already exists.
+// mergeIncluded copies jobs, stages, and variables from src into dst.
+// dst (the main pipeline) always wins when a key already exists — this matches
+// GitLab's precedence rule where root-pipeline values override included templates.
 func mergeIncluded(dst, src *model.Pipeline) {
 	stageSet := make(map[string]bool, len(dst.Stages))
 	for _, s := range dst.Stages {
@@ -348,4 +428,16 @@ func mergeIncluded(dst, src *model.Pipeline) {
 			}
 		}
 	}
+
+	// Merge pipeline-level variables: dst wins on conflict (root overrides includes).
+	if len(src.Variables) > 0 {
+		if dst.Variables == nil {
+			dst.Variables = make(map[string]any, len(src.Variables))
+		}
+		for k, v := range src.Variables {
+			if _, exists := dst.Variables[k]; !exists {
+				dst.Variables[k] = v
+			}
+		}
+	}
 }

internal/resolver/includes_test.go

@@ -0,0 +1,90 @@
+package resolver
+
+import (
+	"testing"
+)
+
+func TestSubstituteInputs(t *testing.T) {
+	cases := []struct {
+		name   string
+		data   string
+		inputs map[string]any
+		want   string
+	}{
+		{
+			name:   "simple substitution",
+			data:   `stage: $[[ inputs.STAGE ]]`,
+			inputs: map[string]any{"STAGE": "deploy"},
+			want:   `stage: deploy`,
+		},
+		{
+			name:   "default string used when key absent",
+			data:   `image: $[[ inputs.IMAGE | default('ubuntu:22.04') ]]`,
+			inputs: map[string]any{},
+			want:   `image: ubuntu:22.04`,
+		},
+		{
+			name:   "input overrides default",
+			data:   `image: $[[ inputs.IMAGE | default('ubuntu:22.04') ]]`,
+			inputs: map[string]any{"IMAGE": "alpine:3.18"},
+			want:   `image: alpine:3.18`,
+		},
+		{
+			name:   "integer input",
+			data:   `variables:\n  RETRIES: $[[ inputs.RETRY_COUNT ]]`,
+			inputs: map[string]any{"RETRY_COUNT": 3},
+			want:   `variables:\n  RETRIES: 3`,
+		},
+		{
+			name:   "boolean default",
+			data:   `variables:\n  ENABLED: $[[ inputs.ENABLE | default(true) ]]`,
+			inputs: map[string]any{},
+			want:   `variables:\n  ENABLED: true`,
+		},
+		{
+			name:   "numeric default",
+			data:   `variables:\n  COUNT: $[[ inputs.COUNT | default(5) ]]`,
+			inputs: map[string]any{},
+			want:   `variables:\n  COUNT: 5`,
+		},
+		{
+			name:   "missing key no default becomes empty",
+			data:   `script: $[[ inputs.CMD ]]`,
+			inputs: map[string]any{},
+			want:   `script: `,
+		},
+		{
+			name:   "no placeholders unchanged",
+			data:   `stage: build`,
+			inputs: nil,
+			want:   `stage: build`,
+		},
+		{
+			name:   "multiple placeholders in one document",
+			data:   "stage: $[[ inputs.STAGE ]]\nimage: $[[ inputs.IMAGE | default('alpine') ]]",
+			inputs: map[string]any{"STAGE": "test"},
+			want:   "stage: test\nimage: alpine",
+		},
+		{
+			name:   "double-quoted default",
+			data:   `image: $[[ inputs.IMAGE | default("debian:12") ]]`,
+			inputs: map[string]any{},
+			want:   `image: debian:12`,
+		},
+		{
+			name:   "whitespace inside brackets",
+			data:   `stage: $[[ inputs.STAGE  ]]`,
+			inputs: map[string]any{"STAGE": "build"},
+			want:   `stage: build`,
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.name, func(t *testing.T) {
+			got := string(substituteInputs([]byte(tc.data), tc.inputs))
+			if got != tc.want {
+				t.Errorf("substituteInputs:\n got  %q\n want %q", got, tc.want)
+			}
+		})
+	}
+}

testdata/config_ignored/.gitlab-ci.yml

@@ -0,0 +1,10 @@
+stages:
+  - build
+
+# GL007 (only/except deprecated) would normally fire here, but the .glint.yml
+# in this directory ignores GL007.
+deprecated-job:
+  stage: build
+  only:
+    - main
+  script: echo ok

testdata/config_ignored/.glint.yml

@@ -0,0 +1,2 @@
+ignore:
+  - GL007

testdata/config_severity/.gitlab-ci.yml

@@ -0,0 +1,8 @@
+stages:
+  - build
+
+# GL004 (undefined stage) is demoted to warning by .glint.yml, so the exit
+# code must be 0 even though there is a finding.
+bad-stage-job:
+  stage: nonexistent
+  script: echo hi

testdata/config_severity/.glint.yml

@@ -0,0 +1,2 @@
+severity:
+  GL004: warning

testdata/config_suppress/.gitlab-ci.yml

@@ -0,0 +1,15 @@
+stages:
+  - build
+
+# glint: ignore GL007
+suppressed-job:
+  stage: build
+  only:
+    - main
+  script: echo ok
+
+still-flagged-job:
+  stage: build
+  only:
+    - main
+  script: echo ok

testdata/dead_rules.yml

@@ -0,0 +1,59 @@
+---
+# dead_rules.yml
+# Exercises GL033: rules: block where every rule has when: never.
+# All flagged jobs produce a WARNING (exit 0). Valid jobs must not be flagged.
+
+stages:
+  - build
+  - test
+  - deploy
+
+# ── Jobs that should trigger GL033 ─────────────────────────────────────────
+
+# Single bare catch-all never — job is always excluded.
+disabled-job:
+  stage: build
+  script: echo disabled
+  rules:
+    - when: never
+
+# Multiple rules, all when: never — no branch can activate this job.
+dead-multi:
+  stage: test
+  script: echo dead
+  rules:
+    - if: '$CI_COMMIT_BRANCH == "main"'
+      when: never
+    - if: '$CI_COMMIT_BRANCH == "develop"'
+      when: never
+    - when: never
+
+# ── Jobs that must NOT trigger GL033 ───────────────────────────────────────
+
+# First rule can activate.
+main-only:
+  stage: build
+  script: echo main
+  rules:
+    - if: '$CI_COMMIT_BRANCH == "main"'
+      when: on_success
+    - when: never
+
+# Rule with no when: — defaults to on_success, so job is reachable.
+implicit-on-success:
+  stage: test
+  script: echo implicit
+  rules:
+    - if: '$CI_COMMIT_BRANCH == "develop"'
+
+# Manual is not never — job is reachable (just gated).
+manual-gate:
+  stage: deploy
+  script: echo deploy
+  rules:
+    - when: manual
+
+# No rules at all — always active.
+always-active:
+  stage: build
+  script: echo always

testdata/inherit_dead.yml

@@ -0,0 +1,26 @@
+stages:
+  - build
+  - test
+
+# No default: block — any inherit: default: declaration is a no-op.
+
+# GL043: inherit: default: false but no default: block.
+isolated-job:
+  stage: build
+  inherit:
+    default: false
+  script: echo isolated
+
+# GL043: inherit: default: [list] but no default: block.
+selective-inherit-job:
+  stage: test
+  inherit:
+    default: [image, tags]
+  script: echo selective
+
+# Not GL043: inherit only touches variables: (no default: check needed).
+vars-inherit-job:
+  stage: test
+  inherit:
+    variables: false
+  script: echo vars-only

testdata/inherit_dead_fields.yml

@@ -0,0 +1,20 @@
+stages:
+  - build
+  - test
+
+default:
+  image: node:20
+
+# GL043: before_script is in the list but not defined in default:.
+selective-bad:
+  stage: build
+  inherit:
+    default: [image, before_script]   # before_script not in default:
+  script: echo hi
+
+# Not GL043: image IS defined in default: — list is valid.
+selective-good:
+  stage: test
+  inherit:
+    default: [image]
+  script: echo hi

testdata/keywords_valid.yml

@@ -9,6 +9,10 @@ workflow:
       when: always
     - when: never
 
+default:
+  tags:
+    - docker
+
 variables:
   GO_VERSION: "1.26"
 

testdata/new_rules_invalid.yml

@@ -0,0 +1,81 @@
+stages:
+  - build
+  - test
+  - test
+
+variables:
+  DEPLOY_ENV: staging
+
+# GL040: duplicate stage "test" above triggers a warning
+
+# GL034: services map form missing name
+service-no-name:
+  stage: build
+  script: [echo ok]
+  services:
+    - alias: my-svc
+
+# GL034: services map form with invalid alias (contains spaces)
+service-bad-alias:
+  stage: build
+  script: [echo ok]
+  services:
+    - name: redis:latest
+      alias: "my bad alias"
+
+# GL035: rules:changes with absolute path
+absolute-changes:
+  stage: test
+  script: [echo test]
+  rules:
+    - changes:
+        - /src/main.go
+
+# GL035: rules:exists with absolute path
+absolute-exists:
+  stage: test
+  script: [echo test]
+  rules:
+    - exists:
+        - /Dockerfile
+
+# GL036: invalid timeout format
+bad-timeout:
+  stage: build
+  script: [echo build]
+  timeout: forever
+
+# GL037: id_tokens entry missing aud
+bad-token:
+  stage: test
+  script: [echo test]
+  id_tokens:
+    MY_TOKEN:
+      expire: 3600
+
+# GL038: secrets entry missing provider
+bad-secret:
+  stage: test
+  script: [echo test]
+  secrets:
+    DB_PASSWORD:
+      expire: 3600
+
+# GL039: pages keyword but publish dir not in artifacts.paths
+bad-pages:
+  stage: build
+  script: [mkdocs build]
+  pages:
+    publish: dist
+  artifacts:
+    paths:
+      - public
+
+# GL041: cache.key.files contains a glob
+bad-cache-glob:
+  stage: build
+  script: [echo build]
+  cache:
+    key:
+      files:
+        - "*.sum"

testdata/new_rules_valid.yml

@@ -0,0 +1,116 @@
+stages:
+  - build
+  - test
+  - deploy
+
+variables:
+  DEPLOY_ENV: staging
+
+# GL034: services — string form and map form with name are both valid
+service-string:
+  stage: build
+  script: [echo ok]
+  services:
+    - redis:latest
+    - postgres:14
+
+service-map:
+  stage: build
+  script: [echo ok]
+  services:
+    - name: postgres:14
+      alias: db
+    - name: redis:latest
+      alias: cache-svc
+
+# GL035: rules:changes/exists — relative paths are valid
+rules-relative:
+  stage: test
+  script: [echo test]
+  rules:
+    - if: '$CI_COMMIT_BRANCH == "main"'
+      changes:
+        - src/**/*.go
+        - tests/*.go
+    - exists:
+        - Dockerfile
+        - docker-compose.yml
+      when: on_success
+
+# GL036: timeout — valid duration strings
+timeout-short:
+  stage: build
+  script: [echo build]
+  timeout: 30m
+
+timeout-long:
+  stage: build
+  script: [echo build]
+  timeout: 1h 30m
+
+timeout-words:
+  stage: test
+  script: [echo test]
+  timeout: 90 minutes
+
+timeout-combined:
+  stage: deploy
+  script: [echo deploy]
+  timeout: 2 hours 30 minutes
+
+# GL037: id_tokens — entry with valid aud
+token-job:
+  stage: build
+  script: [echo build]
+  id_tokens:
+    VAULT_TOKEN:
+      aud: https://vault.example.com
+    SIGSTORE_TOKEN:
+      aud: sigstore
+
+# GL038: secrets — valid provider keys
+secret-vault:
+  stage: deploy
+  script: [echo deploy]
+  secrets:
+    DB_PASSWORD:
+      vault: production/db/password@ops
+
+secret-gcp:
+  stage: deploy
+  script: [echo deploy]
+  secrets:
+    API_KEY:
+      gcp_secret_manager:
+        name: my-api-key
+        version: latest
+
+# GL039: pages keyword — publish dir present in artifacts.paths
+pages-keyword:
+  stage: deploy
+  script: [mkdocs build]
+  pages:
+    publish: site
+  artifacts:
+    paths:
+      - site
+
+pages-keyword-default:
+  stage: deploy
+  script: [make docs]
+  pages: true
+  artifacts:
+    paths:
+      - public
+
+# GL040: no duplicate stages (unique stages defined above)
+
+# GL041: cache.key.files — list of exact paths
+cache-key-job:
+  stage: build
+  script: [echo build]
+  cache:
+    key:
+      files:
+        - go.sum
+        - go.mod

testdata/rules_if_expr.yml

@@ -0,0 +1,51 @@
+---
+# rules_if_expr.yml
+# Exercises the rules:if: expression evaluator for:
+#   - Multi-line block-scalar expressions (|| on next line)
+#   - ${VAR} curly-brace variable syntax
+#   - Regex flags (/pattern/i case-insensitive)
+#   - Parenthesised compound expressions
+# Expected: exits 0 (lints clean with no context).
+
+stages:
+  - build
+  - deploy
+
+variables:
+  DEPLOY_ENVIRONMENTS:
+    value: "staging"
+    description: "Target deployment environment"
+
+build:
+  stage: build
+  script: make build
+  rules:
+    # Multi-line expression: || on next line
+    - if: |
+        $CI_COMMIT_BRANCH == "main" ||
+        $CI_COMMIT_BRANCH == "develop"
+      when: on_success
+    - when: never
+
+deploy-feature:
+  stage: deploy
+  script: make deploy
+  rules:
+    # ${VAR} curly-brace syntax
+    - if: '${CI_COMMIT_BRANCH} != null && ${CI_COMMIT_TAG} == null'
+      when: manual
+    - when: never
+
+release:
+  stage: deploy
+  script: make release
+  rules:
+    # Case-insensitive regex flag
+    - if: '$CI_COMMIT_BRANCH =~ /^(main|master)$/i'
+      when: on_success
+    # Parenthesised compound with multi-line
+    - if: >-
+        ($CI_COMMIT_TAG != null) &&
+        ($CI_PIPELINE_SOURCE == "push" || $CI_PIPELINE_SOURCE == "web")
+      when: on_success
+    - when: never

testdata/static_dead_rules.yml

@@ -0,0 +1,48 @@
+stages:
+  - deploy
+  - test
+
+variables:
+  DEPLOY: "false"
+  SKIP_TEST: "true"
+
+# GL042: both if: conditions always evaluate to false given the declared variables.
+always-dead-deploy:
+  stage: deploy
+  rules:
+    - if: '$DEPLOY == "true"'
+      when: on_success
+  script: echo deploy
+
+# GL042: if: is false, explicit when:on_success rule — still never fires.
+always-dead-test:
+  stage: test
+  rules:
+    - if: '$SKIP_TEST == "false"'
+      when: on_success
+  script: echo test
+
+# Not GL042: references a predefined CI_ variable → unknown value → skip check.
+predefined-var-job:
+  stage: test
+  rules:
+    - if: '$CI_COMMIT_BRANCH == "nonexistent-branch"'
+      when: on_success
+  script: echo branch
+
+# Not GL042: has an unconditional rule (no if: → always matches).
+unconditional-job:
+  stage: test
+  rules:
+    - if: '$DEPLOY == "true"'
+      when: never
+    - when: on_success
+  script: echo always
+
+# Not GL042: references undeclared variable → unknown → conservative.
+undeclared-var-job:
+  stage: test
+  rules:
+    - if: '$UNDECLARED_VAR == "something"'
+      when: on_success
+  script: echo undeclared

testdata/variable_refs.yml

@@ -0,0 +1,51 @@
+---
+# variable_refs.yml
+# Verifies that GL032 does not fire for variables that are declared or predefined.
+# Covers: pipeline variables:, job variables:, workflow:rules:variables:, and CI_* prefixes.
+# Expected: exits 0 (no errors; no GL032 warnings).
+
+stages:
+  - build
+  - deploy
+
+variables:
+  DEPLOY_TARGET: "staging"
+  FEATURE_FLAG: "false"
+
+workflow:
+  rules:
+    - if: '$CI_COMMIT_BRANCH == "main"'
+      variables:
+        DEPLOY_TARGET: "production"
+    - when: always
+
+build:
+  stage: build
+  script: make build
+  rules:
+    # pipeline-level variable — GL032 must not fire
+    - if: '$DEPLOY_TARGET == "staging"'
+      when: on_success
+    # predefined CI variable — GL032 must not fire
+    - if: '$CI_COMMIT_BRANCH =~ /^feat\/.+/'
+      when: manual
+
+deploy:
+  stage: deploy
+  script: make deploy
+  variables:
+    DEPLOY_REGION: "us-east-1"
+  rules:
+    # pipeline-level variable — no warning
+    - if: '$FEATURE_FLAG == "true"'
+      when: never
+    # workflow-rule-injected variable — no warning
+    - if: '$DEPLOY_TARGET == "production"'
+      when: on_success
+    # job-level variable — no warning
+    - if: '$DEPLOY_REGION == "us-east-1"'
+      when: on_success
+    # predefined GITLAB_ variable — no warning
+    - if: '$GITLAB_USER_LOGIN == "bot"'
+      when: never
+    - when: manual

testdata/variable_refs_included.yml

@@ -0,0 +1,25 @@
+---
+# variable_refs_included.yml
+# GL032 must NOT fire for variables declared in an included file.
+# The included file (variable_refs_included_template.yml) declares TEMPLATE_VAR.
+# Expected: exits 0 (no errors; no GL032 warnings).
+
+stages:
+  - build
+
+include:
+  - local: /variable_refs_included_template.yml
+
+build:
+  stage: build
+  script: make build
+  rules:
+    # TEMPLATE_VAR comes from the included file — GL032 must not fire.
+    - if: '$TEMPLATE_VAR == "enabled"'
+      when: on_success
+    # ROOT_VAR is declared in this file — GL032 must not fire.
+    - if: '$ROOT_VAR == "yes"'
+      when: manual
+
+variables:
+  ROOT_VAR: "yes"

testdata/variable_refs_included_template.yml

@@ -0,0 +1,6 @@
+---
+# Included by variable_refs_included.yml — declares a pipeline-level variable
+# that the parent pipeline's jobs reference in rules:if: expressions.
+
+variables:
+  TEMPLATE_VAR: "enabled"

testdata/workflow_escape.yml

@@ -0,0 +1,57 @@
+---
+# workflow_vars.yml
+# Exercises workflow:rules:variables: injection.
+# The matching workflow rule sets DEPLOY_TARGET; job rules use it.
+#
+# Expected behaviour per context:
+#   (no context)       → all jobs active (no context evaluation)
+#   --branch main      → deploy-prod active, deploy-staging skipped
+#   --branch develop   → deploy-prod skipped, deploy-staging active
+#   --branch feat/x    → deploy-prod skipped, deploy-staging skipped (manual)
+
+stages:
+  - build
+  - deploy
+
+variables:
+  DEPLOY_TARGET:
+    value: ""
+    description: "Deployment target — set by workflow rules"
+
+workflow:
+  rules:
+    - if: "
+        $WORKFLOW = 'gitflow' &&
+        $CI_PIPELINE_SOURCE == /(push|web)/ && 
+        $CI_COMMIT_BRANCH =~ /^us\//
+        "
+      variables:
+        DEPLOY_TARGET: production
+        BUILD: true
+        TEST: true        
+    - if: '$CI_COMMIT_BRANCH == "develop"'
+      variables:
+        DEPLOY_TARGET: staging
+    - when: always
+
+build:
+  stage: build
+  script: make build
+  rules:
+    - when: always
+
+deploy-prod:
+  stage: deploy
+  script: make deploy ENV=production
+  rules:
+    - if: '$DEPLOY_TARGET == "production"'
+      when: on_success
+    - when: never
+
+deploy-staging:
+  stage: deploy
+  script: make deploy ENV=staging
+  rules:
+    - if: '$DEPLOY_TARGET == "staging"'
+      when: on_success
+    - when: never

testdata/workflow_vars.yml

@@ -0,0 +1,57 @@
+---
+# workflow_vars.yml
+# Exercises workflow:rules:variables: injection.
+# The matching workflow rule sets DEPLOY_TARGET; job rules use it.
+#
+# Expected behaviour per context:
+#   --branch main             → only build active (no workflow rule matches; WORKFLOW var not set)
+#   --branch develop          → deploy-staging active, deploy-prod skipped
+#   --branch feat/x           → only build active (when: always fallback, no deploy vars)
+#   --var WORKFLOW=gitflow --branch us/feature → deploy-prod + build active
+
+stages:
+  - build
+  - deploy
+
+variables:
+  DEPLOY_TARGET:
+    value: ""
+    description: "Deployment target — set by workflow rules"
+
+workflow:
+  rules:
+    - if: "
+        $WORKFLOW = 'gitflow' &&
+        $CI_PIPELINE_SOURCE == /(push|web)/ && 
+        $CI_COMMIT_BRANCH =~ /^us\//
+        "
+      variables:
+        DEPLOY_TARGET: production
+        DEPLOY: true
+        BUILD: true
+    - if: '$CI_COMMIT_BRANCH == "develop"'
+      variables:
+        DEPLOY_TARGET: staging
+    - when: always
+
+build:
+  stage: build
+  script: make build
+  rules:
+    - when: always
+
+deploy-prod:
+  stage: deploy
+  script: make deploy ENV=production
+  rules:
+    - if: '$DEPLOY_TARGET == "production" && $DEPLOY == "true"'
+      when: on_success
+    - when: never
+
+deploy-staging:
+  stage: deploy
+  script: make deploy ENV=staging
+  rules:
+    - if: '$DEPLOY_TARGET == "staging" '
+      when: on_success
+    - when: never