feat(lsp): add Language Server Protocol server (glint lsp)

New internal/lsp package implements a minimal JSON-RPC 2.0 LSP server
over stdin/stdout with Content-Length framing. Supported lifecycle:
initialize → initialized → shutdown → exit. Document sync: Full (sends
complete text on every change). Handles textDocument/didOpen,
didChange, didSave, didClose; publishes textDocument/publishDiagnostics
after every change. Rule IDs surface as the diagnostic `code` field
with `"glint"` as source. Parse errors produce an Error diagnostic at
the top of the document. Include resolution is best-effort (GITLAB_TOKEN
env var; ~/.cache/glint default cache). CLI: glint lsp [--token]
[--gitlab-url] [--cache-dir] [--offline].

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

.glint.yml.example

@@ -0,0 +1,66 @@
+# .glint.yml — glint project configuration
+#
+# Place this file anywhere between your .gitlab-ci.yml and the repository root.
+# glint searches upward from the pipeline file and stops at the first .git
+# boundary, so the repo root is the typical location.
+#
+# All keys are optional. Omit or comment out anything you don't need.
+
+# ── Rule suppression ──────────────────────────────────────────────────────────
+#
+# Suppress rules globally for this project. Suppressed rules produce no output
+# and do not affect the exit code.
+#
+ignore:
+  - GL007   # only:/except: used (migrating from legacy syntax)
+  - GL032   # rules:if: references undeclared variable (injected at runtime)
+
+# ── Severity overrides ────────────────────────────────────────────────────────
+#
+# Override the default severity of any rule.
+# Valid values: error | warning | ignore
+# "ignore" is equivalent to listing the rule in `ignore:` above.
+#
+severity:
+  GL004: warning   # demote "unknown stage" to warning during a stage migration
+  GL035: error     # promote absolute-path warning to a hard error
+  GL007: ignore    # equivalent to adding GL007 to ignore:
+
+# ── Extra stage names ─────────────────────────────────────────────────────────
+#
+# Declare stage names that are valid for this project beyond what is listed in
+# the pipeline's own `stages:` block. Jobs referencing these stages will not
+# be flagged by GL004. Useful when stages are defined in a shared parent
+# template that glint cannot reach.
+#
+stages:
+  - quality
+  - security
+  - compliance
+
+# ── GitLab token ──────────────────────────────────────────────────────────────
+#
+# Default personal access token (read_api scope) used to fetch `include:
+# project:` templates. This is the lowest-priority token source; it is
+# overridden by the --token flag and the GITLAB_TOKEN / CI_JOB_TOKEN /
+# GITLAB_PRIVATE_TOKEN environment variables.
+#
+# Avoid committing real tokens — use environment variables instead.
+#
+# token: glpat-xxxxxxxxxxxxxxxxxxxx
+
+# ── GitLab instance URL ───────────────────────────────────────────────────────
+#
+# Default GitLab instance URL, used when fetching project: and component:
+# includes. Overridden by --gitlab-url, CI_SERVER_URL, and GITLAB_URL.
+#
+# url: https://gitlab.example.com
+
+# ── Include cache directory ───────────────────────────────────────────────────
+#
+# Default directory for caching fetched remote includes (project: and
+# component:). The directory is created on first use. Overridden by
+# --cache-dir. When --offline is given without --cache-dir, glint defaults
+# to ~/.cache/glint regardless of this setting.
+#
+# cache_dir: ~/.cache/glint

.pre-commit-hooks.yaml

@@ -0,0 +1,11 @@
+- id: glint
+  name: glint — validate GitLab CI pipeline
+  description: >-
+    Lint .gitlab-ci.yml with glint before committing. Catches misconfigured
+    stages, invalid keywords, broken needs: graphs, deprecated patterns, and
+    more — without a GitLab server.
+  entry: glint check
+  language: golang
+  files: '(^|/)\.gitlab-ci\.yml$'
+  pass_filenames: true
+  minimum_pre_commit_version: '3.0.0'

CHANGELOG.md

@@ -5,6 +5,30 @@ 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).
 
+## [0.2.29] - 2026-06-26
+
+### Added
+
+- **LSP server** (`glint lsp`) — new `internal/lsp` package and `glint lsp` subcommand that starts a Language Server Protocol server over stdin/stdout using Content-Length–framed JSON-RPC 2.0. Editors (VS Code, Neovim, Emacs, JetBrains, etc.) can connect with any generic LSP client configuration. Supported methods: `initialize`, `initialized`, `shutdown`, `exit`, `textDocument/didOpen`, `textDocument/didChange`, `textDocument/didSave`, `textDocument/didClose`. On every document open or change the server runs the full glint lint pipeline and publishes diagnostics via `textDocument/publishDiagnostics`; each diagnostic carries the rule ID as its `code` field and `"glint"` as `source`. Parse errors are surfaced as an Error diagnostic at the top of the document. Include resolution is best-effort (uses `GITLAB_TOKEN` / `GITLAB_URL` env vars; default cache dir `~/.cache/glint`). CLI flags: `--token`, `--gitlab-url`, `--cache-dir`, `--offline`.
+
+## [0.2.28] - 2026-06-26
+
+### Added
+
+- **Pre-commit hook** — `.pre-commit-hooks.yaml` defines a `glint` hook with `language: golang`; pre-commit builds glint from source automatically on first run and re-runs `glint check` on any staged `.gitlab-ci.yml` changes. Reference: `repo: https://git.k3nny.fr/k3nny/glint, rev: v0.2.28`.
+
+- **GitLab CI component** (`templates/check.yml`) — a GitLab CI/CD Catalog–compatible component that downloads the glint Linux binary and runs `glint check` as a pipeline job. Accepts inputs: `stage` (default `validate`), `pipeline_file` (default `.gitlab-ci.yml`), `version` (default `latest`), `allow_failure` (default `false`), and `extra_args`. Can also be used as a plain local or remote include without the Catalog.
+
+- **GitHub Actions composite action** (`action.yml`) — downloads the glint Linux binary into `$RUNNER_TEMP`, adds it to `$GITHUB_PATH`, and runs `glint check`. Inputs: `version`, `file`, `args`. Mirror this repository to GitHub as `k3nny/glint` to reference it as `uses: k3nny/glint@v0.2.28`.
+
+## [0.2.27] - 2026-06-25
+
+### Added
+
+- **Fuzz testing** — `FuzzParseBytes` and `FuzzSanitizeYAMLEscapes` in `internal/model/fuzz_test.go` verify that neither the YAML parser nor the escape sanitizer panics on arbitrary input. Successful parses are also checked for structural integrity (non-nil pipeline, no empty job names). Run with `task fuzz` (default 30 s per target; set `FUZZ_TIME=60s` to extend). Found failures are saved to `testdata/fuzz/` for regression.
+
+- **Changelog automation** — `cliff.toml` configures [git-cliff](https://git-cliff.org) to generate Keep-a-Changelog–compatible release notes from Conventional Commits. `task changelog` regenerates `CHANGELOG.md` from the full git history; `task changelog-next` previews only unreleased commits without writing. Install git-cliff with `brew install git-cliff` or `cargo install git-cliff`.
+
 ## [0.2.26] - 2026-06-25
 
 ### Changed

README.md

@@ -6,7 +6,7 @@
 
 <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-v0.2.26-blue.svg" alt="Release"></a>
+  <a href="CHANGELOG.md"><img src="https://img.shields.io/badge/release-v0.2.29-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.
@@ -21,6 +21,7 @@ A local tool to validate and lint `.gitlab-ci.yml` pipelines without needing a G
 - **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; `--format mermaid` emits a Mermaid flowchart; `--format html` produces a self-contained HTML file with pan/zoom and a job-detail sidebar; context flags grey out skipped jobs
+- **LSP server** — `glint lsp` starts a Language Server Protocol server over stdin/stdout; connect with any LSP client to get inline diagnostics (rule ID as code, error/warning severity) in VS Code, Neovim, Emacs, JetBrains, etc.
 
 See [FEATURES.md](FEATURES.md) for the complete feature reference and lint rules table, and [ROADMAP.md](ROADMAP.md) for planned improvements.
 
@@ -32,7 +33,7 @@ See [FEATURES.md](FEATURES.md) for the complete feature reference and lint rules
 ## Installation
 
 ```bash
-git clone https://git.k3nny.fr/glint
+git clone https://git.k3nny.fr/k3nny/glint
 cd glint
 go build -o glint ./cmd/glint/...
 ```
@@ -52,12 +53,61 @@ 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
+  lsp      Start a Language Server Protocol server (stdin/stdout)
 ```
 
 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.
 
+## Integrations
+
+### Pre-commit hook
+
+Add to `.pre-commit-config.yaml` in your repository to run glint automatically whenever `.gitlab-ci.yml` changes:
+
+```yaml
+repos:
+  - repo: https://git.k3nny.fr/k3nny/glint
+    rev: v0.2.28
+    hooks:
+      - id: glint
+```
+
+Requires [pre-commit](https://pre-commit.com) and Go 1.21+. On first run, pre-commit builds glint from source automatically.
+
+### GitLab CI component
+
+Copy [`templates/check.yml`](templates/check.yml) into your repository and include it as a local file, or publish this repository to a GitLab CI/CD Catalog and reference it as a component:
+
+```yaml
+# As a local include (copy templates/check.yml to your repo first):
+include:
+  - local: .gitlab/glint-check.yml
+
+# As a Catalog component (after publishing to a GitLab instance):
+include:
+  - component: $CI_SERVER_FQDN/k3nny/glint/check@v0.2.28
+    inputs:
+      stage: validate          # optional, default: validate
+      allow_failure: true      # optional, default: false
+```
+
+The component downloads the glint Linux binary, runs `glint check`, and respects all inputs defined in the `spec:` block.
+
+### GitHub Actions
+
+Copy [`action.yml`](action.yml) from this repository, or mirror this repo to GitHub as `k3nny/glint` and reference it directly:
+
+```yaml
+- uses: k3nny/glint@v0.2.28
+  with:
+    file: .gitlab-ci.yml   # optional, default: .gitlab-ci.yml
+    args: '--format sarif' # optional
+```
+
+The action downloads the glint Linux binary into `$RUNNER_TEMP` and runs `glint check`. Only Linux runners are supported (matches the available release binary).
+
 ## Development
 
 This project uses [Task](https://taskfile.dev) as a task runner.
@@ -69,11 +119,18 @@ task test         # run Go unit tests
 task lint-go      # run go vet
 task validate     # run the binary against all testdata fixtures
 task ci           # full check: vet → test → build → validate
+task fuzz         # run fuzz tests for the YAML parser (Ctrl-C to stop; FUZZ_TIME=60s to set duration)
+task changelog    # regenerate CHANGELOG.md from git history via git-cliff
+task changelog-next  # preview unreleased section (dry-run, no file written)
 task build-windows  # cross-compile for Windows x64 (requires a tagged commit → glint-<tag>.exe)
 task build-linux    # cross-compile for Linux x64 (requires a tagged commit → glint-<tag>-linux-amd64)
 task clean        # remove build artifacts
 ```
 
+**Optional tools:**
+
+- [git-cliff](https://git-cliff.org) — changelog generator used by `task changelog`. Install with `brew install git-cliff` or `cargo install git-cliff`.
+
 ## Project structure
 
 ```

ROADMAP.md

@@ -8,23 +8,23 @@ This document tracks planned improvements to `glint`. Items are grouped by theme
 
 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.
 
-- ~~**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
-- ~~**`rules:changes:` evaluation**~~ — ✓ shipped v0.2.21; `--changes PATH` and `--changes-from REF` flags; doublestar glob matching (`*` within segment, `**` across segments); permissive when no file list provided
-- ~~**Multi-context simulation**~~ — ✓ shipped v0.2.22; `--context KEY=VALUE[,...]`; repeatable; prints a comparison table of `active`/`manual`/`skipped`/`blocked` per job across all contexts
-- ~~**Context-scoped linting**~~ — ✓ shipped v0.2.23; jobs evaluated as `JobSkipped` in the supplied context are excluded from `needs:`/`dependencies:` cross-checks (GL027–GL031) to eliminate false-positive errors for conditionally-gated jobs
+- [x] **Single-context simulation** — shipped v0.2.0; `--branch`, `--tag`, `--source`, `--var` flags on both subcommands; jobs classified as active / manual / skipped
+- [x] **`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
+- [x] **Expression evaluator: multi-line `if:` values** — shipped post-v0.2.0; newlines in block-scalar and folded YAML `if:` values treated as whitespace
+- [x] **Expression evaluator: `${VAR}` syntax** — shipped post-v0.2.0; `${CI_COMMIT_BRANCH}` equivalent to `$CI_COMMIT_BRANCH` everywhere
+- [x] **Expression evaluator: regex flags** — shipped post-v0.2.0; `/pattern/i`, `/pattern/m`, `/pattern/s` supported
+- [x] **Expression evaluator: variable as regex RHS** — shipped post-v0.2.0; `$BRANCH =~ $PATTERN` where `$PATTERN` holds a `/regex/` string evaluates correctly
+- [x] **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
+- [x] **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
+- [x] **`--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
+- [x] **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`
+- [x] **Non-string scalar variables** — shipped v0.2.13; `BUILD: true`, `RETRIES: 3` rendered and injected correctly instead of being silently dropped
+- [x] **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
+- [x] **Workflow rule strict evaluation** — shipped v0.2.14; unparseable `if:` skips the rule instead of matching everything; prevents wrong variables being injected
+- [x] **Single `=` operator** — shipped v0.2.14; bare `=` accepted as alias for `==` in `rules:if:` expressions
+- [x] **`rules:changes:` evaluation** — shipped v0.2.21; `--changes PATH` and `--changes-from REF` flags; doublestar glob matching (`*` within segment, `**` across segments); permissive when no file list provided
+- [x] **Multi-context simulation** — shipped v0.2.22; `--context KEY=VALUE[,...]`; repeatable; prints a comparison table of `active`/`manual`/`skipped`/`blocked` per job across all contexts
+- [x] **Context-scoped linting** — shipped v0.2.23; jobs evaluated as `JobSkipped` in the supplied context are excluded from `needs:`/`dependencies:` cross-checks (GL027–GL031) to eliminate false-positive errors for conditionally-gated jobs
 
 ---
 
@@ -32,36 +32,36 @@ Pass `--branch`, `--tag`, `--source`, or `--var` to `glint check` or `glint grap
 
 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 (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:`
+- [x] **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
+- [x] **`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
+- [x] **`services:` validation (GL034)** — shipped v0.2.16; map form requires `name`; `alias` must be a valid DNS label
+- [x] **`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
+- [x] **`timeout` format validation (GL036)** — shipped v0.2.16; validates job-level and `default.timeout` against recognised GitLab CI duration strings
+- [x] **`id_tokens:` / `secrets:` required-key checks (GL037, GL038)** — shipped v0.2.16; `id_tokens` entries must have `aud`; `secrets` entries must declare a provider
+- [x] **`pages:publish` + `artifacts.paths` consistency (GL039)** — shipped v0.2.16; warns when the publish directory is missing from `artifacts.paths`
+- [x] **Duplicate stage names (GL040)** — shipped v0.2.16; warns when a stage appears more than once in `stages:`
+- [x] **`cache:key:files` must be exact paths (GL041)** — shipped v0.2.16; warns when entries look like glob patterns
+- [x] **Unreachable jobs** — covered by GL033 (shipped v0.2.15); every-`when:never` rules block is statically dead
+- [x] **`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)~~ — ✓ 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
+- [x] **`include: local:` full resolution** — shipped v0.2.0; local files are read from disk, recursively resolved, and merged before linting
+- [x] **`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
+- [x] **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
+- [x] **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`
+- [x] **`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 — ✓ shipped v0.2.18
+## Output formats
 
-- ~~**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
+- [x] **JSON** (`--format json`) — shipped v0.2.18; machine-readable findings with stable schema (version 1)
+- [x] **SARIF** (`--format sarif`) — shipped v0.2.18; SARIF 2.1.0; consumed natively by GitHub Code Scanning and GitLab SAST
+- [x] **JUnit XML** (`--format junit`) — shipped v0.2.18; lets CI pipelines publish lint results as a test report artifact
+- [x] **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
 
 ---
 
@@ -69,55 +69,51 @@ The current rule set covers the most common sources of broken pipelines. These a
 
 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**~~ — ✓ shipped v0.2.25; classic mode uses a bus-bar pattern (vertical rail at the midpoint + horizontal stubs per job) instead of a single center-to-center line, so uneven columns look correct
-- ~~**Job tooltip / detail panel**~~ — ✓ shipped v0.2.25; each chip is wrapped in `<g data-job="…"><title>…</title><desc>…</desc>` — SVG viewers show stage, when, image, and needs on hover; HTML output uses the data for the sidebar
-- ~~**`when: on_failure` visual distinction**~~ — ✓ shipped v0.2.25; dashed chip border + X-mark icon + red circle (`#d9534f`); legend entry added; Mermaid `on_failure` class wired
-- ~~**Blocked / skipped state colouring**~~ — ✓ shipped v0.2.25; `glint graph pipeline` accepts context flags (`--branch`, `--tag`, etc.); jobs evaluated as skipped are greyed out (`#868686`) with dimmed text and no icon
-- ~~**Interactive HTML output**~~ — ✓ shipped v0.2.25; `glint graph pipeline --format html` writes a self-contained `.html` file with mouse pan/zoom and a click-to-open job-detail sidebar; no external dependencies
-- ~~**Mermaid pipeline output**~~ — ✓ shipped v0.2.25; `glint graph pipeline --format mermaid` prints a Mermaid flowchart to stdout (paste into mermaid.live)
-- ~~**Same-stage job ordering**~~ — ✓ shipped v0.2.26; jobs within a stage that have `needs:` between each other are placed in topological sub-columns (left-to-right by depth); stage header spans all sub-columns
-- ~~**Graph links rendered behind job chips**~~ — ✓ shipped v0.2.26; SVG connectors (Bézier curves and bus-bar stubs) are drawn before job chips so lines pass behind rectangles
+- [x] **Terminal job tree** — shipped v0.2.0 as `glint graph tree`; stages as branches, jobs as leaves, context-aware annotations
+- [x] **`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
+- [x] **Multi-job connector accuracy** — shipped v0.2.25; classic mode uses a bus-bar pattern (vertical rail at the midpoint + horizontal stubs per job) instead of a single center-to-center line, so uneven columns look correct
+- [x] **Job tooltip / detail panel** — shipped v0.2.25; each chip is wrapped in `<g data-job="…"><title>…</title><desc>…</desc>` — SVG viewers show stage, when, image, and needs on hover; HTML output uses the data for the sidebar
+- [x] **`when: on_failure` visual distinction** — shipped v0.2.25; dashed chip border + X-mark icon + red circle (`#d9534f`); legend entry added; Mermaid `on_failure` class wired
+- [x] **Blocked / skipped state colouring** — shipped v0.2.25; `glint graph pipeline` accepts context flags (`--branch`, `--tag`, etc.); jobs evaluated as skipped are greyed out (`#868686`) with dimmed text and no icon
+- [x] **Interactive HTML output** — shipped v0.2.25; `glint graph pipeline --format html` writes a self-contained `.html` file with mouse pan/zoom and a click-to-open job-detail sidebar; no external dependencies
+- [x] **Mermaid pipeline output** — shipped v0.2.25; `glint graph pipeline --format mermaid` prints a Mermaid flowchart to stdout (paste into mermaid.live)
+- [x] **Same-stage job ordering** — shipped v0.2.26; jobs within a stage that have `needs:` between each other are placed in topological sub-columns (left-to-right by depth); stage header spans all sub-columns
+- [x] **Graph links rendered behind job chips** — shipped v0.2.26; SVG connectors (Bézier curves and bus-bar stubs) are drawn before job chips so lines pass behind rectangles
 
 ---
 
-## Findings quality — ✓ file and line numbers shipped post-v0.2.0; ruff-style format shipped v0.2.11
+## Findings quality
 
-~~**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)
+- [x] **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
+- [x] **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
+- [x] **`needs: optional: true` false-positive errors** — shipped post-v0.2.0; optional missing needs are downgraded to `[WARNING]`
+- [x] **`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)
+- [x] **`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
-- **GitHub Actions action** — `uses: k3nny/glint@v1` wrapper for repositories that mirror or manage GitLab pipelines from GitHub
-- **Pre-commit hook** — entry for [pre-commit](https://pre-commit.com) so `glint` runs automatically on `git commit` when `.gitlab-ci.yml` changes
-- **LSP server** — `glint lsp` mode exposing diagnostics over the Language Server Protocol; enables inline squiggles in VS Code, JetBrains, Neovim, etc. without a dedicated extension
-- **VS Code extension** — thin wrapper around the LSP server with syntax highlighting for `.gitlab-ci.yml`
+- [x] **GitLab CI template** — shipped v0.2.28; `templates/check.yml` is a GitLab CI/CD Catalog component with `spec:` inputs for stage, file, version, allow_failure, and extra args; also usable as a plain local/remote include
+- [x] **GitHub Actions action** — shipped v0.2.28; `action.yml` composite action downloads the glint Linux binary and runs `glint check`; mirror to GitHub as `k3nny/glint` to reference as `uses: k3nny/glint@v0.2.28`
+- [x] **Pre-commit hook** — shipped v0.2.28; `.pre-commit-hooks.yaml` defines `language: golang` hook; pre-commit builds glint from source on first run and re-runs on staged `.gitlab-ci.yml` changes
+- [x] **LSP server** — shipped v0.2.29; `glint lsp` runs a JSON-RPC 2.0 LSP server over stdin/stdout; `textDocument/didOpen`, `didChange`, `didSave`, `didClose` all publish diagnostics; rule IDs appear as the diagnostic `code`; include resolution is best-effort using env-var token and default cache dir
+- [ ] **VS Code extension** — thin wrapper around the LSP server with syntax highlighting for `.gitlab-ci.yml`
 
 ---
 
-## Configuration — ✓ shipped v0.2.19
+## Configuration
 
-- ~~**`.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
+- [x] **`.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
+- [x] **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**~~ — ✓ 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; GL044 added v0.2.24; graph improvements shipped v0.2.25–v0.2.26
-- ~~**`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
-- **Fuzz testing** — add a `go test -fuzz` target for the YAML parser to harden it against malformed input
+- [x] **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 added v0.2.18; GL042–GL043 added v0.2.20; GL044 added v0.2.24; graph improvements shipped v0.2.25–v0.2.26
+- [x] **`glint explain <rule-id>`** — shipped v0.2.20; prints rule description, rationale, bad-YAML example, and fix; `glint explain` (no arg) lists all rules
+- [x] **Semantic versioning and first release** — shipped v0.1.0 (2026-06-07)
+- [x] **Subcommand CLI** — shipped v0.2.0 (2026-06-11); `glint check` / `glint graph [mode]` with ruff-style `--help`
+- [x] **Changelog automation** — shipped v0.2.27; `cliff.toml` configures git-cliff to produce Keep-a-Changelog–compatible release notes from Conventional Commits; `task changelog` regenerates `CHANGELOG.md`, `task changelog-next` previews unreleased entries
+- [x] **Fuzz testing** — shipped v0.2.27; `FuzzParseBytes` and `FuzzSanitizeYAMLEscapes` in `internal/model/fuzz_test.go`; seeds run as regular tests in CI; `task fuzz` runs them continuously (default 30 s)

Taskfile.yml

@@ -175,6 +175,23 @@ tasks:
     generates:
       - "{{.BINARY}}-{{.TAG}}-linux-amd64"
 
+  fuzz:
+    desc: "Run all fuzz targets (set FUZZ_TIME=60s to control per-target duration, default 30s)"
+    cmds:
+      - "{{.GO}} test -fuzz=FuzzParseBytes          -fuzztime=${FUZZ_TIME:-30s} ./internal/model/"
+      - "{{.GO}} test -fuzz=FuzzSanitizeYAMLEscapes -fuzztime=${FUZZ_TIME:-30s} ./internal/model/"
+      - "{{.GO}} test -fuzz=FuzzEvalIf              -fuzztime=${FUZZ_TIME:-30s} ./internal/cicontext/"
+      - "{{.GO}} test -fuzz=FuzzExpandVarRefs       -fuzztime=${FUZZ_TIME:-30s} ./internal/cicontext/"
+      - "{{.GO}} test -fuzz=FuzzLint                -fuzztime=${FUZZ_TIME:-30s} ./internal/linter/"
+
+  changelog:
+    desc: "Regenerate CHANGELOG.md from git history (requires git-cliff — see README)"
+    cmd: git cliff --config cliff.toml --output CHANGELOG.md
+
+  changelog-next:
+    desc: "Preview unreleased changelog entries without writing (requires git-cliff)"
+    cmd: git cliff --config cliff.toml --unreleased
+
   clean:
     desc: Remove build artifacts
     cmd: rm -f {{.BINARY}} {{.BINARY}}-*.exe {{.BINARY}}-*-linux-amd64

action.yml

@@ -0,0 +1,62 @@
+# GitHub Actions composite action — glint pipeline validator
+#
+# To use this action, mirror this repository to GitHub as k3nny/glint, then:
+#
+#   - uses: k3nny/glint@v0.2.28
+#     with:
+#       file: .gitlab-ci.yml   # optional
+#
+# Alternatively, copy this file into your own repository and reference it
+# as a local action:
+#
+#   - uses: ./.github/actions/glint
+
+name: 'glint'
+description: 'Validate a GitLab CI pipeline file with glint'
+author: 'k3nny'
+
+branding:
+  icon: 'check-circle'
+  color: 'orange'
+
+inputs:
+  version:
+    description: >-
+      glint release tag to install (e.g. 'v0.2.28'). Defaults to 'latest'
+      which resolves to the newest published release.
+    required: false
+    default: 'latest'
+  file:
+    description: 'Path to the pipeline file to validate.'
+    required: false
+    default: '.gitlab-ci.yml'
+  args:
+    description: 'Additional arguments passed to glint check (e.g. --format sarif).'
+    required: false
+    default: ''
+
+runs:
+  using: 'composite'
+  steps:
+    - name: Install glint
+      shell: bash
+      env:
+        GLINT_VERSION: ${{ inputs.version }}
+      run: |
+        set -euo pipefail
+        if [ "$GLINT_VERSION" = "latest" ]; then
+          GLINT_VERSION=$(curl -sf \
+            "https://git.k3nny.fr/api/v1/repos/k3nny/glint/releases?limit=1" \
+            | grep '"tag_name"' | head -1 | cut -d'"' -f4)
+        fi
+        DEST="$RUNNER_TEMP/glint-bin"
+        mkdir -p "$DEST"
+        URL="https://git.k3nny.fr/k3nny/glint/releases/download/${GLINT_VERSION}/glint-${GLINT_VERSION}-linux-amd64"
+        curl -sfL "$URL" -o "$DEST/glint"
+        chmod +x "$DEST/glint"
+        echo "$DEST" >> "$GITHUB_PATH"
+        "$DEST/glint" --version
+
+    - name: Run glint check
+      shell: bash
+      run: glint check ${{ inputs.args }} "${{ inputs.file }}"

cliff.toml

@@ -0,0 +1,65 @@
+# git-cliff configuration for glint
+# Install: brew install git-cliff  OR  cargo install git-cliff
+# Usage:   task changelog            -- regenerate full CHANGELOG.md
+#          task changelog-next       -- preview unreleased section (dry-run)
+
+[changelog]
+header = """
+# Changelog
+
+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).
+"""
+body = """
+{% if version %}\
+## [{{ version | trim_start_matches(pat="v") }}] - {{ timestamp | date(format="%Y-%m-%d") }}
+
+{% else %}\
+## [Unreleased]
+
+{% endif %}\
+{% for group, commits in commits | group_by(attribute="group") %}\
+### {{ group | upper_first }}
+
+{% for commit in commits %}\
+- {% if commit.scope %}**{{ commit.scope }}**: {% endif %}\
+{{ commit.message | upper_first }}\
+{% if commit.breaking %} **[BREAKING]**{% endif %}
+
+{% endfor %}\
+{% endfor %}\
+"""
+trim = true
+footer = ""
+postprocessors = []
+
+[git]
+conventional_commits = true
+filter_unconventional = true
+split_commits = false
+commit_preprocessors = [
+  # Drop Co-Authored-By trailers (should not appear in subjects, but guard anyway).
+  { pattern = "Co-Authored-By:.*", replace = "" },
+]
+commit_parsers = [
+  # Breaking changes (type! or scope!) — promote above everything else.
+  { message = "^[a-z]+\\([a-z-]+\\)!:|^[a-z]+!:", group = "Breaking Changes" },
+  { message = "^feat",     group = "Added" },
+  { message = "^fix",      group = "Fixed" },
+  { message = "^perf",     group = "Changed" },
+  { message = "^refactor", group = "Changed" },
+  # Maintenance commits — omit from the changelog body.
+  { message = "^docs",   skip = true },
+  { message = "^style",  skip = true },
+  { message = "^test",   skip = true },
+  { message = "^chore",  skip = true },
+  { message = "^build",  skip = true },
+  { message = "^claude", skip = true },
+]
+protect_breaking_commits = false
+filter_commits = true
+tag_pattern = "v[0-9].*"
+topo_order = false
+sort_commits = "oldest"

cmd/glint/lsp.go

@@ -0,0 +1,71 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+
+	"git.k3nny.fr/glint/internal/fetcher"
+	"git.k3nny.fr/glint/internal/lsp"
+)
+
+func cmdLSP(args []string) {
+	fs := flag.NewFlagSet("glint lsp", 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 for caching fetched remote includes")
+	offline := fs.Bool("offline", false, "skip all network calls; serve only from --cache-dir")
+	fs.Usage = func() {
+		fmt.Fprintf(os.Stderr, "glint %s\n\n", version)
+		fmt.Fprint(os.Stderr, `Start a Language Server Protocol server for .gitlab-ci.yml files.
+
+Reads JSON-RPC 2.0 messages from stdin and writes responses to stdout using
+the standard Content-Length framing. Connect with any LSP client (VS Code,
+Neovim, Emacs, etc.).
+
+Usage: glint lsp [OPTIONS]
+
+Options:
+      --token <TOKEN>
+          GitLab personal access token used for resolving project: and
+          component: includes. Defaults to GITLAB_TOKEN env var.
+
+      --gitlab-url <URL>
+          GitLab instance URL for resolving remote includes.
+          [env: CI_SERVER_URL | GITLAB_URL] [default: https://gitlab.com]
+
+      --cache-dir <DIR>
+          Cache directory for fetched remote includes. Defaults to
+          ~/.cache/glint so subsequent opens are served from cache.
+
+      --offline
+          Do not make any network calls; resolve only local includes.
+          Implies --cache-dir default (~/.cache/glint) when not set.
+
+  -h, --help
+          Print help
+
+Examples:
+  glint lsp
+  glint lsp --token glpat-xxxx --cache-dir ~/.cache/glint
+  glint lsp --offline
+`)
+	}
+	_ = fs.Parse(args)
+
+	resolvedCacheDir := *cacheDir
+	if resolvedCacheDir == "" {
+		resolvedCacheDir = defaultCacheDir()
+	}
+	if *offline && resolvedCacheDir == "" {
+		resolvedCacheDir = defaultCacheDir()
+	}
+
+	cfg := fetcher.AutoConfig().WithOverrides(*gitlabURL, *token, resolvedCacheDir, *offline)
+
+	srv := lsp.New(os.Stdin, os.Stdout, cfg, version)
+	if err := srv.Run(); err != nil {
+		fmt.Fprintf(os.Stderr, "glint lsp: %v\n", err)
+		exit(2)
+	}
+}

cmd/glint/main.go

@@ -69,6 +69,7 @@ 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)
+  lsp      Start a Language Server Protocol server (stdin/stdout)
 
 Options:
   -h, --help     Print help
@@ -90,6 +91,8 @@ func main() {
 		cmdGraph(os.Args[2:])
 	case "explain":
 		cmdExplain(os.Args[2:])
+	case "lsp":
+		cmdLSP(os.Args[2:])
 	case "-h", "--help", "help":
 		fmt.Fprintf(os.Stderr, "glint %s\n\n", version)
 		fmt.Fprint(os.Stderr, globalUsage)

go.mod

@@ -2,14 +2,15 @@ module git.k3nny.fr/glint
 
 go 1.26.4
 
+require gopkg.in/yaml.v3 v3.0.1
+
 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
+	golang.org/x/mod v0.35.0 // indirect
+	golang.org/x/sync v0.20.0 // indirect
+	golang.org/x/tools v0.44.1-0.20260420230617-19499e7caabc // indirect
+	honnef.co/go/tools v0.8.0-rc.1 // indirect
 )
 
 tool honnef.co/go/tools/cmd/staticcheck

go.sum

@@ -1,16 +1,20 @@
 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=
+github.com/google/go-cmp v0.7.0 h1:wk8382ETsv4JYUZwIsn6YpYiWiBsYLSJiTsyBybVuN8=
+github.com/google/go-cmp v0.7.0/go.mod h1:pXiqmnSA92OHEEa9HXL2W4E7lf9JzCmGVUdgjX3N/iU=
 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=
+golang.org/x/mod v0.35.0 h1:Ww1D637e6Pg+Zb2KrWfHQUnH2dQRLBQyAtpr/haaJeM=
+golang.org/x/mod v0.35.0/go.mod h1:+GwiRhIInF8wPm+4AoT6L0FA1QWAad3OMdTRx4tFYlU=
+golang.org/x/sync v0.20.0 h1:e0PTpb7pjO8GAtTs2dQ6jYa5BWYlMuX047Dco/pItO4=
+golang.org/x/sync v0.20.0/go.mod h1:9xrNwdLfx4jkKbNva9FpL6vEN7evnE43NNNJQ2LF3+0=
+golang.org/x/tools v0.44.1-0.20260420230617-19499e7caabc h1:vSv/HN1q9eoPD7lMyJYVJ/GPYnqtqu6adMxUmrxOB78=
+golang.org/x/tools v0.44.1-0.20260420230617-19499e7caabc/go.mod h1:KA0AfVErSdxRZIsOVipbv3rQhVXTnlU6UhKxHd1seDI=
+golang.org/x/tools/go/expect v0.1.1-deprecated h1:jpBZDwmgPhXsKZC6WhL20P4b/wmnpsEAGHaNy0n/rJM=
+golang.org/x/tools/go/expect v0.1.1-deprecated/go.mod h1:eihoPOH+FgIqa3FpoTwguz/bVUSGBlGQU67vpBeOrBY=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 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=
+honnef.co/go/tools v0.8.0-rc.1 h1:wqMm2kjcEXMOr+6yau+pdKqJKe6l2N1aKPkpini+Kzk=
+honnef.co/go/tools v0.8.0-rc.1/go.mod h1:XA+OnlRA9EDh/ukGvXMNSZNKGwFQJ+5dER0ioUkOxks=

internal/cicontext/fuzz_test.go

@@ -0,0 +1,85 @@
+package cicontext
+
+import "testing"
+
+// FuzzEvalIf ensures the rules:if: expression evaluator never panics on
+// arbitrary input. It accepts two strings: the expression and a variable value
+// substituted for every variable reference encountered.
+// Run with: go test -fuzz=FuzzEvalIf ./internal/cicontext/
+func FuzzEvalIf(f *testing.F) {
+	// Seed corpus: representative expressions exercising every code path in
+	// the hand-rolled recursive-descent parser.
+	seeds := []struct{ expr, varVal string }{
+		// Simple comparisons
+		{`$VAR == "main"`, "main"},
+		{`$VAR != "main"`, "main"},
+		{`$VAR == null`, ""},
+		{`$VAR != null`, "x"},
+		// Regex operators
+		{`$VAR =~ /^v\d+\.\d+/`, "v1.2.3"},
+		{`$VAR !~ /^v\d+\.\d+/`, "not-a-version"},
+		{`$VAR =~ /^us\//`, "us/west"},
+		// Boolean operators
+		{`$A == "x" && $B == "y"`, "x"},
+		{`$A == "x" || $B == "y"`, "z"},
+		{`!($VAR == "main")`, "main"},
+		// Nested parens
+		{`($VAR == "a" || $VAR == "b") && $VAR != "c"`, "a"},
+		// Bare true / false
+		{`$VAR == true`, "true"},
+		{`$VAR == false`, "false"},
+		// Integer comparison (GitLab CI compares as strings)
+		{`$VAR == 42`, "42"},
+		// Regex with flags
+		{`$VAR =~ /main/i`, "MAIN"},
+		// Syntax errors / incomplete expressions
+		{``, ""},
+		{`&&`, ""},
+		{`$VAR =~`, "x"},
+		{`($VAR`, "x"},
+		{`$VAR == `, "x"},
+		// Variable syntax variants
+		{`${VAR} == "main"`, "main"},
+		// Deeply nested
+		{`((($VAR == "a")))`, "a"},
+		// String with escapes
+		{`$VAR == "hello\nworld"`, "hello\nworld"},
+		// Null literal
+		{`null == null`, ""},
+		{`$VAR == null`, ""},
+	}
+	for _, s := range seeds {
+		f.Add(s.expr, s.varVal)
+	}
+
+	f.Fuzz(func(t *testing.T, expr, varVal string) {
+		// EvalIf must never panic; it may return any bool.
+		_ = EvalIf(expr, func(string) string { return varVal })
+		_ = EvalIfStrict(expr, func(string) string { return varVal })
+	})
+}
+
+// FuzzExpandVarRefs ensures variable expansion in expression strings never
+// panics and never produces a longer output than the worst-case expansion bound.
+func FuzzExpandVarRefs(f *testing.F) {
+	seeds := []struct{ s, val string }{
+		{"$VAR", "hello"},
+		{"${VAR}", "hello"},
+		{"$A $B $C", "x"},
+		{"no vars here", ""},
+		{"$$double", "x"},
+		{"$", "x"},
+		{"${", "x"},
+		{"${}", "x"},
+		{"prefix_$VAR_suffix", "mid"},
+		{"$1INVALID", "x"},
+	}
+	for _, s := range seeds {
+		f.Add(s.s, s.val)
+	}
+
+	f.Fuzz(func(t *testing.T, s, val string) {
+		vars := map[string]string{"VAR": val, "A": val, "B": val, "C": val}
+		_ = expandVarRefs(s, vars)
+	})
+}

internal/linter/fuzz_test.go

@@ -0,0 +1,69 @@
+package linter
+
+import (
+	"testing"
+
+	"git.k3nny.fr/glint/internal/model"
+)
+
+// FuzzLint ensures that the full Parse → Lint pipeline never panics on
+// arbitrary YAML input. Lint rules type-assert model fields extensively;
+// this fuzzer drives those assertions against malformed-but-parseable YAML.
+// Run with: go test -fuzz=FuzzLint ./internal/linter/
+func FuzzLint(f *testing.F) {
+	seeds := []string{
+		// Minimal valid pipeline
+		"stages: [build]\njob:\n  stage: build\n  script: echo ok\n",
+		// Manual / delayed / trigger / on_failure job types
+		"job:\n  script: ok\n  when: manual\n",
+		"job:\n  script: ok\n  when: delayed\n  start_in: 5 minutes\n",
+		"job:\n  trigger:\n    project: group/repo\n",
+		"job:\n  script: ok\n  when: on_failure\n",
+		// needs: and dependencies:
+		"stages: [a,b]\na:\n  stage: a\n  script: ok\nb:\n  stage: b\n  needs: [a]\n  script: ok\n",
+		"stages: [a,b]\na:\n  stage: a\n  script: ok\nb:\n  stage: b\n  dependencies: [a]\n  script: ok\n",
+		// rules:
+		"job:\n  script: ok\n  rules:\n    - if: '$CI_COMMIT_BRANCH == \"main\"'\n      when: on_success\n",
+		// parallel matrix
+		"job:\n  script: ok\n  parallel:\n    matrix:\n      - ARCH: [amd64, arm64]\n",
+		// image as string / map
+		"job:\n  script: ok\n  image: golang:1.21\n",
+		"job:\n  script: ok\n  image:\n    name: golang:1.21\n    entrypoint: ['']\n",
+		// artifacts / cache with both string and map when:
+		"job:\n  script: ok\n  artifacts:\n    when: on_success\n    paths: [dist/]\n",
+		"job:\n  script: ok\n  cache:\n    key: $CI_COMMIT_REF_SLUG\n    paths: [vendor/]\n",
+		// environment / release / coverage
+		"job:\n  script: ok\n  environment:\n    name: production\n    url: https://example.com\n",
+		"job:\n  script: ok\n  release:\n    tag_name: $CI_COMMIT_TAG\n    description: Release\n",
+		"job:\n  script: ok\n  coverage: '/^TOTAL.*?(\\d+%)$/'\n",
+		// retry / timeout
+		"job:\n  script: ok\n  retry: 2\n",
+		"job:\n  script: ok\n  timeout: 2h30m\n",
+		// workflow
+		"workflow:\n  rules:\n    - if: '$CI_COMMIT_BRANCH'\n      when: always\njob:\n  script: ok\n",
+		// extends
+		".base:\n  script: ok\nchild:\n  extends: .base\n  stage: test\n",
+		// id_tokens / secrets
+		"job:\n  script: ok\n  id_tokens:\n    TOKEN:\n      aud: https://example.com\n",
+		// services
+		"job:\n  script: ok\n  services:\n    - name: postgres:14\n      alias: db\n",
+		// pages job
+		"pages:\n  script: make docs\n  artifacts:\n    paths: [public/]\n",
+		// inherit
+		"default:\n  retry: 1\njob:\n  script: ok\n  inherit:\n    default: false\n",
+		// allow_failure
+		"job:\n  script: ok\n  allow_failure:\n    exit_codes: [1, 2]\n",
+	}
+	for _, s := range seeds {
+		f.Add([]byte(s))
+	}
+
+	f.Fuzz(func(t *testing.T, data []byte) {
+		p, err := model.ParseBytes(data)
+		if err != nil {
+			return
+		}
+		// Lint must never panic regardless of pipeline content.
+		_ = Lint(p, nil)
+	})
+}

internal/lsp/server.go

@@ -0,0 +1,332 @@
+package lsp
+
+import (
+	"bufio"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/url"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+
+	"git.k3nny.fr/glint/internal/fetcher"
+	"git.k3nny.fr/glint/internal/linter"
+	"git.k3nny.fr/glint/internal/model"
+	"git.k3nny.fr/glint/internal/resolver"
+)
+
+// Server is a minimal Language Server Protocol server that publishes glint
+// diagnostics for .gitlab-ci.yml files opened in an editor.
+//
+// Transport: JSON-RPC 2.0 over stdin/stdout with Content-Length framing.
+// Sync mode: Full — the client sends the complete document text on every change.
+type Server struct {
+	in      *bufio.Reader
+	out     io.Writer
+	cfg     fetcher.GitLabConfig
+	version string
+	docs    map[string]string // uri → current document text
+
+	// Exit is called with the process exit code when the LSP client sends the
+	// "exit" notification. Defaults to os.Exit; replace in tests.
+	Exit func(int)
+
+	shutdownReceived bool
+}
+
+// New creates a Server reading from r and writing to w.
+func New(r io.Reader, w io.Writer, cfg fetcher.GitLabConfig, version string) *Server {
+	return &Server{
+		in:      bufio.NewReader(r),
+		out:     w,
+		cfg:     cfg,
+		version: version,
+		docs:    make(map[string]string),
+		Exit:    os.Exit,
+	}
+}
+
+// Run processes LSP messages until the connection closes or a fatal error occurs.
+// It returns nil on a clean EOF (client disconnected) and a non-nil error for
+// unrecoverable protocol failures.
+func (s *Server) Run() error {
+	for {
+		msg, err := s.readMessage()
+		if err == io.EOF {
+			return nil
+		}
+		if err != nil {
+			return fmt.Errorf("reading LSP message: %w", err)
+		}
+		if err := s.dispatch(msg); err != nil {
+			return err
+		}
+	}
+}
+
+// readMessage reads one Content-Length–framed JSON-RPC message from the stream.
+func (s *Server) readMessage() (*Message, error) {
+	var contentLength int
+	for {
+		line, err := s.in.ReadString('\n')
+		if err != nil {
+			if err == io.EOF && line == "" {
+				return nil, io.EOF
+			}
+			return nil, err
+		}
+		line = strings.TrimRight(line, "\r\n")
+		if line == "" {
+			break // blank line separates headers from body
+		}
+		if strings.HasPrefix(line, "Content-Length: ") {
+			n, parseErr := strconv.Atoi(strings.TrimPrefix(line, "Content-Length: "))
+			if parseErr != nil {
+				return nil, fmt.Errorf("invalid Content-Length: %w", parseErr)
+			}
+			contentLength = n
+		}
+	}
+	if contentLength == 0 {
+		return nil, fmt.Errorf("missing or zero Content-Length header")
+	}
+
+	body := make([]byte, contentLength)
+	if _, err := io.ReadFull(s.in, body); err != nil {
+		return nil, fmt.Errorf("reading message body: %w", err)
+	}
+
+	var msg Message
+	if err := json.Unmarshal(body, &msg); err != nil {
+		return nil, fmt.Errorf("unmarshalling message: %w", err)
+	}
+	return &msg, nil
+}
+
+// writeMessage encodes v as JSON and sends it with a Content-Length header.
+func (s *Server) writeMessage(v any) error {
+	body, err := json.Marshal(v)
+	if err != nil {
+		return err
+	}
+	header := fmt.Sprintf("Content-Length: %d\r\n\r\n", len(body))
+	if _, err := io.WriteString(s.out, header); err != nil {
+		return err
+	}
+	_, err = s.out.Write(body)
+	return err
+}
+
+func (s *Server) respond(id json.RawMessage, result any) error {
+	raw, err := json.Marshal(result)
+	if err != nil {
+		return err
+	}
+	return s.writeMessage(struct {
+		JSONRPC string          `json:"jsonrpc"`
+		ID      json.RawMessage `json:"id"`
+		Result  json.RawMessage `json:"result"`
+	}{"2.0", id, raw})
+}
+
+func (s *Server) respondError(id json.RawMessage, code int, message string) error {
+	return s.writeMessage(struct {
+		JSONRPC string          `json:"jsonrpc"`
+		ID      json.RawMessage `json:"id"`
+		Error   RPCError        `json:"error"`
+	}{"2.0", id, RPCError{Code: code, Message: message}})
+}
+
+func (s *Server) notify(method string, params any) error {
+	raw, err := json.Marshal(params)
+	if err != nil {
+		return err
+	}
+	return s.writeMessage(struct {
+		JSONRPC string          `json:"jsonrpc"`
+		Method  string          `json:"method"`
+		Params  json.RawMessage `json:"params"`
+	}{"2.0", method, raw})
+}
+
+// isRequest reports whether msg is a JSON-RPC request (has a non-null id).
+func isRequest(msg *Message) bool {
+	return len(msg.ID) > 0 && string(msg.ID) != "null"
+}
+
+func (s *Server) dispatch(msg *Message) error {
+	switch msg.Method {
+	case "initialize":
+		return s.handleInitialize(msg)
+	case "initialized":
+		return nil // notification; no response required
+	case "shutdown":
+		s.shutdownReceived = true
+		if isRequest(msg) {
+			return s.respond(msg.ID, nil)
+		}
+		return nil
+	case "exit":
+		code := 1
+		if s.shutdownReceived {
+			code = 0
+		}
+		s.Exit(code)
+		return nil
+	case "textDocument/didOpen":
+		return s.handleDidOpen(msg)
+	case "textDocument/didChange":
+		return s.handleDidChange(msg)
+	case "textDocument/didSave":
+		return s.handleDidSave(msg)
+	case "textDocument/didClose":
+		return s.handleDidClose(msg)
+	default:
+		if isRequest(msg) {
+			return s.respondError(msg.ID, -32601, "method not found: "+msg.Method)
+		}
+		return nil
+	}
+}
+
+func (s *Server) handleInitialize(msg *Message) error {
+	return s.respond(msg.ID, InitializeResult{
+		Capabilities: ServerCapabilities{TextDocumentSync: 1},
+		ServerInfo:   &ServerInfo{Name: "glint", Version: s.version},
+	})
+}
+
+func (s *Server) handleDidOpen(msg *Message) error {
+	var p DidOpenTextDocumentParams
+	if err := json.Unmarshal(msg.Params, &p); err != nil {
+		return nil // ignore malformed notifications
+	}
+	s.docs[p.TextDocument.URI] = p.TextDocument.Text
+	return s.lintAndPublish(p.TextDocument.URI, p.TextDocument.Text)
+}
+
+func (s *Server) handleDidChange(msg *Message) error {
+	var p DidChangeTextDocumentParams
+	if err := json.Unmarshal(msg.Params, &p); err != nil {
+		return nil
+	}
+	if len(p.ContentChanges) == 0 {
+		return nil
+	}
+	// Full sync: the last change event holds the complete new text.
+	text := p.ContentChanges[len(p.ContentChanges)-1].Text
+	s.docs[p.TextDocument.URI] = text
+	return s.lintAndPublish(p.TextDocument.URI, text)
+}
+
+func (s *Server) handleDidSave(msg *Message) error {
+	var p DidSaveTextDocumentParams
+	if err := json.Unmarshal(msg.Params, &p); err != nil {
+		return nil
+	}
+	text := s.docs[p.TextDocument.URI]
+	if p.Text != nil {
+		text = *p.Text
+		s.docs[p.TextDocument.URI] = text
+	}
+	if text == "" {
+		return nil
+	}
+	return s.lintAndPublish(p.TextDocument.URI, text)
+}
+
+func (s *Server) handleDidClose(msg *Message) error {
+	var p DidCloseTextDocumentParams
+	if err := json.Unmarshal(msg.Params, &p); err != nil {
+		return nil
+	}
+	delete(s.docs, p.TextDocument.URI)
+	// Clear diagnostics so the editor doesn't show stale squiggles.
+	return s.notify("textDocument/publishDiagnostics", PublishDiagnosticsParams{
+		URI:         p.TextDocument.URI,
+		Diagnostics: []Diagnostic{},
+	})
+}
+
+func (s *Server) lintAndPublish(uri, text string) error {
+	diags := s.lintDocument(uri, text)
+	return s.notify("textDocument/publishDiagnostics", PublishDiagnosticsParams{
+		URI:         uri,
+		Diagnostics: diags,
+	})
+}
+
+// lintDocument parses text and runs all lint rules, returning LSP Diagnostics.
+// Findings that originate from included files (not the root document) are
+// excluded; their URIs are not tracked so line numbers would be incorrect.
+func (s *Server) lintDocument(uri, text string) []Diagnostic {
+	path := uriToPath(uri)
+	if path == "" {
+		return []Diagnostic{}
+	}
+	rootDir := filepath.Dir(filepath.Clean(path))
+
+	pipeline, err := model.ParseBytes([]byte(text))
+	if err != nil {
+		return []Diagnostic{{
+			Range:    Range{Start: Position{}, End: Position{}},
+			Severity: 1,
+			Source:   "glint",
+			Message:  "YAML parse error: " + err.Error(),
+		}}
+	}
+	pipeline.SourceFile = path
+	pipeline.SetJobOrigin(path)
+
+	// Include resolution is best-effort: network failures produce warnings that
+	// are intentionally discarded here. The linter operates on whatever was
+	// successfully resolved.
+	_, _ = resolver.ResolveIncludes(pipeline, s.cfg, rootDir)
+	_, _ = resolver.Resolve(pipeline)
+
+	findings := linter.Lint(pipeline, nil)
+
+	diags := make([]Diagnostic, 0, len(findings))
+	for _, f := range findings {
+		// Skip findings from included files — their line numbers reference
+		// a different document URI that the server has not opened.
+		if f.File != path && f.File != "" {
+			continue
+		}
+		line := 0
+		if f.Line > 0 {
+			line = f.Line - 1 // glint uses 1-based lines; LSP uses 0-based
+		}
+		sev := 1 // DiagnosticSeverity: Error
+		if f.Severity == linter.Warning {
+			sev = 2 // DiagnosticSeverity: Warning
+		}
+		msg := f.Message
+		if f.Job != "" {
+			msg = fmt.Sprintf("job %q: %s", f.Job, f.Message)
+		}
+		diags = append(diags, Diagnostic{
+			Range: Range{
+				Start: Position{Line: line},
+				End:   Position{Line: line},
+			},
+			Severity: sev,
+			Code:     f.Rule,
+			Source:   "glint",
+			Message:  msg,
+		})
+	}
+	return diags
+}
+
+// uriToPath converts a file:// URI to a local filesystem path.
+// Returns an empty string for non-file URIs or on parse error.
+func uriToPath(uri string) string {
+	u, err := url.Parse(uri)
+	if err != nil || u.Scheme != "file" {
+		return ""
+	}
+	return filepath.FromSlash(u.Path)
+}

internal/lsp/server_test.go

@@ -0,0 +1,383 @@
+package lsp
+
+import (
+	"bufio"
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"strconv"
+	"strings"
+	"testing"
+
+	"git.k3nny.fr/glint/internal/fetcher"
+)
+
+// frame encodes v as a Content-Length–framed LSP message.
+func frame(t *testing.T, v any) []byte {
+	t.Helper()
+	body, err := json.Marshal(v)
+	if err != nil {
+		t.Fatal(err)
+	}
+	hdr := fmt.Sprintf("Content-Length: %d\r\n\r\n", len(body))
+	return append([]byte(hdr), body...)
+}
+
+// readMsg reads one Content-Length–framed JSON object from r.
+func readMsg(t *testing.T, r *bufio.Reader) map[string]json.RawMessage {
+	t.Helper()
+	var contentLength int
+	for {
+		line, err := r.ReadString('\n')
+		if err != nil {
+			t.Fatalf("reading header: %v", err)
+		}
+		line = strings.TrimRight(line, "\r\n")
+		if line == "" {
+			break
+		}
+		if strings.HasPrefix(line, "Content-Length: ") {
+			n, err := strconv.Atoi(strings.TrimPrefix(line, "Content-Length: "))
+			if err != nil {
+				t.Fatalf("invalid Content-Length: %v", err)
+			}
+			contentLength = n
+		}
+	}
+	body := make([]byte, contentLength)
+	if _, err := io.ReadFull(r, body); err != nil {
+		t.Fatalf("reading body: %v", err)
+	}
+	var m map[string]json.RawMessage
+	if err := json.Unmarshal(body, &m); err != nil {
+		t.Fatalf("unmarshal: %v", err)
+	}
+	return m
+}
+
+// newTestServer returns a Server with a captured exit code and a bufio.Reader
+// wrapping the output buffer so tests can read back server messages.
+func newTestServer(input []byte) (*Server, *bytes.Buffer, *int) {
+	var out bytes.Buffer
+	exitCode := -1
+	srv := New(bytes.NewReader(input), &out, fetcher.GitLabConfig{}, "test")
+	srv.Exit = func(code int) { exitCode = code }
+	return srv, &out, &exitCode
+}
+
+func TestServer_Initialize(t *testing.T) {
+	input := frame(t, map[string]any{
+		"jsonrpc": "2.0",
+		"id":      1,
+		"method":  "initialize",
+		"params":  map[string]any{},
+	})
+	srv, out, _ := newTestServer(input)
+	srv.Run() //nolint:errcheck
+
+	resp := readMsg(t, bufio.NewReader(out))
+	if string(resp["id"]) != "1" {
+		t.Errorf("response id = %s; want 1", resp["id"])
+	}
+
+	var result InitializeResult
+	if err := json.Unmarshal(resp["result"], &result); err != nil {
+		t.Fatalf("unmarshal result: %v", err)
+	}
+	if result.Capabilities.TextDocumentSync != 1 {
+		t.Errorf("textDocumentSync = %d; want 1", result.Capabilities.TextDocumentSync)
+	}
+	if result.ServerInfo == nil || result.ServerInfo.Name != "glint" {
+		t.Errorf("serverInfo.name = %v; want glint", result.ServerInfo)
+	}
+}
+
+func TestServer_ShutdownExit(t *testing.T) {
+	var buf bytes.Buffer
+	buf.Write(frame(t, map[string]any{
+		"jsonrpc": "2.0", "id": 1, "method": "initialize", "params": map[string]any{},
+	}))
+	buf.Write(frame(t, map[string]any{
+		"jsonrpc": "2.0", "method": "initialized", "params": map[string]any{},
+	}))
+	buf.Write(frame(t, map[string]any{
+		"jsonrpc": "2.0", "id": 2, "method": "shutdown",
+	}))
+	buf.Write(frame(t, map[string]any{
+		"jsonrpc": "2.0", "method": "exit",
+	}))
+
+	srv, out, exitCode := newTestServer(buf.Bytes())
+	srv.Run() //nolint:errcheck
+
+	r := bufio.NewReader(out)
+	initResp := readMsg(t, r)
+	if string(initResp["id"]) != "1" {
+		t.Errorf("init response id = %s; want 1", initResp["id"])
+	}
+	shutResp := readMsg(t, r)
+	if string(shutResp["id"]) != "2" {
+		t.Errorf("shutdown response id = %s; want 2", shutResp["id"])
+	}
+	if string(shutResp["result"]) != "null" {
+		t.Errorf("shutdown result = %s; want null", shutResp["result"])
+	}
+	if *exitCode != 0 {
+		t.Errorf("exit code = %d; want 0", *exitCode)
+	}
+}
+
+func TestServer_ExitWithoutShutdown(t *testing.T) {
+	input := frame(t, map[string]any{
+		"jsonrpc": "2.0", "method": "exit",
+	})
+	srv, _, exitCode := newTestServer(input)
+	srv.Run() //nolint:errcheck
+
+	if *exitCode != 1 {
+		t.Errorf("exit code = %d; want 1 (no prior shutdown)", *exitCode)
+	}
+}
+
+func TestServer_MethodNotFound(t *testing.T) {
+	input := frame(t, map[string]any{
+		"jsonrpc": "2.0", "id": 99, "method": "workspace/unknownMethod",
+	})
+	srv, out, _ := newTestServer(input)
+	srv.Run() //nolint:errcheck
+
+	resp := readMsg(t, bufio.NewReader(out))
+	if resp["error"] == nil {
+		t.Errorf("expected error response for unknown method, got: %v", resp)
+	}
+	var rpcErr RPCError
+	if err := json.Unmarshal(resp["error"], &rpcErr); err != nil {
+		t.Fatalf("unmarshal error: %v", err)
+	}
+	if rpcErr.Code != -32601 {
+		t.Errorf("error code = %d; want -32601", rpcErr.Code)
+	}
+}
+
+func TestServer_UnknownNotificationIgnored(t *testing.T) {
+	// Notifications (no id) for unknown methods must be silently ignored.
+	input := frame(t, map[string]any{
+		"jsonrpc": "2.0", "method": "$/setTrace", "params": map[string]any{"value": "off"},
+	})
+	srv, out, _ := newTestServer(input)
+	srv.Run() //nolint:errcheck
+
+	if out.Len() > 0 {
+		t.Errorf("server wrote %d bytes for unknown notification; want 0", out.Len())
+	}
+}
+
+func TestServer_DidOpen_CleanPipeline(t *testing.T) {
+	yaml := `stages: [build]
+
+build-job:
+  stage: build
+  script: echo hello
+`
+	// Use a pseudo file:// URI that maps to the tmp path; include resolution
+	// will fail silently (no network, no local includes) which is fine.
+	uri := "file:///tmp/test.gitlab-ci.yml"
+
+	input := frame(t, map[string]any{
+		"jsonrpc": "2.0",
+		"method":  "textDocument/didOpen",
+		"params": map[string]any{
+			"textDocument": map[string]any{
+				"uri": uri, "languageId": "yaml", "version": 1, "text": yaml,
+			},
+		},
+	})
+	srv, out, _ := newTestServer(input)
+	srv.Run() //nolint:errcheck
+
+	notif := readMsg(t, bufio.NewReader(out))
+	if string(notif["method"]) != `"textDocument/publishDiagnostics"` {
+		t.Fatalf("method = %s; want textDocument/publishDiagnostics", notif["method"])
+	}
+	var params PublishDiagnosticsParams
+	if err := json.Unmarshal(notif["params"], &params); err != nil {
+		t.Fatalf("unmarshal params: %v", err)
+	}
+	if params.URI != uri {
+		t.Errorf("uri = %q; want %q", params.URI, uri)
+	}
+	// A clean pipeline should produce no diagnostics (or only warnings from
+	// include resolution being skipped — but those are filtered since they
+	// originate from a different file path).
+	for _, d := range params.Diagnostics {
+		if d.Severity == 1 {
+			t.Errorf("unexpected error diagnostic: %s", d.Message)
+		}
+	}
+}
+
+func TestServer_DidOpen_WithErrors(t *testing.T) {
+	// A pipeline with a job in an undeclared stage triggers GL004.
+	yaml := `stages: [build]
+
+bad-job:
+  stage: missing-stage
+  script: echo hi
+`
+	uri := "file:///tmp/bad.gitlab-ci.yml"
+	input := frame(t, map[string]any{
+		"jsonrpc": "2.0",
+		"method":  "textDocument/didOpen",
+		"params": map[string]any{
+			"textDocument": map[string]any{
+				"uri": uri, "languageId": "yaml", "version": 1, "text": yaml,
+			},
+		},
+	})
+	srv, out, _ := newTestServer(input)
+	srv.Run() //nolint:errcheck
+
+	notif := readMsg(t, bufio.NewReader(out))
+	var params PublishDiagnosticsParams
+	if err := json.Unmarshal(notif["params"], &params); err != nil {
+		t.Fatalf("unmarshal params: %v", err)
+	}
+	if len(params.Diagnostics) == 0 {
+		t.Error("expected diagnostics for pipeline with unknown stage, got none")
+	}
+	found := false
+	for _, d := range params.Diagnostics {
+		if d.Code == "GL004" {
+			found = true
+			if d.Severity != 1 {
+				t.Errorf("GL004 severity = %d; want 1 (Error)", d.Severity)
+			}
+		}
+	}
+	if !found {
+		t.Errorf("expected GL004 diagnostic, got: %v", params.Diagnostics)
+	}
+}
+
+func TestServer_DidOpen_ParseError(t *testing.T) {
+	uri := "file:///tmp/broken.gitlab-ci.yml"
+	input := frame(t, map[string]any{
+		"jsonrpc": "2.0",
+		"method":  "textDocument/didOpen",
+		"params": map[string]any{
+			"textDocument": map[string]any{
+				"uri": uri, "languageId": "yaml", "version": 1,
+				"text": "?", // bare ? yields empty job name → parse error
+			},
+		},
+	})
+	srv, out, _ := newTestServer(input)
+	srv.Run() //nolint:errcheck
+
+	notif := readMsg(t, bufio.NewReader(out))
+	var params PublishDiagnosticsParams
+	if err := json.Unmarshal(notif["params"], &params); err != nil {
+		t.Fatalf("unmarshal params: %v", err)
+	}
+	if len(params.Diagnostics) == 0 {
+		t.Fatal("expected parse-error diagnostic, got none")
+	}
+	d := params.Diagnostics[0]
+	if d.Severity != 1 {
+		t.Errorf("severity = %d; want 1 (Error)", d.Severity)
+	}
+	if !strings.Contains(d.Message, "YAML parse error") {
+		t.Errorf("message = %q; want YAML parse error", d.Message)
+	}
+}
+
+func TestServer_DidChange(t *testing.T) {
+	uri := "file:///tmp/ci.gitlab-ci.yml"
+	var buf bytes.Buffer
+	// Open with clean content.
+	buf.Write(frame(t, map[string]any{
+		"jsonrpc": "2.0", "method": "textDocument/didOpen",
+		"params": map[string]any{"textDocument": map[string]any{
+			"uri": uri, "languageId": "yaml", "version": 1,
+			"text": "stages: [build]\nbuild: {stage: build, script: echo}\n",
+		}},
+	}))
+	// Change to content with an error.
+	buf.Write(frame(t, map[string]any{
+		"jsonrpc": "2.0", "method": "textDocument/didChange",
+		"params": map[string]any{
+			"textDocument": map[string]any{"uri": uri, "version": 2},
+			"contentChanges": []map[string]any{
+				{"text": "stages: [build]\nbad: {stage: gone, script: hi}\n"},
+			},
+		},
+	}))
+
+	srv, out, _ := newTestServer(buf.Bytes())
+	srv.Run() //nolint:errcheck
+
+	r := bufio.NewReader(out)
+	_ = readMsg(t, r) // first publishDiagnostics (clean)
+	second := readMsg(t, r)
+
+	var params PublishDiagnosticsParams
+	if err := json.Unmarshal(second["params"], &params); err != nil {
+		t.Fatalf("unmarshal: %v", err)
+	}
+	if len(params.Diagnostics) == 0 {
+		t.Error("expected diagnostics after change to broken content, got none")
+	}
+}
+
+func TestServer_DidClose_ClearsdiAgnostics(t *testing.T) {
+	uri := "file:///tmp/toclose.gitlab-ci.yml"
+	var buf bytes.Buffer
+	buf.Write(frame(t, map[string]any{
+		"jsonrpc": "2.0", "method": "textDocument/didOpen",
+		"params": map[string]any{"textDocument": map[string]any{
+			"uri": uri, "languageId": "yaml", "version": 1,
+			"text": "stages: [build]\nj: {stage: build, script: echo}\n",
+		}},
+	}))
+	buf.Write(frame(t, map[string]any{
+		"jsonrpc": "2.0", "method": "textDocument/didClose",
+		"params": map[string]any{"textDocument": map[string]any{"uri": uri}},
+	}))
+
+	srv, out, _ := newTestServer(buf.Bytes())
+	srv.Run() //nolint:errcheck
+
+	r := bufio.NewReader(out)
+	_ = readMsg(t, r) // publishDiagnostics from didOpen
+
+	closeNotif := readMsg(t, r)
+	var params PublishDiagnosticsParams
+	if err := json.Unmarshal(closeNotif["params"], &params); err != nil {
+		t.Fatalf("unmarshal: %v", err)
+	}
+	if params.URI != uri {
+		t.Errorf("uri = %q; want %q", params.URI, uri)
+	}
+	if len(params.Diagnostics) != 0 {
+		t.Errorf("expected empty diagnostics on close, got %v", params.Diagnostics)
+	}
+}
+
+func TestServer_UriToPath(t *testing.T) {
+	tests := []struct {
+		uri  string
+		want string
+	}{
+		{"file:///tmp/ci.yml", "/tmp/ci.yml"},
+		{"file:///home/user/project/.gitlab-ci.yml", "/home/user/project/.gitlab-ci.yml"},
+		{"https://example.com/file.yml", ""},
+		{"not-a-uri", ""},
+	}
+	for _, tc := range tests {
+		got := uriToPath(tc.uri)
+		if got != tc.want {
+			t.Errorf("uriToPath(%q) = %q; want %q", tc.uri, got, tc.want)
+		}
+	}
+}

internal/lsp/types.go

@@ -0,0 +1,112 @@
+// Package lsp implements a minimal Language Server Protocol server for glint.
+package lsp
+
+import "encoding/json"
+
+// Message is a JSON-RPC 2.0 message (request, response, or notification).
+type Message struct {
+	JSONRPC string          `json:"jsonrpc"`
+	ID      json.RawMessage `json:"id,omitempty"`
+	Method  string          `json:"method,omitempty"`
+	Params  json.RawMessage `json:"params,omitempty"`
+	Result  json.RawMessage `json:"result,omitempty"`
+	Error   *RPCError       `json:"error,omitempty"`
+}
+
+// RPCError is a JSON-RPC 2.0 error object.
+type RPCError struct {
+	Code    int    `json:"code"`
+	Message string `json:"message"`
+}
+
+// InitializeResult is the server's response to the initialize request.
+type InitializeResult struct {
+	Capabilities ServerCapabilities `json:"capabilities"`
+	ServerInfo   *ServerInfo        `json:"serverInfo,omitempty"`
+}
+
+// ServerCapabilities advertises what the server supports.
+type ServerCapabilities struct {
+	// TextDocumentSync: 1 = Full (send entire document on every change).
+	TextDocumentSync int `json:"textDocumentSync"`
+}
+
+// ServerInfo identifies the server to the client.
+type ServerInfo struct {
+	Name    string `json:"name"`
+	Version string `json:"version,omitempty"`
+}
+
+// TextDocumentItem is a text document opened by the client.
+type TextDocumentItem struct {
+	URI        string `json:"uri"`
+	LanguageID string `json:"languageId"`
+	Version    int    `json:"version"`
+	Text       string `json:"text"`
+}
+
+// TextDocumentIdentifier references a text document by URI.
+type TextDocumentIdentifier struct {
+	URI string `json:"uri"`
+}
+
+// VersionedTextDocumentIdentifier includes a version number.
+type VersionedTextDocumentIdentifier struct {
+	URI     string `json:"uri"`
+	Version int    `json:"version"`
+}
+
+// TextDocumentContentChangeEvent is a single content change event.
+// With Full sync the Text field contains the complete new document text.
+type TextDocumentContentChangeEvent struct {
+	Text string `json:"text"`
+}
+
+// DidOpenTextDocumentParams is the params for textDocument/didOpen.
+type DidOpenTextDocumentParams struct {
+	TextDocument TextDocumentItem `json:"textDocument"`
+}
+
+// DidChangeTextDocumentParams is the params for textDocument/didChange.
+type DidChangeTextDocumentParams struct {
+	TextDocument   VersionedTextDocumentIdentifier  `json:"textDocument"`
+	ContentChanges []TextDocumentContentChangeEvent `json:"contentChanges"`
+}
+
+// DidSaveTextDocumentParams is the params for textDocument/didSave.
+type DidSaveTextDocumentParams struct {
+	TextDocument TextDocumentIdentifier `json:"textDocument"`
+	Text         *string                `json:"text,omitempty"`
+}
+
+// DidCloseTextDocumentParams is the params for textDocument/didClose.
+type DidCloseTextDocumentParams struct {
+	TextDocument TextDocumentIdentifier `json:"textDocument"`
+}
+
+// PublishDiagnosticsParams is the params for textDocument/publishDiagnostics.
+type PublishDiagnosticsParams struct {
+	URI         string       `json:"uri"`
+	Diagnostics []Diagnostic `json:"diagnostics"`
+}
+
+// Diagnostic is a lint finding expressed in LSP terms.
+type Diagnostic struct {
+	Range    Range  `json:"range"`
+	Severity int    `json:"severity"` // 1=Error, 2=Warning, 3=Information, 4=Hint
+	Code     string `json:"code,omitempty"`
+	Source   string `json:"source,omitempty"`
+	Message  string `json:"message"`
+}
+
+// Range is a zero-based line/character range within a text document.
+type Range struct {
+	Start Position `json:"start"`
+	End   Position `json:"end"`
+}
+
+// Position is a zero-based line and character offset.
+type Position struct {
+	Line      int `json:"line"`
+	Character int `json:"character"`
+}

internal/model/fuzz_test.go

@@ -0,0 +1,78 @@
+package model
+
+import "testing"
+
+// FuzzParseBytes ensures the YAML parser never panics on arbitrary input and
+// that successful parses return a structurally sound Pipeline.
+// Run with: go test -fuzz=FuzzParseBytes ./internal/model/
+// Found failures are saved to testdata/fuzz/FuzzParseBytes/.
+func FuzzParseBytes(f *testing.F) {
+	// Seed corpus: representative inputs covering the main code paths in
+	// ParseBytes, including the sanitizeYAMLEscapes pre-processing step.
+	seeds := [][]byte{
+		{},
+		[]byte("null"),
+		[]byte("stages: [build]\nbuild-job:\n  stage: build\n  script: echo ok\n"),
+		[]byte(".base:\n  script: [make]\nchild:\n  extends: .base\n  stage: test\n"),
+		[]byte("stages: [a, b]\njob-a:\n  stage: a\n  script: run\njob-b:\n  stage: b\n  needs: [job-a]\n  script: run\n"),
+		[]byte("*undefined_anchor"),
+		[]byte("- item1\n- item2\n"),
+		[]byte("my-job: \"just a string\"\n"),
+		[]byte("my-job:\n  stage: [build, test]\n"),
+		[]byte("# glint: ignore GL007\nlegacy:\n  only: [main]\n  script: ok\n"),
+		[]byte("workflow:\n  rules:\n    - if: '$CI_COMMIT_BRANCH == \"main\"'\n      when: always\njob:\n  script: echo ok\n"),
+		[]byte("include:\n  - local: other.yml\njob:\n  script: echo ok\n"),
+		[]byte("job:\n  script: echo ok\n  when: on_failure\n  rules:\n    - if: '$VAR =~ /^us\\//'\n"),
+		[]byte("job:\n  stage: test\n  image:\n    name: golang:1.21\n    entrypoint: ['']\n  parallel:\n    matrix:\n      - PLATFORM: [linux, darwin]\n  script: go build\n"),
+		[]byte("default:\n  retry: 2\n  timeout: 1h30m\nvariables:\n  ENV: production\nstages: [build, test, deploy]\n"),
+		[]byte("&anchor\n  script: [echo ok]\njob:\n  <<: *anchor\n  stage: build\n"),
+		[]byte("?"), // null/empty YAML key — must error, not produce an empty-named job
+	}
+	for _, s := range seeds {
+		f.Add(s)
+	}
+
+	f.Fuzz(func(t *testing.T, data []byte) {
+		p, err := ParseBytes(data)
+		if err != nil {
+			return // errors are acceptable; panics are not
+		}
+		if p == nil {
+			t.Fatal("ParseBytes returned nil pipeline with nil error")
+		}
+		for name := range p.Jobs {
+			if name == "" {
+				t.Fatal("ParseBytes produced a job with an empty name")
+			}
+		}
+	})
+}
+
+// FuzzSanitizeYAMLEscapes ensures the escape sanitizer never panics and never
+// produces output shorter than its input (it can only expand \/ to \\/).
+func FuzzSanitizeYAMLEscapes(f *testing.F) {
+	seeds := [][]byte{
+		{},
+		[]byte("stage: build"),
+		[]byte(`if: "$CI_BRANCH =~ /^us\//"`),
+		[]byte(`"pattern: /^us\//"`),
+		[]byte(`'single quoted \/ unchanged'`),
+		[]byte(`"\n\t\r"`),
+		[]byte(`"nested \"quote\" inside"`),
+		[]byte(`'it''s fine'`),
+		[]byte(`"unclosed`),
+		{'"', '\\'},      // double-quoted string ending with a lone backslash
+		{'"', '\\', '/'}, // the exact sequence being rewritten
+	}
+	for _, s := range seeds {
+		f.Add(s)
+	}
+
+	f.Fuzz(func(t *testing.T, data []byte) {
+		out := sanitizeYAMLEscapes(data)
+		if len(out) < len(data) {
+			t.Fatalf("sanitizeYAMLEscapes shrank output: input len=%d output len=%d\ninput: %q",
+				len(data), len(out), data)
+		}
+	})
+}

internal/model/parser.go

@@ -57,6 +57,9 @@ func ParseBytes(data []byte) (*Pipeline, error) {
 		keyNode := root.Content[i]
 		valNode := root.Content[i+1]
 		key := keyNode.Value
+		if key == "" {
+			return nil, fmt.Errorf("job name cannot be empty (null or missing YAML key)")
+		}
 		if ReservedKeys[key] {
 			continue
 		}

internal/model/parser_test.go

@@ -88,6 +88,12 @@ func TestParseBytes_EdgeCases(t *testing.T) {
 	if err == nil {
 		t.Error("wrong field type: expected error from ParseBytes (stage must be string)")
 	}
+
+	// Null/empty YAML key (e.g. bare "?"): job name cannot be empty.
+	_, err = ParseBytes([]byte("?"))
+	if err == nil {
+		t.Error("null key: expected error from ParseBytes (job name cannot be empty)")
+	}
 }
 
 // TestParse_ParseBytesError exercises the Parse → ParseBytes error path (line 18).

internal/model/testdata/fuzz/FuzzParseBytes/c18522695dec4f60

@@ -0,0 +1,2 @@
+go test fuzz v1
+[]byte("?")

templates/check.yml

@@ -0,0 +1,62 @@
+# glint — GitLab CI/CD Catalog component
+#
+# Validates a pipeline file with glint before the rest of the pipeline runs.
+#
+# Usage (after publishing to a GitLab instance as a Catalog component):
+#
+#   include:
+#     - component: $CI_SERVER_FQDN/k3nny/glint/check@v0.2.28
+#       inputs:
+#         stage: validate   # optional — see inputs below
+#
+# Or as a plain remote include (no Catalog required):
+#
+#   include:
+#     - remote: https://raw.githubusercontent.com/.../templates/check.yml
+#
+# Or copy this file into your repository and use a local include.
+
+spec:
+  inputs:
+    stage:
+      description: "Stage in which to run the glint validation job."
+      default: validate
+    pipeline_file:
+      description: "Path to the pipeline file to validate."
+      default: .gitlab-ci.yml
+    version:
+      description: >-
+        glint release tag to download (e.g. 'v0.2.28'). Use 'latest' to
+        always pull the newest release — not recommended for production
+        pipelines since it may break on a new release.
+      default: latest
+    allow_failure:
+      description: "Set to true to let the job fail without blocking the pipeline."
+      default: false
+    extra_args:
+      description: "Additional arguments passed to 'glint check' (e.g. '--format sarif')."
+      default: ""
+
+---
+glint:check:
+  stage: $[[ inputs.stage ]]
+  image: alpine:3.19
+  variables:
+    GLINT_VERSION: "$[[ inputs.version ]]"
+    GLINT_FILE: "$[[ inputs.pipeline_file ]]"
+    GLINT_ARGS: "$[[ inputs.extra_args ]]"
+  before_script:
+    - apk add --no-cache curl
+    - |
+      if [ "$GLINT_VERSION" = "latest" ]; then
+        GLINT_VERSION=$(curl -sf \
+          "https://git.k3nny.fr/api/v1/repos/k3nny/glint/releases?limit=1" \
+          | grep '"tag_name"' | head -1 | cut -d'"' -f4)
+      fi
+      URL="https://git.k3nny.fr/k3nny/glint/releases/download/${GLINT_VERSION}/glint-${GLINT_VERSION}-linux-amd64"
+      curl -sfL "$URL" -o /usr/local/bin/glint
+      chmod +x /usr/local/bin/glint
+      glint --version
+  script:
+    - glint check $GLINT_ARGS "$GLINT_FILE"
+  allow_failure: $[[ inputs.allow_failure ]]