feat(cli): add VS Code extension wrapping glint lsp

editors/vscode/ is a TypeScript VS Code extension that starts glint lsp
as a child process and connects to it via vscode-languageclient. The
documentSelector restricts LSP processing to **/.gitlab-ci.yml so other
YAML files are unaffected. The glint.executablePath setting controls the
binary location (default: glint on PATH). Build with task ext-compile;
package as .vsix with task ext-package. Taskfile tasks added:
ext-install, ext-compile, ext-package. Root .gitignore updated to
exclude node_modules/, out/, and *.vsix from the extension directory.

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

.gitignore

@@ -33,6 +33,11 @@ coverage.txt
 *.swo
 *~
 
+# VS Code extension build artifacts
+editors/vscode/node_modules/
+editors/vscode/out/
+editors/vscode/*.vsix
+
 # OS
 .DS_Store
 Thumbs.db

.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 +5,62 @@ 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).
 
+## [0.2.30] - 2026-06-26
+
+### Added
+
+- **VS Code extension** (`editors/vscode/`) — TypeScript extension that starts `glint lsp` as a language server and connects to it via `vscode-languageclient`. Activates on YAML files; the `documentSelector` restricts LSP processing to `**/.gitlab-ci.yml` so other YAML files are unaffected. Inline error/warning squiggles appear on every save or edit. The `glint.executablePath` setting controls the binary path (default: `glint` on `PATH`). Build: `task ext-compile`; package as `.vsix`: `task ext-package`.
+
+## [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
+
+- **Same-stage job ordering** — when jobs within the same declared GitLab stage have `needs:` relationships between each other, the pipeline graph now splits that stage into topological sub-columns: jobs with no same-stage dependencies occupy the leftmost sub-column; jobs that depend on them are placed one sub-column to the right. Sub-columns use a narrower 20 px gap (vs. the 50 px gap between stages), and the stage header spans all sub-columns. Stages with no intra-stage `needs:` are unaffected.
+
+- **Graph links rendered behind job chips** — SVG connector lines (Bézier curves in DAG mode, bus-bar stubs in classic mode) are now drawn before the job chip rectangles, so connector lines pass behind chips rather than on top of them.
+
+## [0.2.25] - 2026-06-25
+
+### Added
+
+- **`when: on_failure` visual distinction** — SVG and HTML pipeline graphs now render failure-path jobs with a red status circle (`#d9534f`), an X-mark icon, and a dashed chip border. A new `on_failure` legend entry and Mermaid `classDef` entry are included.
+
+- **Job tooltip / detail panel** — every job chip in SVG and HTML output is wrapped in a `<g data-job="…"><title>…</title><desc>…</desc>` group. SVG viewers that support `<title>` show the job name on hover; `<desc>` carries `stage`, `when`, `image`, and `needs` details. In HTML output the sidebar reads these directly from the DOM.
+
+- **Multi-job connector accuracy** — classic mode (no `needs:`) now uses a bus-bar connector: horizontal stubs from every job in stage N to a vertical rail at the midpoint, then stubs from the rail to every job in stage N+1. The previous single center-to-center line left top and bottom jobs visually disconnected.
+
+- **Skipped / blocked state colouring** — `glint graph pipeline` now accepts the same context flags as `glint check` (`--branch`, `--tag`, `--source`, `--var`, `--changes`, `--changes-from`). Jobs that evaluate to `JobSkipped` in the given context are rendered with a grey circle (`#868686`) and dimmed job name. When no context flags are given, all jobs render with their normal colours.
+
+- **Interactive HTML output** (`--format html`) — `glint graph pipeline --format html` writes a self-contained `.html` file to `--out`. The page embeds the SVG inline with mouse-wheel zoom (centred on cursor), drag-to-pan, double-click-to-reset, and a collapsible sidebar showing job details on chip click. No external dependencies; works offline.
+
+- **Mermaid pipeline output** (`--format mermaid`) — `glint graph pipeline --format mermaid` prints the existing Mermaid flowchart (`pipeline.go`) to stdout. Suitable for pasting into [mermaid.live](https://mermaid.live) or embedding in Markdown documentation.
+
+- **`imageString` helper** — internal utility that extracts the image name from a `Job.Image` field that may be a plain string or a map (`image: {name: ..., entrypoint: ...}`); used by the tooltip desc builder.
+
 ## [0.2.24] - 2026-06-25
 
 ### Added

FEATURES.md

@@ -282,8 +282,29 @@ jobs or pipeline-level findings.
 | `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 |
 
+**`glint graph pipeline --format <FORMAT>`**
+
+| Format | Effect |
+|--------|--------|
+| `svg` (default) | Write GitLab CI-style SVG/PNG to `--out` |
+| `mermaid` | Print Mermaid flowchart to stdout (paste into [mermaid.live](https://mermaid.live)) |
+| `html` | Write self-contained HTML to `--out` with mouse pan/zoom and a click-to-open job-detail sidebar |
+
+**Visual distinctions in SVG and HTML output:**
+
+- **Regular** — blue circle with checkmark
+- **Manual** — orange circle with play triangle
+- **Trigger** — purple circle with chevron
+- **Delayed** — yellow circle with clock
+- **`when: on_failure`** — red circle (`#d9534f`) with X mark; dashed chip border
+- **Skipped** (with `--branch`/`--tag`/`--source` context flags) — grey circle, dimmed job name
+
 In DAG pipelines (any job has `needs:`) the pipeline graph uses job-to-job
-Bézier connectors instead of stage-to-stage lines.
+Bézier connectors. In classic mode a bus-bar pattern (vertical rail + per-job
+stubs) accurately connects every job across adjacent stages.
+
+Each chip carries a `<title>` and `<desc>` with stage, when, image, and needs —
+shown as a tooltip in SVG viewers and as a sidebar panel in HTML output.
 
 ---
 

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-v0.2.24-blue.svg" alt="Release"></a>
+  <a href="CHANGELOG.md"><img src="https://img.shields.io/badge/release-v0.2.30-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.
@@ -20,7 +20,9 @@ A local tool to validate and lint `.gitlab-ci.yml` pipelines without needing a G
 - **Simulates context** — `--branch`, `--tag`, `--source` flags evaluate `rules:if:` and `only`/`except` to show which jobs would be active, manual, or skipped; `--context branch=main --context branch=develop` prints a multi-column comparison table across multiple contexts in one run
 - **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
+- **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.
+- **VS Code extension** — `editors/vscode/` wraps the LSP server; inline squiggles for every glint rule directly in the editor
 
 See [FEATURES.md](FEATURES.md) for the complete feature reference and lint rules table, and [ROADMAP.md](ROADMAP.md) for planned improvements.
 
@@ -32,7 +34,7 @@ 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 +54,82 @@ 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).
+
+### VS Code extension
+
+Clone this repository and load the extension from `editors/vscode/`:
+
+```bash
+cd editors/vscode
+npm install          # install dependencies (once)
+npm run compile      # compile TypeScript → out/
+```
+
+Then in VS Code: **Run → Start Debugging** (F5) — this opens an Extension Development Host with glint diagnostics active for any `.gitlab-ci.yml` you open.
+
+Make sure `glint` is on your `PATH`, or set `glint.executablePath` in VS Code settings to the full path of the binary.
+
+To package a `.vsix` for local installation:
+
+```bash
+task ext-package     # produces glint-X.Y.Z.vsix
+code --install-extension glint-X.Y.Z.vsix
+```
+
 ## Development
 
 This project uses [Task](https://taskfile.dev) as a task runner.
@@ -69,11 +141,21 @@ 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 ext-install     # install VS Code extension npm dependencies
+task ext-compile     # compile the VS Code extension TypeScript source
+task ext-package     # package the VS Code extension as a .vsix
 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
+- [x] **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
+- [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
-- ~~**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: 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 `$CI_COMMIT_BRANCH` everywhere
+- [x] **Expression evaluator: `${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
+- [x] **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
+- [x] **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
+- [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
-- ~~**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] **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
+- [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
-- ~~**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] **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
+- [x] **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
+- [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
-- ~~**Workflow rule strict evaluation**~~ — ✓ shipped v0.2.14; unparseable `if:` skips the rule instead of matching everything; prevents wrong variables being injected
+- [x] **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
+- [x] **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
+- [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
-- ~~**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] **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] **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
+- [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
-- ~~**`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] **`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
+- [x] **`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
+- [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
-- ~~**`timeout` format validation (GL036)**~~ — ✓ shipped v0.2.16; validates job-level and `default.timeout` against recognised GitLab CI duration strings
+- [x] **`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
+- [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
-- ~~**`pages:publish` + `artifacts.paths` consistency (GL039)**~~ — ✓ shipped v0.2.16; warns when the publish directory is missing from `artifacts.paths`
+- [x] **`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:`
+- [x] **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
+- [x] **`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
+- [x] **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] **`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
+- [x] **`include: local:` full resolution** — shipped 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
+- [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
-- ~~**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] **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`
+- [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`
-- ~~**`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: 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)
+- [x] **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
+- [x] **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
+- [x] **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] **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
 
 ---
 
@@ -69,53 +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
+- [x] **Terminal job tree** — shipped 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
+- [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
-- **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
+- [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
-- **Job tooltip / detail panel** — embed a hidden `<title>` and `<desc>` per chip so SVG viewers show `stage`, `when`, `image`, and `needs` on hover
+- [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
-- **`when: on_failure` visual distinction** — dashed border or distinct icon for failure-path jobs
+- [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
-- **Blocked / skipped state colouring** — grey out jobs that are statically unreachable given known `rules:` conditions
+- [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
-- **Interactive HTML output** — self-contained `.html` file with pan/zoom and a job-detail sidebar; no external dependencies
+- [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
-- **Mermaid pipeline output** — keep `pipeline.go` but wire it up through `--graph pipeline --format mermaid` for users who want to paste into mermaid.live
+- [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.
+- [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
-~~**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)
-**Remaining improvements**
+- [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)
-
-- ~~**`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
+- [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
-- **GitHub Actions action** — `uses: k3nny/glint@v1` wrapper for repositories that mirror or manage GitLab pipelines from GitHub
+- [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`
-- **Pre-commit hook** — entry for [pre-commit](https://pre-commit.com) so `glint` runs automatically on `git commit` when `.gitlab-ci.yml` changes
+- [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
-- **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
+- [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`
+- [x] **VS Code extension** — shipped v0.2.30; `editors/vscode/` TypeScript extension wraps `glint lsp` via `vscode-languageclient`; activates on YAML files and restricts LSP processing to `**/.gitlab-ci.yml`; configurable binary path via `glint.executablePath`; build with `task ext-compile`, package with `task ext-package`
 
 ---
 
-## 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
+- [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
-- ~~**Inline suppression comments**~~ — ✓ shipped v0.2.19; `# glint: ignore GL007` before a job definition; comma/space-separated rules; `# glint: ignore all` wildcard
+- [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
+- [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
-- ~~**`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] **`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)
+- [x] **Semantic versioning and first release** — shipped 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`
+- [x] **Subcommand CLI** — shipped 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
+- [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
-- **Fuzz testing** — add a `go test -fuzz` target for the YAML parser to harden it against malformed input
+- [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 +175,39 @@ 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
+
+  ext-install:
+    desc: Install VS Code extension npm dependencies (run once after checkout)
+    dir: editors/vscode
+    cmd: npm install
+
+  ext-compile:
+    desc: Compile the VS Code extension TypeScript source
+    dir: editors/vscode
+    cmd: npm run compile
+
+  ext-package:
+    desc: Package the VS Code extension into a .vsix file
+    dir: editors/vscode
+    deps: [ext-compile]
+    cmd: npm run package
+
   clean:
     desc: Remove build artifacts
     cmd: rm -f {{.BINARY}} {{.BINARY}}-*.exe {{.BINARY}}-*-linux-amd64

USAGE.md

@@ -206,7 +206,16 @@ glint graph includes .gitlab-ci.yml > includes.mmd
 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
+# Pipeline graph with skipped-job colouring (grey out context-unreachable jobs)
+glint graph pipeline --branch main .gitlab-ci.yml
+
+# Interactive HTML with pan/zoom and job-detail sidebar
+glint graph pipeline --format html .gitlab-ci.yml
+
+# Mermaid flowchart of the pipeline to stdout
+glint graph pipeline --format mermaid .gitlab-ci.yml
+
+# Mermaid includes graph to stdout + pipeline SVG file path to stderr
 glint graph all .gitlab-ci.yml > includes.mmd
 
 # Custom output directory
@@ -224,6 +233,28 @@ include type: orange (main file), purple (project), green (component), blue
 
 **Pipeline graph** — GitLab CI-style SVG rendered to a timestamped file.
 Converted to PNG when `rsvg-convert`, `inkscape`, or `magick` is available.
+
+**Pipeline graph formats** (`--format`):
+
+| Flag | Output |
+|------|--------|
+| `svg` (default) | Write SVG/PNG to `--out` |
+| `html` | Write self-contained HTML to `--out` — inline SVG with mouse pan/zoom, drag, and a job-detail sidebar that opens on chip click |
+| `mermaid` | Print Mermaid flowchart to stdout |
+
+**Visual chip styles:**
+
+| Type | Colour | Icon | Border |
+|------|--------|------|--------|
+| regular | blue `#1f75cb` | checkmark | solid |
+| manual | orange `#fc6d26` | play triangle | solid |
+| trigger | purple `#6b4fbb` | chevron | solid |
+| delayed | yellow `#fca326` | clock | solid |
+| on_failure | red `#d9534f` | X mark | dashed |
+| skipped (context) | grey `#868686` | none | solid |
+
+Pass context flags (`--branch`, `--tag`, `--source`, `--var`) to grey out jobs
+that would be skipped in the given pipeline event.
 DAG mode (Bézier arrows between jobs) activates automatically when any job has
 a `needs:` list; classic mode uses stage-column connectors otherwise.
 

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)
@@ -445,7 +448,8 @@ func cmdGraph(args []string) {
 	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)")
+	out := fs.String("out", "glint-out", "output directory for rendered graph files (pipeline mode)")
+	format := fs.String("format", "svg", "pipeline output format: svg, mermaid, or html")
 	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.
@@ -462,6 +466,15 @@ Options:
           Output directory for rendered graph files.
           Used by the pipeline and all modes only. [default: glint-out]
 
+      --format <FORMAT>
+          Output format for pipeline mode: svg (default), mermaid, or html.
+          svg:     write a GitLab CI-style SVG/PNG to --out (converted to PNG
+                   when rsvg-convert, inkscape, or magick is available).
+          mermaid: print a Mermaid flowchart to stdout (paste into mermaid.live).
+          html:    write a self-contained HTML file with pan/zoom and a
+                   job-detail sidebar to --out.
+          [default: svg] [possible values: svg, mermaid, html]
+
       --token <TOKEN>
           GitLab personal access token. Used to fetch remote project: includes
           when building the include dependency graph.
@@ -518,6 +531,8 @@ Examples:
   glint graph includes .gitlab-ci.yml > includes.mmd
   glint graph pipeline .gitlab-ci.yml
   glint graph pipeline --out /tmp/graphs .gitlab-ci.yml
+  glint graph pipeline --format mermaid .gitlab-ci.yml
+  glint graph pipeline --format html .gitlab-ci.yml
   glint graph all .gitlab-ci.yml > includes.mmd
 `)
 	}
@@ -602,16 +617,29 @@ Examples:
 	case "includes":
 		fmt.Print(graph.Includes(path, p.Include, cfg))
 	case "pipeline":
-		outPath, err := graph.RenderPipeline(p, *out)
+		switch *format {
+		case "mermaid":
+			fmt.Print(graph.Pipeline(p))
+		case "html":
+			outPath, err := graph.RenderHTML(p, *out, ctx)
 			if err != nil {
 				fmt.Fprintf(os.Stderr, "error: rendering pipeline graph: %v\n", err)
 				exit(2)
 				return
 			}
 			fmt.Println(outPath)
+		default: // "svg"
+			outPath, err := graph.RenderPipeline(p, *out, ctx)
+			if err != nil {
+				fmt.Fprintf(os.Stderr, "error: rendering pipeline graph: %v\n", err)
+				exit(2)
+				return
+			}
+			fmt.Println(outPath)
+		}
 	case "all":
 		fmt.Print(graph.Includes(path, p.Include, cfg))
-		outPath, err := graph.RenderPipeline(p, *out)
+		outPath, err := graph.RenderPipeline(p, *out, ctx)
 		if err != nil {
 			fmt.Fprintf(os.Stderr, "error: rendering pipeline graph: %v\n", err)
 			exit(2)

editors/vscode/.gitignore

@@ -0,0 +1,3 @@
+node_modules/
+out/
+*.vsix

editors/vscode/.vscodeignore

@@ -0,0 +1,8 @@
+src/**
+tsconfig.json
+.gitignore
+node_modules/**
+!node_modules/vscode-languageclient/**
+!node_modules/vscode-languageserver-protocol/**
+!node_modules/vscode-languageserver-types/**
+!node_modules/vscode-jsonrpc/**

editors/vscode/package.json

@@ -0,0 +1,56 @@
+{
+  "name": "glint",
+  "displayName": "glint — GitLab CI Linter",
+  "description": "Inline diagnostics for .gitlab-ci.yml pipelines powered by the glint language server",
+  "version": "0.2.29",
+  "publisher": "k3nny",
+  "license": "Apache-2.0",
+  "repository": {
+    "type": "git",
+    "url": "https://git.k3nny.fr/k3nny/glint"
+  },
+  "engines": {
+    "vscode": "^1.82.0"
+  },
+  "categories": [
+    "Linters"
+  ],
+  "keywords": [
+    "gitlab",
+    "ci",
+    "yaml",
+    "lint",
+    "pipeline"
+  ],
+  "activationEvents": [
+    "onLanguage:yaml"
+  ],
+  "main": "./out/extension.js",
+  "contributes": {
+    "configuration": {
+      "type": "object",
+      "title": "glint",
+      "properties": {
+        "glint.executablePath": {
+          "type": "string",
+          "default": "glint",
+          "markdownDescription": "Path to the `glint` binary. Leave as `glint` if it is on your `PATH`, or set an absolute path (e.g. `/usr/local/bin/glint`)."
+        }
+      }
+    }
+  },
+  "scripts": {
+    "compile": "tsc -p ./",
+    "watch": "tsc --watch -p ./",
+    "package": "vsce package"
+  },
+  "dependencies": {
+    "vscode-languageclient": "^9.0.1"
+  },
+  "devDependencies": {
+    "@types/node": "^20",
+    "@types/vscode": "^1.82.0",
+    "@vscode/vsce": "^2.22.0",
+    "typescript": "^5.3.0"
+  }
+}

editors/vscode/src/extension.ts

@@ -0,0 +1,41 @@
+import * as vscode from 'vscode';
+import {
+  LanguageClient,
+  LanguageClientOptions,
+  ServerOptions,
+  TransportKind,
+} from 'vscode-languageclient/node';
+
+let client: LanguageClient | undefined;
+
+export function activate(context: vscode.ExtensionContext): void {
+  const cfg = vscode.workspace.getConfiguration('glint');
+  const glintPath = cfg.get<string>('executablePath') || 'glint';
+
+  const serverOptions: ServerOptions = {
+    command: glintPath,
+    args: ['lsp'],
+    transport: TransportKind.stdio,
+  };
+
+  const clientOptions: LanguageClientOptions = {
+    // Only process .gitlab-ci.yml files, not all YAML.
+    documentSelector: [
+      { scheme: 'file', language: 'yaml', pattern: '**/.gitlab-ci.yml' },
+    ],
+  };
+
+  client = new LanguageClient(
+    'glint',
+    'glint — GitLab CI Linter',
+    serverOptions,
+    clientOptions,
+  );
+
+  client.start();
+  context.subscriptions.push(client);
+}
+
+export async function deactivate(): Promise<void> {
+  await client?.stop();
+}

editors/vscode/tsconfig.json

@@ -0,0 +1,15 @@
+{
+  "compilerOptions": {
+    "module": "commonjs",
+    "target": "ES2020",
+    "lib": ["ES2020"],
+    "outDir": "out",
+    "rootDir": "src",
+    "strict": true,
+    "sourceMap": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true
+  },
+  "include": ["src"],
+  "exclude": ["node_modules", "out"]
+}

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/mod v0.35.0 // indirect
-	golang.org/x/sync v0.19.0 // indirect
+	golang.org/x/sync v0.20.0 // indirect
-	golang.org/x/tools v0.40.1-0.20260108161641-ca281cf95054 // indirect
+	golang.org/x/tools v0.44.1-0.20260420230617-19499e7caabc // indirect
-	gopkg.in/yaml.v3 v3.0.1 // indirect
+	honnef.co/go/tools v0.8.0-rc.1 // indirect
-	honnef.co/go/tools v0.7.0 // 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 v0.35.0 h1:Ww1D637e6Pg+Zb2KrWfHQUnH2dQRLBQyAtpr/haaJeM=
-golang.org/x/mod v0.31.0/go.mod h1:43JraMp9cGx1Rx3AqioxrbrhNsLl2l/iNAvuBkrezpg=
+golang.org/x/mod v0.35.0/go.mod h1:+GwiRhIInF8wPm+4AoT6L0FA1QWAad3OMdTRx4tFYlU=
-golang.org/x/sync v0.19.0 h1:vV+1eWNmZ5geRlYjzm2adRgW2/mcpevXNg50YZtPCE4=
+golang.org/x/sync v0.20.0 h1:e0PTpb7pjO8GAtTs2dQ6jYa5BWYlMuX047Dco/pItO4=
-golang.org/x/sync v0.19.0/go.mod h1:9KTHXmSnoGruLpwFjVSX0lNNA75CykiMECbovNTZqGI=
+golang.org/x/sync v0.20.0/go.mod h1:9xrNwdLfx4jkKbNva9FpL6vEN7evnE43NNNJQ2LF3+0=
-golang.org/x/tools v0.40.1-0.20260108161641-ca281cf95054 h1:CHVDrNHx9ZoOrNN9kKWYIbT5Rj+WF2rlwPkhbQQ5V4U=
+golang.org/x/tools v0.44.1-0.20260420230617-19499e7caabc h1:vSv/HN1q9eoPD7lMyJYVJ/GPYnqtqu6adMxUmrxOB78=
-golang.org/x/tools v0.40.1-0.20260108161641-ca281cf95054/go.mod h1:Ik/tzLRlbscWpqqMRjyWYDisX8bG13FrdXp3o4Sr9lc=
+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 v0.8.0-rc.1 h1:wqMm2kjcEXMOr+6yau+pdKqJKe6l2N1aKPkpini+Kzk=
-honnef.co/go/tools v0.7.0/go.mod h1:pm29oPxeP3P82ISxZDgIYeOaf9ta6Pi0EWvCFoLG2vc=
+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/graph/pipeline.go

@@ -27,6 +27,7 @@ func Pipeline(p *model.Pipeline) string {
 	w("    classDef manual fill:#fc6d26,stroke:#e56b1f,color:#fff")
 	w("    classDef trigger fill:#6b4fbb,stroke:#5a3fa0,color:#fff")
 	w("    classDef delayed fill:#fca326,stroke:#d98a1e,color:#333")
+	w("    classDef on_failure fill:#d9534f,stroke:#c0392b,color:#fff")
 	w("")
 
 	// Collect visible (non-template) job names; sort for stable output.
@@ -149,6 +150,8 @@ func jobClass(job model.Job) string {
 		return "manual"
 	case "delayed":
 		return "delayed"
+	case "on_failure":
+		return "on_failure"
 	}
 	return "regular"
 }

internal/graph/pipeline_test.go

@@ -105,10 +105,23 @@ func TestSanitizeID(t *testing.T) {
 func TestJobClass(t *testing.T) {
 	if jobClass(model.Job{When: "manual"}) != "manual" { t.Error("manual") }
 	if jobClass(model.Job{When: "delayed"}) != "delayed" { t.Error("delayed") }
+	if jobClass(model.Job{When: "on_failure"}) != "on_failure" { t.Error("on_failure") }
 	if jobClass(model.Job{Trigger: "x"}) != "trigger" { t.Error("trigger") }
 	if jobClass(model.Job{}) != "regular" { t.Error("regular") }
 }
 
+func TestPipeline_OnFailureClass(t *testing.T) {
+	p := &model.Pipeline{
+		Stages: []string{"cleanup"},
+		Jobs: map[string]model.Job{
+			"cleanup-job": {Name: "cleanup-job", Stage: "cleanup", When: "on_failure"},
+		},
+	}
+	out := Pipeline(p)
+	if !strings.Contains(out, "on_failure") { t.Error("expected on_failure class") }
+	if !strings.Contains(out, "#d9534f") { t.Error("expected on_failure color in classDef") }
+}
+
 // ── needsJobName ──────────────────────────────────────────────────────────────
 
 func TestNeedsJobName(t *testing.T) {

internal/graph/render.go

@@ -10,6 +10,7 @@ import (
 	"strings"
 	"time"
 
+	"git.k3nny.fr/glint/internal/cicontext"
 	"git.k3nny.fr/glint/internal/model"
 )
 
@@ -18,26 +19,129 @@ const (
 	chipW       = 178 // job chip width
 	chipH       = 34  // job chip height
 	chipGap     = 6   // vertical gap between chips in a column
-	iconCX    = 14  // status circle: x offset from chip left edge to circle centre
+	iconCX      = 14  // status circle: x offset from chip left edge to centre
 	iconR       = 7   // status circle radius (14 px diameter)
 	textLeft    = 27  // job name text: x offset from chip left edge
 	labelH      = 30  // stage-name label area height (text + bottom gap)
 	topPad      = 40  // outer top padding
 	sidePad     = 40  // outer left / right padding
 	stageGap    = 50  // horizontal gap between stage columns (connector space)
+	subStageGap = 20  // horizontal gap between sub-columns within the same stage
 	botPad      = 48  // outer bottom padding (legend lives here)
 )
 
 type svgPt struct{ x, y int }
 
+// column represents one vertical stack of job chips in the SVG.
+// A declared GitLab stage maps to one column unless jobs within it have
+// same-stage needs:, in which case it splits into topological sub-columns.
+type column struct {
+	stage string   // declared GitLab stage name
+	jobs  []string // job names in this column, topologically ordered
+}
+
+// computeColumns assigns jobs to SVG columns.
+// When jobs within the same declared stage have needs: relationships between
+// each other, the stage is split into topological sub-columns so that
+// depended-upon jobs appear to the left of the jobs that depend on them.
+func computeColumns(stages []string, byStage map[string][]string, jobs map[string]model.Job) []column {
+	var cols []column
+	for _, stage := range stages {
+		stageJobs := byStage[stage]
+		sort.Strings(stageJobs)
+		if len(stageJobs) == 0 {
+			continue
+		}
+
+		// Index same-stage membership.
+		stageSet := make(map[string]bool, len(stageJobs))
+		for _, j := range stageJobs {
+			stageSet[j] = true
+		}
+
+		// Check whether any job has a same-stage need.
+		hasIntraNeeds := false
+		outer:
+		for _, j := range stageJobs {
+			for _, need := range jobs[j].Needs {
+				if dep := needsJobName(need); dep != "" && stageSet[dep] {
+					hasIntraNeeds = true
+					break outer
+				}
+			}
+		}
+
+		if !hasIntraNeeds {
+			cols = append(cols, column{stage: stage, jobs: stageJobs})
+			continue
+		}
+
+		// Compute topological depth within the stage.
+		depth := make(map[string]int, len(stageJobs))
+		for _, j := range stageJobs {
+			depth[j] = -1
+		}
+		inProgress := make(map[string]bool, len(stageJobs))
+		var computeDepth func(j string) int
+		computeDepth = func(j string) int {
+			if depth[j] >= 0 {
+				return depth[j]
+			}
+			if inProgress[j] {
+				return 0 // cycle guard (cycles already rejected by GL029)
+			}
+			inProgress[j] = true
+			maxDep := -1
+			for _, need := range jobs[j].Needs {
+				dep := needsJobName(need)
+				if dep == "" || !stageSet[dep] {
+					continue
+				}
+				d := computeDepth(dep)
+				if d > maxDep {
+					maxDep = d
+				}
+			}
+			depth[j] = maxDep + 1
+			return depth[j]
+		}
+		for _, j := range stageJobs {
+			if depth[j] < 0 {
+				computeDepth(j)
+			}
+		}
+
+		// One sub-column per topological depth level.
+		maxDepth := 0
+		for _, j := range stageJobs {
+			if depth[j] > maxDepth {
+				maxDepth = depth[j]
+			}
+		}
+		for l := 0; l <= maxDepth; l++ {
+			var levelJobs []string
+			for _, j := range stageJobs {
+				if depth[j] == l {
+					levelJobs = append(levelJobs, j)
+				}
+			}
+			if len(levelJobs) > 0 {
+				sort.Strings(levelJobs)
+				cols = append(cols, column{stage: stage, jobs: levelJobs})
+			}
+		}
+	}
+	return cols
+}
+
 // RenderPipeline writes a PNG (or SVG fallback) file with a GitLab CI-style
 // pipeline layout and returns the path to the generated file.
-func RenderPipeline(p *model.Pipeline, outDir string) (string, error) {
+func RenderPipeline(p *model.Pipeline, outDir string, ctx *cicontext.Context) (string, error) {
 	if err := os.MkdirAll(outDir, 0o755); err != nil {
 		return "", fmt.Errorf("creating output directory %s: %w", outDir, err)
 	}
 
-	svg := pipelineSVG(p)
+	svg := pipelineSVG(p, ctx)
 
 	ts := time.Now().Format("20060102-150405")
 	svgPath := filepath.Join(outDir, "pipeline-"+ts+".svg")
@@ -53,6 +157,24 @@ func RenderPipeline(p *model.Pipeline, outDir string) (string, error) {
 	return svgPath, nil
 }
 
+// RenderHTML writes a self-contained HTML file with the pipeline graph embedded
+// inline with pan/zoom and a job-detail sidebar, then returns the output path.
+func RenderHTML(p *model.Pipeline, outDir string, ctx *cicontext.Context) (string, error) {
+	if err := os.MkdirAll(outDir, 0o755); err != nil {
+		return "", fmt.Errorf("creating output directory %s: %w", outDir, err)
+	}
+
+	svg := pipelineSVG(p, ctx)
+	html := htmlPage(svg)
+
+	ts := time.Now().Format("20060102-150405")
+	htmlPath := filepath.Join(outDir, "pipeline-"+ts+".html")
+	if err := os.WriteFile(htmlPath, []byte(html), 0o644); err != nil {
+		return "", fmt.Errorf("writing HTML: %w", err)
+	}
+	return htmlPath, nil
+}
+
 // convertToPNG tries rsvg-convert, Inkscape, magick, and convert (not on Windows).
 func convertToPNG(svgPath, pngPath string) bool {
 	candidates := [][]string{
@@ -75,7 +197,7 @@ func convertToPNG(svgPath, pngPath string) bool {
 	return false
 }
 
-func pipelineSVG(p *model.Pipeline) string {
+func pipelineSVG(p *model.Pipeline, ctx *cicontext.Context) string {
 	// Collect visible (non-template) job names in sorted order.
 	var visible []string
 	for name := range p.Jobs {
@@ -89,6 +211,16 @@ func pipelineSVG(p *model.Pipeline) string {
 		return svgEmpty()
 	}
 
+	// Precompute which jobs are skipped in the given context.
+	skippedJobs := make(map[string]bool)
+	if ctx != nil {
+		for _, name := range visible {
+			if cicontext.EvalJob(p.Jobs[name], ctx) == cicontext.JobSkipped {
+				skippedJobs[name] = true
+			}
+		}
+	}
+
 	// Group by stage; fall back to "test" (GitLab default) when stage is unset.
 	byStage := make(map[string][]string)
 	for _, name := range visible {
@@ -119,32 +251,42 @@ func pipelineSVG(p *model.Pipeline) string {
 		}
 	}
 
-	// Compute per-stage column heights and job anchor points for connectors.
+	// ── Column layout ─────────────────────────────────────────────────────────
-	colH := make([]int, len(stages))   // height of the chip stack (no label)
+	// Split stages into sub-columns when intra-stage needs exist.
-	colCtY := make([]int, len(stages)) // y centre of the chip stack
+	cols := computeColumns(stages, byStage, p.Jobs)
+
+	// X position of each column's left edge.
+	colX := make([]int, len(cols))
+	if len(cols) > 0 {
+		colX[0] = sidePad
+		for i := 1; i < len(cols); i++ {
+			gap := stageGap
+			if cols[i].stage == cols[i-1].stage {
+				gap = subStageGap
+			}
+			colX[i] = colX[i-1] + chipW + gap
+		}
+	}
+
+	// Compute SVG dimensions and per-job connector anchor points.
 	maxColH := 0
 	rightMid := make(map[string]svgPt)
 	leftMid := make(map[string]svgPt)
 
-	for i, stage := range stages {
+	for ci, col := range cols {
-		jobs := byStage[stage]
+		n := len(col.jobs)
-		sort.Strings(jobs)
-		n := len(jobs)
 		h := n*chipH + max(0, n-1)*chipGap
-		colH[i] = h
 		if h > maxColH {
 			maxColH = h
 		}
-		cx := sidePad + i*(chipW+stageGap)
+		for j, name := range col.jobs {
-		for j, name := range jobs {
 			chy := topPad + labelH + j*(chipH+chipGap)
-			rightMid[name] = svgPt{cx + chipW, chy + chipH/2}
+			rightMid[name] = svgPt{colX[ci] + chipW, chy + chipH/2}
-			leftMid[name] = svgPt{cx, chy + chipH/2}
+			leftMid[name] = svgPt{colX[ci], chy + chipH/2}
 		}
-		colCtY[i] = topPad + labelH + h/2
 	}
 
-	svgW := sidePad*2 + len(stages)*chipW + max(0, len(stages)-1)*stageGap
+	svgW := colX[len(cols)-1] + chipW + sidePad
 	svgH := topPad + labelH + maxColH + botPad
 
 	// DAG mode: any visible job with a needs: list triggers job-to-job arrows.
@@ -174,49 +316,35 @@ func pipelineSVG(p *model.Pipeline) string {
 	// White page background.
 	wf(`  <rect width="%d" height="%d" fill="#ffffff"/>`, svgW, svgH)
 
-	// ── Stage columns ─────────────────────────────────────────────────────────
+	// ── Stage headers ─────────────────────────────────────────────────────────
-	for i, stage := range stages {
+	// Each declared stage may span multiple sub-columns; draw one header per stage.
-		cx := sidePad + i*(chipW+stageGap)
+	drawnHeader := make(map[string]bool)
-		jobs := byStage[stage]
+	for ci, col := range cols {
-		sort.Strings(jobs)
+		if drawnHeader[col.stage] {
+			continue
+		}
+		// Span all sub-columns that belong to this stage.
+		x1 := colX[ci]
+		x2 := colX[ci] + chipW
+		for j := ci + 1; j < len(cols) && cols[j].stage == col.stage; j++ {
+			x2 = colX[j] + chipW
+		}
+		centerX := (x1 + x2) / 2
 
-		// Stage name – small, gray, uppercase, centered above the chip stack.
+		// Stage name – small, gray, uppercase.
 		wf(`  <text x="%d" y="%d" text-anchor="middle" `+
 			`font-family="'GitLab Sans','Segoe UI',-apple-system,BlinkMacSystemFont,sans-serif" `+
 			`font-size="11" font-weight="600" letter-spacing="0.8" fill="#868686">%s</text>`,
-			cx+chipW/2, topPad+13, svgEsc(strings.ToUpper(stage)))
+			centerX, topPad+13, svgEsc(strings.ToUpper(col.stage)))
 
-		// Subtle separator line below stage name.
+		// Separator line spanning all sub-columns.
 		wf(`  <line x1="%d" y1="%d" x2="%d" y2="%d" stroke="#eaeaea" stroke-width="1"/>`,
-			cx, topPad+21, cx+chipW, topPad+21)
+			x1, topPad+21, x2, topPad+21)
 
-		// Job chips.
+		drawnHeader[col.stage] = true
-		for j, name := range jobs {
-			job := p.Jobs[name]
-			chy := topPad + labelH + j*(chipH+chipGap)
-			color := chipColor(job)
-
-			// Chip card (white, rounded, subtle border + shadow).
-			wf(`  <rect x="%d" y="%d" width="%d" height="%d" rx="4" `+
-				`fill="#ffffff" stroke="#dde1e7" stroke-width="1" filter="url(#chip-shadow)"/>`,
-				cx, chy, chipW, chipH)
-
-			// Colored status indicator circle.
-			wf(`  <circle cx="%d" cy="%d" r="%d" fill="%s"/>`,
-				cx+iconCX, chy+chipH/2, iconR, color)
-
-			// Icon symbol inside the circle.
-			drawChipIcon(&sb, job, cx+iconCX, chy+chipH/2)
-
-			// Job name text.
-			wf(`  <text x="%d" y="%d" dominant-baseline="middle" `+
-				`font-family="'GitLab Sans','Segoe UI',-apple-system,BlinkMacSystemFont,sans-serif" `+
-				`font-size="13" fill="#303030">%s</text>`,
-				cx+textLeft, chy+chipH/2, svgEsc(svgTrunc(name, 20)))
-		}
 	}
 
-	// ── Connectors ────────────────────────────────────────────────────────────
+	// ── Connectors (drawn before chips so they appear behind job blocks) ───────
 	const connStroke = "#dbdbdb"
 
 	if dagMode {
@@ -241,27 +369,123 @@ func pipelineSVG(p *model.Pipeline) string {
 			}
 		}
 	} else {
-		// Classic: one connector per adjacent stage pair.
+		// Classic: bus-bar connectors between adjacent stage columns.
-		for i := 0; i < len(stages)-1; i++ {
+		// Every job in stage[i] fans to a vertical bus at the midpoint gap,
-			x1 := sidePad + i*(chipW+stageGap) + chipW
+		// then fans out to every job in stage[i+1].
-			x2 := sidePad + (i+1)*(chipW+stageGap)
+		for ci := 0; ci < len(cols)-1; ci++ {
-			y1 := colCtY[i]
+			x1 := colX[ci] + chipW    // right edge of current column
-			y2 := colCtY[i+1]
+			x2 := colX[ci+1]          // left edge of next column
 			midX := (x1 + x2) / 2
 
-			if y1 == y2 {
+			srcJobs := cols[ci].jobs
-				// Straight horizontal line.
+			dstJobs := cols[ci+1].jobs
-				wf(`  <line x1="%d" y1="%d" x2="%d" y2="%d" stroke="%s" stroke-width="2"/>`,
+
-					x1, y1, x2-7, y2, connStroke)
+			// Collect all Y midpoints to span the vertical bus bar.
-			} else {
+			var allYs []int
-				// L-shaped elbow: right → vertical → right.
+			srcY := make([]int, len(srcJobs))
-				wf(`  <polyline points="%d,%d %d,%d %d,%d %d,%d" `+
+			dstY := make([]int, len(dstJobs))
-					`stroke="%s" stroke-width="2" fill="none" stroke-linejoin="round"/>`,
+			for j, name := range srcJobs {
-					x1, y1, midX, y1, midX, y2, x2-7, y2, connStroke)
+				srcY[j] = rightMid[name].y
+				allYs = append(allYs, srcY[j])
 			}
-			// Arrowhead at the destination.
+			for j, name := range dstJobs {
+				dstY[j] = leftMid[name].y
+				allYs = append(allYs, dstY[j])
+			}
+			sort.Ints(allYs)
+			busMinY, busMaxY := allYs[0], allYs[len(allYs)-1]
+
+			// Vertical bus bar at midX (only when there are multiple Y levels).
+			if busMinY < busMaxY {
+				wf(`  <line x1="%d" y1="%d" x2="%d" y2="%d" stroke="%s" stroke-width="2"/>`,
+					midX, busMinY, midX, busMaxY, connStroke)
+			}
+
+			// Horizontal stubs from each source job to the bus.
+			for _, y := range srcY {
+				wf(`  <line x1="%d" y1="%d" x2="%d" y2="%d" stroke="%s" stroke-width="2"/>`,
+					x1, y, midX, y, connStroke)
+			}
+
+			// Horizontal stubs from bus to each destination job, with arrowhead.
+			for _, y := range dstY {
+				wf(`  <line x1="%d" y1="%d" x2="%d" y2="%d" stroke="%s" stroke-width="2"/>`,
+					midX, y, x2-7, y, connStroke)
 				wf(`  <polygon points="%d,%d %d,%d %d,%d" fill="%s"/>`,
-				x2-7, y2-4, x2, y2, x2-7, y2+4, connStroke)
+					x2-7, y-4, x2, y, x2-7, y+4, connStroke)
+			}
+		}
+	}
+
+	// ── Job chips (drawn after connectors so they appear on top) ─────────────
+	for ci, col := range cols {
+		for j, name := range col.jobs {
+			job := p.Jobs[name]
+			chy := topPad + labelH + j*(chipH+chipGap)
+			isSkipped := skippedJobs[name]
+			cx := colX[ci]
+
+			// Build <desc> content: shown in the HTML sidebar and SVG viewer tooltips.
+			desc := "stage: " + col.stage
+			if job.When != "" {
+				desc += "\nwhen: " + job.When
+			}
+			if img := imageString(job.Image); img != "" {
+				desc += "\nimage: " + img
+			}
+			var needNames []string
+			for _, n := range job.Needs {
+				if s := needsJobName(n); s != "" {
+					needNames = append(needNames, s)
+				}
+			}
+			if len(needNames) > 0 {
+				desc += "\nneeds: " + strings.Join(needNames, ", ")
+			}
+			if isSkipped {
+				desc += "\nstate: skipped"
+			}
+
+			// data-job attribute enables JS click detection in the HTML output.
+			wf(`  <g data-job="%s">`, svgEsc(name))
+			wf(`    <title>%s</title>`, svgEsc(name))
+			wf(`    <desc>%s</desc>`, svgEsc(desc))
+
+			color := chipColor(job)
+			if isSkipped {
+				color = "#868686"
+			}
+
+			// Chip card (white, rounded, subtle border + shadow).
+			// on_failure jobs get a dashed border to signal the failure path.
+			dashAttr := ""
+			if !isSkipped && job.When == "on_failure" {
+				dashAttr = ` stroke-dasharray="4,3"`
+			}
+			wf(`    <rect x="%d" y="%d" width="%d" height="%d" rx="4" `+
+				`fill="#ffffff" stroke="#dde1e7" stroke-width="1"%s filter="url(#chip-shadow)"/>`,
+				cx, chy, chipW, chipH, dashAttr)
+
+			// Colored status indicator circle.
+			wf(`    <circle cx="%d" cy="%d" r="%d" fill="%s"/>`,
+				cx+iconCX, chy+chipH/2, iconR, color)
+
+			// Icon inside the circle (omitted for skipped — grey circle speaks for itself).
+			if !isSkipped {
+				drawChipIcon(&sb, job, cx+iconCX, chy+chipH/2)
+			}
+
+			// Job name text — dimmed for skipped jobs.
+			textColor := "#303030"
+			if isSkipped {
+				textColor = "#868686"
+			}
+			wf(`    <text x="%d" y="%d" dominant-baseline="middle" `+
+				`font-family="'GitLab Sans','Segoe UI',-apple-system,BlinkMacSystemFont,sans-serif" `+
+				`font-size="13" fill="%s">%s</text>`,
+				cx+textLeft, chy+chipH/2, textColor, svgEsc(svgTrunc(name, 20)))
+
+			wf(`  </g>`)
 		}
 	}
 
@@ -271,6 +495,7 @@ func pipelineSVG(p *model.Pipeline) string {
 		{"#fc6d26", "manual"},
 		{"#6b4fbb", "trigger"},
 		{"#fca326", "delayed"},
+		{"#d9534f", "on_failure"},
 	}
 	const legendItemW = 82
 	legendY := topPad + labelH + maxColH + botPad/2
@@ -304,14 +529,20 @@ func drawChipIcon(sb *strings.Builder, job model.Job, cx, cy int) {
 		fmt.Fprintf(sb, "    <polygon points=\"%d,%d %d,%d %d,%d\" fill=\"#fff\"/>\n",
 			cx-3, cy-4, cx+5, cy, cx-3, cy+4)
 	case "delayed":
-		// Clock hands: vertical + horizontal.
+		// Clock: circle + hands.
 		fmt.Fprintf(sb, "    <circle cx=\"%d\" cy=\"%d\" r=\"5\" stroke=\"#fff\" stroke-width=\"1.2\" fill=\"none\"/>\n", cx, cy)
 		fmt.Fprintf(sb, "    <line x1=\"%d\" y1=\"%d\" x2=\"%d\" y2=\"%d\" stroke=\"#fff\" stroke-width=\"1.2\" stroke-linecap=\"round\"/>\n",
 			cx, cy, cx, cy-3)
 		fmt.Fprintf(sb, "    <line x1=\"%d\" y1=\"%d\" x2=\"%d\" y2=\"%d\" stroke=\"#fff\" stroke-width=\"1.2\" stroke-linecap=\"round\"/>\n",
 			cx, cy, cx+2, cy+1)
+	case "on_failure":
+		// X mark for failure-path jobs.
+		fmt.Fprintf(sb, "    <line x1=\"%d\" y1=\"%d\" x2=\"%d\" y2=\"%d\" stroke=\"#fff\" stroke-width=\"1.5\" stroke-linecap=\"round\"/>\n",
+			cx-3, cy-3, cx+3, cy+3)
+		fmt.Fprintf(sb, "    <line x1=\"%d\" y1=\"%d\" x2=\"%d\" y2=\"%d\" stroke=\"#fff\" stroke-width=\"1.5\" stroke-linecap=\"round\"/>\n",
+			cx+3, cy-3, cx-3, cy+3)
 	default:
-		// Regular job: small white checkmark outline.
+		// Regular job: small white checkmark.
 		fmt.Fprintf(sb, "    <polyline points=\"%d,%d %d,%d %d,%d\" "+
 			"stroke=\"#fff\" stroke-width=\"1.5\" fill=\"none\" stroke-linecap=\"round\" stroke-linejoin=\"round\"/>\n",
 			cx-3, cy, cx-1, cy+3, cx+4, cy-3)
@@ -327,10 +558,25 @@ func chipColor(job model.Job) string {
 		return "#fc6d26"
 	case "delayed":
 		return "#fca326"
+	case "on_failure":
+		return "#d9534f"
 	}
 	return "#1f75cb"
 }
 
+// imageString extracts the image name from a job Image field (string or map form).
+func imageString(img any) string {
+	switch v := img.(type) {
+	case string:
+		return v
+	case map[string]any:
+		if name, ok := v["name"].(string); ok {
+			return name
+		}
+	}
+	return ""
+}
+
 func svgEsc(s string) string {
 	s = strings.ReplaceAll(s, "&", "&amp;")
 	s = strings.ReplaceAll(s, "<", "&lt;")
@@ -356,3 +602,179 @@ func svgEmpty() string {
 			`</svg>`,
 		w, h, w, h, w/2, h/2)
 }
+
+// htmlPage wraps an SVG pipeline graph in a self-contained HTML page with
+// mouse pan/zoom and a job-detail sidebar that appears on chip click.
+func htmlPage(svgContent string) string {
+	var sb strings.Builder
+	sb.WriteString(`<!DOCTYPE html>
+<html lang="en">
+<head>
+<meta charset="UTF-8">
+<meta name="viewport" content="width=device-width,initial-scale=1">
+<title>Pipeline Graph</title>
+<style>
+*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
+body {
+  font-family: 'Segoe UI', Arial, sans-serif;
+  background: #f5f5f5;
+  display: flex;
+  height: 100vh;
+  overflow: hidden;
+}
+#sidebar {
+  width: 260px;
+  flex-shrink: 0;
+  background: #fff;
+  border-right: 1px solid #e0e0e0;
+  display: none;
+  flex-direction: column;
+  overflow-y: auto;
+}
+#sidebar.open { display: flex; }
+#sidebar-header {
+  display: flex;
+  align-items: center;
+  justify-content: space-between;
+  padding: .6rem .8rem;
+  border-bottom: 1px solid #e0e0e0;
+  background: #fafafa;
+  flex-shrink: 0;
+}
+#sidebar-header h3 {
+  font-size: .9rem;
+  color: #303030;
+  word-break: break-all;
+}
+#close-btn {
+  background: none;
+  border: none;
+  cursor: pointer;
+  font-size: 1rem;
+  color: #868686;
+  padding: .2rem .4rem;
+  margin-left: .4rem;
+  flex-shrink: 0;
+}
+#close-btn:hover { color: #303030; }
+#sidebar-body { padding: .8rem; flex: 1; }
+#sidebar-body pre {
+  font-size: .82rem;
+  color: #555;
+  white-space: pre-wrap;
+  line-height: 1.6;
+}
+#viewport {
+  flex: 1;
+  overflow: hidden;
+  cursor: grab;
+  position: relative;
+  background: #f5f5f5;
+}
+#viewport.dragging { cursor: grabbing; }
+#svg-wrap {
+  display: inline-block;
+  transform-origin: 0 0;
+  padding: 20px;
+}
+g[data-job] { cursor: pointer; }
+g[data-job]:hover > rect { stroke: #1f75cb; stroke-width: 2; }
+</style>
+</head>
+<body>
+<div id="sidebar">
+  <div id="sidebar-header">
+    <h3 id="sidebar-title">Job details</h3>
+    <button id="close-btn" title="Close">&#x2715;</button>
+  </div>
+  <div id="sidebar-body">
+    <pre id="sidebar-details"></pre>
+  </div>
+</div>
+<div id="viewport">
+  <div id="svg-wrap">
+`)
+	sb.WriteString(svgContent)
+	sb.WriteString(`
+  </div>
+</div>
+<script>
+(function() {
+  'use strict';
+  var vp = document.getElementById('viewport');
+  var wrap = document.getElementById('svg-wrap');
+  var sidebar = document.getElementById('sidebar');
+  var titleEl = document.getElementById('sidebar-title');
+  var detailsEl = document.getElementById('sidebar-details');
+  var tx = 0, ty = 0, scale = 1;
+
+  function applyTransform() {
+    wrap.style.transform = 'translate(' + tx + 'px,' + ty + 'px) scale(' + scale + ')';
+  }
+
+  // Zoom toward the cursor position.
+  vp.addEventListener('wheel', function(e) {
+    e.preventDefault();
+    var factor = e.deltaY < 0 ? 1.1 : 1 / 1.1;
+    var r = vp.getBoundingClientRect();
+    var mx = e.clientX - r.left;
+    var my = e.clientY - r.top;
+    tx = mx - (mx - tx) * factor;
+    ty = my - (my - ty) * factor;
+    scale *= factor;
+    applyTransform();
+  }, { passive: false });
+
+  // Drag to pan (skip if clicking on a job chip).
+  var dragging = false, ox = 0, oy = 0;
+  vp.addEventListener('mousedown', function(e) {
+    if (e.target.closest('g[data-job]')) return;
+    dragging = true;
+    ox = e.clientX - tx;
+    oy = e.clientY - ty;
+    vp.classList.add('dragging');
+  });
+  window.addEventListener('mousemove', function(e) {
+    if (!dragging) return;
+    tx = e.clientX - ox;
+    ty = e.clientY - oy;
+    applyTransform();
+  });
+  window.addEventListener('mouseup', function() {
+    dragging = false;
+    vp.classList.remove('dragging');
+  });
+
+  // Double-click on the background to reset the view.
+  vp.addEventListener('dblclick', function(e) {
+    if (e.target.closest('g[data-job]')) return;
+    tx = 0; ty = 0; scale = 1;
+    applyTransform();
+  });
+
+  // Click a job chip to show its details in the sidebar.
+  document.addEventListener('click', function(e) {
+    var g = e.target.closest('g[data-job]');
+    if (!g) return;
+    var jobName = g.dataset.job;
+    var descEl = g.querySelector('desc');
+    var desc = descEl ? descEl.textContent : '';
+    titleEl.textContent = jobName;
+    detailsEl.textContent = desc;
+    sidebar.classList.add('open');
+  });
+
+  // Close the sidebar.
+  document.getElementById('close-btn').addEventListener('click', function() {
+    sidebar.classList.remove('open');
+  });
+  document.addEventListener('keydown', function(e) {
+    if (e.key === 'Escape') sidebar.classList.remove('open');
+  });
+})();
+</script>
+</body>
+</html>
+`)
+	return sb.String()
+}

internal/graph/render_test.go

@@ -5,6 +5,7 @@ import (
 	"strings"
 	"testing"
 
+	"git.k3nny.fr/glint/internal/cicontext"
 	"git.k3nny.fr/glint/internal/model"
 )
 
@@ -59,9 +60,20 @@ func TestChipColor(t *testing.T) {
 	if chipColor(model.Job{Trigger: "x"}) != "#6b4fbb" { t.Error("trigger color") }
 	if chipColor(model.Job{When: "manual"}) != "#fc6d26" { t.Error("manual color") }
 	if chipColor(model.Job{When: "delayed"}) != "#fca326" { t.Error("delayed color") }
+	if chipColor(model.Job{When: "on_failure"}) != "#d9534f" { t.Error("on_failure color") }
 	if chipColor(model.Job{}) != "#1f75cb" { t.Error("regular color") }
 }
 
+// ── imageString ───────────────────────────────────────────────────────────────
+
+func TestImageString(t *testing.T) {
+	if imageString("alpine") != "alpine" { t.Error("string form") }
+	if imageString(map[string]any{"name": "golang:1.21"}) != "golang:1.21" { t.Error("map form") }
+	if imageString(map[string]any{"other": "x"}) != "" { t.Error("map without name key") }
+	if imageString(nil) != "" { t.Error("nil") }
+	if imageString(42) != "" { t.Error("unexpected type") }
+}
+
 // ── drawChipIcon ──────────────────────────────────────────────────────────────
 
 func TestDrawChipIcon(t *testing.T) {
@@ -72,6 +84,7 @@ func TestDrawChipIcon(t *testing.T) {
 		{model.Job{Trigger: "x"}, "<polyline"},
 		{model.Job{When: "manual"}, "<polygon"},
 		{model.Job{When: "delayed"}, "<circle"},
+		{model.Job{When: "on_failure"}, "<line"},
 		{model.Job{}, "<polyline"},
 	}
 	for _, tc := range cases {
@@ -86,7 +99,7 @@ func TestDrawChipIcon(t *testing.T) {
 // ── pipelineSVG ───────────────────────────────────────────────────────────────
 
 func TestPipelineSVG_Empty(t *testing.T) {
-	svg := pipelineSVG(&model.Pipeline{})
+	svg := pipelineSVG(&model.Pipeline{}, nil)
 	if !strings.Contains(svg, "no jobs defined") {
 		t.Errorf("expected 'no jobs defined', got:\n%s", svg)
 	}
@@ -100,13 +113,32 @@ func TestPipelineSVG_ClassicMode(t *testing.T) {
 			"test-job":  {Name: "test-job", Stage: "test"},
 		},
 	}
-	svg := pipelineSVG(p)
+	svg := pipelineSVG(p, nil)
 	if !strings.Contains(svg, "<svg") { t.Error("expected <svg") }
 	if !strings.Contains(svg, "build-job") { t.Error("expected build-job") }
 	if !strings.Contains(svg, "test-job") { t.Error("expected test-job") }
-	// Classic mode connector
+	// Classic mode bus-bar draws <line> elements for connectors
-	if !strings.Contains(svg, "<polyline") && !strings.Contains(svg, "<line") {
+	if !strings.Contains(svg, "<line") {
-		t.Error("expected connector in classic mode")
+		t.Error("expected <line> connector in classic mode")
+	}
+}
+
+func TestPipelineSVG_ClassicMode_MultiJob(t *testing.T) {
+	// Two source jobs, two destination jobs → bus-bar with vertical segment
+	p := &model.Pipeline{
+		Stages: []string{"build", "test"},
+		Jobs: map[string]model.Job{
+			"build-a": {Name: "build-a", Stage: "build"},
+			"build-b": {Name: "build-b", Stage: "build"},
+			"test-a":  {Name: "test-a", Stage: "test"},
+			"test-b":  {Name: "test-b", Stage: "test"},
+		},
+	}
+	svg := pipelineSVG(p, nil)
+	// Bus bar: horizontal stubs from each src + dst, plus a vertical bus line
+	// and an arrowhead polygon for each dst job.
+	if !strings.Contains(svg, "<polygon") {
+		t.Error("expected arrowhead <polygon> in multi-job classic mode")
 	}
 }
 
@@ -118,7 +150,7 @@ func TestPipelineSVG_DAGMode(t *testing.T) {
 			"test-job":  {Name: "test-job", Stage: "test", Needs: []any{"build-job"}},
 		},
 	}
-	svg := pipelineSVG(p)
+	svg := pipelineSVG(p, nil)
 	// DAG mode draws <path> bezier curves
 	if !strings.Contains(svg, "<path") {
 		t.Error("expected <path> connector in DAG mode")
@@ -126,7 +158,7 @@ func TestPipelineSVG_DAGMode(t *testing.T) {
 }
 
 func TestPipelineSVG_DAGMode_StraightConnector(t *testing.T) {
-	// Two stages at same height → straight <line> connector in classic mode
+	// Two stages at same height → straight connector in classic mode
 	p := &model.Pipeline{
 		Stages: []string{"a", "b"},
 		Jobs: map[string]model.Job{
@@ -134,7 +166,7 @@ func TestPipelineSVG_DAGMode_StraightConnector(t *testing.T) {
 			"j2": {Name: "j2", Stage: "b"},
 		},
 	}
-	svg := pipelineSVG(p)
+	svg := pipelineSVG(p, nil)
 	if !strings.Contains(svg, "<svg") { t.Error("expected <svg") }
 }
 
@@ -145,13 +177,18 @@ func TestPipelineSVG_AllJobTypes(t *testing.T) {
 			"manual-job":     {Name: "manual-job", Stage: "deploy", When: "manual"},
 			"delayed-job":    {Name: "delayed-job", Stage: "deploy", When: "delayed"},
 			"trigger-job":    {Name: "trigger-job", Stage: "deploy", Trigger: "other/project"},
+			"onfailure-job":  {Name: "onfailure-job", Stage: "deploy", When: "on_failure"},
 		},
 	}
-	svg := pipelineSVG(p)
+	svg := pipelineSVG(p, nil)
-	// Each type has its own color in the SVG
 	if !strings.Contains(svg, "#fc6d26") { t.Error("expected manual color") }
 	if !strings.Contains(svg, "#fca326") { t.Error("expected delayed color") }
 	if !strings.Contains(svg, "#6b4fbb") { t.Error("expected trigger color") }
+	if !strings.Contains(svg, "#d9534f") { t.Error("expected on_failure color") }
+	// on_failure chips have a dashed border
+	if !strings.Contains(svg, `stroke-dasharray="4,3"`) {
+		t.Error("expected dashed border on on_failure chip")
+	}
 }
 
 func TestPipelineSVG_JobNoStage(t *testing.T) {
@@ -160,7 +197,7 @@ func TestPipelineSVG_JobNoStage(t *testing.T) {
 			"myjob": {Name: "myjob"},
 		},
 	}
-	svg := pipelineSVG(p)
+	svg := pipelineSVG(p, nil)
 	if !strings.Contains(svg, "myjob") { t.Error("expected myjob") }
 }
 
@@ -172,10 +209,85 @@ func TestPipelineSVG_CrossPipelineNeed(t *testing.T) {
 				Needs: []any{map[string]any{"pipeline": "other", "job": "x"}}},
 		},
 	}
-	svg := pipelineSVG(p)
+	svg := pipelineSVG(p, nil)
 	if !strings.Contains(svg, "<svg") { t.Error("expected <svg") }
 }
 
+func TestPipelineSVG_Tooltip(t *testing.T) {
+	p := &model.Pipeline{
+		Stages: []string{"build"},
+		Jobs: map[string]model.Job{
+			"build-job": {
+				Name:  "build-job",
+				Stage: "build",
+				When:  "on_success",
+				Image: "golang:1.21",
+				Needs: []any{"prep-job"},
+			},
+		},
+	}
+	svg := pipelineSVG(p, nil)
+	// Tooltip <title> and <desc> should appear inside the <g data-job> wrapper
+	if !strings.Contains(svg, `<title>build-job</title>`) {
+		t.Error("expected <title>build-job</title>")
+	}
+	if !strings.Contains(svg, `<desc>`) {
+		t.Error("expected <desc> element")
+	}
+	if !strings.Contains(svg, "image: golang:1.21") {
+		t.Error("expected image in desc")
+	}
+	if !strings.Contains(svg, "needs: prep-job") {
+		t.Error("expected needs in desc")
+	}
+	if !strings.Contains(svg, `data-job="build-job"`) {
+		t.Error("expected data-job attribute")
+	}
+}
+
+func TestPipelineSVG_SkippedJob(t *testing.T) {
+	// A job with rules that never match in the given context should be greyed out.
+	p := &model.Pipeline{
+		Stages: []string{"deploy"},
+		Jobs: map[string]model.Job{
+			"deploy-job": {
+				Name:   "deploy-job",
+				Stage:  "deploy",
+				Script: []any{"deploy.sh"},
+				Rules: []model.Rule{
+					{If: `$CI_COMMIT_TAG != ""`, When: "on_success"},
+				},
+			},
+		},
+	}
+	// Branch context: CI_COMMIT_TAG is empty → rule doesn't match → job skipped
+	ctx := cicontext.New("main", "", "push", nil)
+	svg := pipelineSVG(p, ctx)
+
+	// Skipped jobs use grey (#868686) instead of the regular blue
+	if !strings.Contains(svg, `fill="#868686"`) {
+		t.Error("expected grey fill for skipped job circle")
+	}
+	// Skipped state should appear in the tooltip desc
+	if !strings.Contains(svg, "state: skipped") {
+		t.Error("expected 'state: skipped' in tooltip desc")
+	}
+}
+
+func TestPipelineSVG_ContextNil(t *testing.T) {
+	// nil context → no skipped jobs, regular colors
+	p := &model.Pipeline{
+		Stages: []string{"build"},
+		Jobs: map[string]model.Job{
+			"j": {Name: "j", Stage: "build"},
+		},
+	}
+	svg := pipelineSVG(p, nil)
+	if !strings.Contains(svg, `fill="#1f75cb"`) {
+		t.Error("expected regular blue fill with nil context")
+	}
+}
+
 // ── RenderPipeline ────────────────────────────────────────────────────────────
 
 func TestRenderPipeline(t *testing.T) {
@@ -186,7 +298,7 @@ func TestRenderPipeline(t *testing.T) {
 		},
 	}
 	dir := t.TempDir()
-	path, err := RenderPipeline(p, dir)
+	path, err := RenderPipeline(p, dir, nil)
 	if err != nil {
 		t.Fatalf("RenderPipeline: %v", err)
 	}
@@ -202,7 +314,7 @@ func TestRenderPipeline_InvalidDir(t *testing.T) {
 	if err := os.WriteFile(filePath, []byte("x"), 0o644); err != nil {
 		t.Fatal(err)
 	}
-	_, err := RenderPipeline(&model.Pipeline{}, filePath+"/nested")
+	_, err := RenderPipeline(&model.Pipeline{}, filePath+"/nested", nil)
 	if err == nil {
 		t.Error("expected error writing to path under a file")
 	}
@@ -222,7 +334,7 @@ func TestRenderPipeline_WriteFileFails(t *testing.T) {
 		Stages: []string{"build"},
 		Jobs:   map[string]model.Job{"j": {Name: "j", Stage: "build"}},
 	}
-	_, err := RenderPipeline(p, dir)
+	_, err := RenderPipeline(p, dir, nil)
 	if err == nil {
 		t.Error("expected error when writing SVG to read-only directory")
 	}
@@ -241,7 +353,7 @@ func TestRenderPipeline_SVGFallback(t *testing.T) {
 		Jobs:   map[string]model.Job{"j": {Name: "j", Stage: "build"}},
 	}
 	dir := t.TempDir()
-	path, err := RenderPipeline(p, dir)
+	path, err := RenderPipeline(p, dir, nil)
 	if err != nil {
 		t.Fatalf("RenderPipeline: %v", err)
 	}
@@ -264,7 +376,7 @@ func TestConvertToPNG_NoConverter(t *testing.T) {
 
 func TestConvertToPNG_FakeConverter(t *testing.T) {
 	// Install a fake rsvg-convert that just creates the output file and exits 0.
-	// This exercises the "return true" branch (line 72) and os.Remove in RenderPipeline.
+	// This exercises the "return true" branch and os.Remove in RenderPipeline.
 	binDir := t.TempDir()
 	script := "#!/bin/sh\n# rsvg-convert --output <out> <in>\ncp \"$3\" \"$2\"\n"
 	fakeBin := binDir + "/rsvg-convert"
@@ -303,7 +415,7 @@ func TestRenderPipeline_PNGConversion(t *testing.T) {
 		Jobs:   map[string]model.Job{"j": {Name: "j", Stage: "build"}},
 	}
 	dir := t.TempDir()
-	path, err := RenderPipeline(p, dir)
+	path, err := RenderPipeline(p, dir, nil)
 	if err != nil {
 		t.Fatalf("RenderPipeline: %v", err)
 	}
@@ -315,7 +427,7 @@ func TestRenderPipeline_PNGConversion(t *testing.T) {
 // ── pipelineSVG coverage gaps ─────────────────────────────────────────────────
 
 func TestPipelineSVG_LShapedElbow(t *testing.T) {
-	// Classic mode with unequal stage sizes → different column heights → L-shaped elbow
+	// Classic mode with unequal stage sizes → vertical bus bar required
 	p := &model.Pipeline{
 		Stages: []string{"build", "test"},
 		Jobs: map[string]model.Job{
@@ -324,9 +436,10 @@ func TestPipelineSVG_LShapedElbow(t *testing.T) {
 			"j3": {Name: "j3", Stage: "test"},
 		},
 	}
-	svg := pipelineSVG(p)
+	svg := pipelineSVG(p, nil)
-	if !strings.Contains(svg, "<polyline") {
+	// The bus bar is a <line>; arrowheads are <polygon>
-		t.Error("expected <polyline> for L-shaped elbow connector")
+	if !strings.Contains(svg, "<polygon") {
+		t.Error("expected <polygon> arrowhead in bus-bar connector")
 	}
 }
 
@@ -339,9 +452,214 @@ func TestPipelineSVG_DAGNeedNotInPositionMap(t *testing.T) {
 			".hidden-template": {Name: ".hidden-template", Stage: "build"},
 		},
 	}
-	svg := pipelineSVG(p)
+	svg := pipelineSVG(p, nil)
 	// Should render without panic; .hidden-template is not visible so no connector drawn.
 	if !strings.Contains(svg, "<svg") {
 		t.Error("expected valid SVG output")
 	}
 }
+
+// ── RenderHTML ────────────────────────────────────────────────────────────────
+
+func TestRenderHTML(t *testing.T) {
+	p := &model.Pipeline{
+		Stages: []string{"build"},
+		Jobs: map[string]model.Job{
+			"build-job": {Name: "build-job", Stage: "build"},
+		},
+	}
+	dir := t.TempDir()
+	path, err := RenderHTML(p, dir, nil)
+	if err != nil {
+		t.Fatalf("RenderHTML: %v", err)
+	}
+	if !strings.HasSuffix(path, ".html") {
+		t.Errorf("expected .html output, got %q", path)
+	}
+	data, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatalf("reading output: %v", err)
+	}
+	html := string(data)
+	if !strings.Contains(html, "<!DOCTYPE html>") { t.Error("expected DOCTYPE") }
+	if !strings.Contains(html, "<svg") { t.Error("expected embedded <svg") }
+	if !strings.Contains(html, "build-job") { t.Error("expected job name in HTML") }
+	if !strings.Contains(html, "applyTransform") { t.Error("expected JS pan/zoom function") }
+	if !strings.Contains(html, "sidebar") { t.Error("expected sidebar element") }
+}
+
+func TestRenderHTML_InvalidDir(t *testing.T) {
+	dir := t.TempDir()
+	filePath := dir + "/notadir"
+	if err := os.WriteFile(filePath, []byte("x"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	_, err := RenderHTML(&model.Pipeline{}, filePath+"/nested", nil)
+	if err == nil {
+		t.Error("expected error writing to path under a file")
+	}
+}
+
+func TestRenderHTML_WriteFileFails(t *testing.T) {
+	if os.Getuid() == 0 {
+		t.Skip("skipping as root — file permissions don't apply")
+	}
+	dir := t.TempDir()
+	if err := os.Chmod(dir, 0o555); err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { os.Chmod(dir, 0o755) })
+
+	p := &model.Pipeline{
+		Stages: []string{"build"},
+		Jobs:   map[string]model.Job{"j": {Name: "j", Stage: "build"}},
+	}
+	_, err := RenderHTML(p, dir, nil)
+	if err == nil {
+		t.Error("expected error when writing HTML to read-only directory")
+	}
+}
+
+// ── computeColumns ────────────────────────────────────────────────────────────
+
+func TestComputeColumns_NoIntraNeeds(t *testing.T) {
+	// No intra-stage needs → one column per stage.
+	stages := []string{"build", "test"}
+	byStage := map[string][]string{
+		"build": {"build-a", "build-b"},
+		"test":  {"test-a"},
+	}
+	jobs := map[string]model.Job{
+		"build-a": {Name: "build-a", Stage: "build"},
+		"build-b": {Name: "build-b", Stage: "build"},
+		"test-a":  {Name: "test-a", Stage: "test"},
+	}
+	cols := computeColumns(stages, byStage, jobs)
+	if len(cols) != 2 {
+		t.Fatalf("expected 2 columns (one per stage), got %d", len(cols))
+	}
+	if cols[0].stage != "build" || len(cols[0].jobs) != 2 {
+		t.Errorf("col[0]: got stage=%q jobs=%v", cols[0].stage, cols[0].jobs)
+	}
+	if cols[1].stage != "test" || len(cols[1].jobs) != 1 {
+		t.Errorf("col[1]: got stage=%q jobs=%v", cols[1].stage, cols[1].jobs)
+	}
+}
+
+func TestComputeColumns_IntraNeeds(t *testing.T) {
+	// job-b depends on job-a in the same stage → split into 2 sub-columns.
+	stages := []string{"build"}
+	byStage := map[string][]string{
+		"build": {"job-a", "job-b"},
+	}
+	jobs := map[string]model.Job{
+		"job-a": {Name: "job-a", Stage: "build"},
+		"job-b": {Name: "job-b", Stage: "build", Needs: []any{"job-a"}},
+	}
+	cols := computeColumns(stages, byStage, jobs)
+	if len(cols) != 2 {
+		t.Fatalf("expected 2 sub-columns, got %d", len(cols))
+	}
+	// Both belong to the same stage.
+	if cols[0].stage != "build" || cols[1].stage != "build" {
+		t.Error("both sub-columns should be in stage 'build'")
+	}
+	// job-a has no same-stage deps → depth 0 → first sub-column.
+	if len(cols[0].jobs) != 1 || cols[0].jobs[0] != "job-a" {
+		t.Errorf("col[0] should contain job-a, got %v", cols[0].jobs)
+	}
+	// job-b depends on job-a → depth 1 → second sub-column.
+	if len(cols[1].jobs) != 1 || cols[1].jobs[0] != "job-b" {
+		t.Errorf("col[1] should contain job-b, got %v", cols[1].jobs)
+	}
+}
+
+func TestComputeColumns_EmptyStageSkipped(t *testing.T) {
+	// Stages with no jobs are silently skipped.
+	stages := []string{"build", "empty", "test"}
+	byStage := map[string][]string{
+		"build": {"j1"},
+		"test":  {"j2"},
+	}
+	jobs := map[string]model.Job{
+		"j1": {Name: "j1", Stage: "build"},
+		"j2": {Name: "j2", Stage: "test"},
+	}
+	cols := computeColumns(stages, byStage, jobs)
+	if len(cols) != 2 {
+		t.Fatalf("expected 2 columns (empty stage skipped), got %d", len(cols))
+	}
+}
+
+func TestComputeColumns_CrossStageNeedIgnored(t *testing.T) {
+	// job-b has needs: for both job-a (same stage) and prev-job (different stage).
+	// The cross-stage need must be ignored when computing topological depth.
+	stages := []string{"build"}
+	byStage := map[string][]string{
+		"build": {"job-a", "job-b"},
+	}
+	jobs := map[string]model.Job{
+		"job-a": {Name: "job-a", Stage: "build"},
+		"job-b": {Name: "job-b", Stage: "build", Needs: []any{"job-a", "prev-job"}},
+		"prev-job": {Name: "prev-job", Stage: "prepare"},
+	}
+	cols := computeColumns(stages, byStage, jobs)
+	// Still split into 2 sub-columns; the cross-stage need is ignored.
+	if len(cols) != 2 {
+		t.Fatalf("expected 2 sub-columns, got %d", len(cols))
+	}
+	if cols[0].jobs[0] != "job-a" {
+		t.Errorf("expected job-a in first sub-column, got %v", cols[0].jobs)
+	}
+	if cols[1].jobs[0] != "job-b" {
+		t.Errorf("expected job-b in second sub-column, got %v", cols[1].jobs)
+	}
+}
+
+func TestComputeColumns_CycleGuard(t *testing.T) {
+	// Intra-stage cycle must not hang (cycle guard returns depth 0).
+	stages := []string{"build"}
+	byStage := map[string][]string{
+		"build": {"a", "b"},
+	}
+	jobs := map[string]model.Job{
+		"a": {Name: "a", Stage: "build", Needs: []any{"b"}},
+		"b": {Name: "b", Stage: "build", Needs: []any{"a"}},
+	}
+	cols := computeColumns(stages, byStage, jobs)
+	// Should return without hanging; exact column count is implementation-defined.
+	if len(cols) == 0 {
+		t.Error("expected at least one column")
+	}
+}
+
+func TestPipelineSVG_IntraStageDAG(t *testing.T) {
+	// job-b depends on job-a in the same stage → SVG should render both,
+	// placed as sub-columns (sub-stage gap between them).
+	p := &model.Pipeline{
+		Stages: []string{"build"},
+		Jobs: map[string]model.Job{
+			"job-a": {Name: "job-a", Stage: "build"},
+			"job-b": {Name: "job-b", Stage: "build", Needs: []any{"job-a"}},
+		},
+	}
+	svg := pipelineSVG(p, nil)
+	if !strings.Contains(svg, "job-a") { t.Error("expected job-a in SVG") }
+	if !strings.Contains(svg, "job-b") { t.Error("expected job-b in SVG") }
+	// DAG mode: bezier connectors between the two jobs.
+	if !strings.Contains(svg, "<path") {
+		t.Error("expected bezier <path> connector between intra-stage jobs")
+	}
+}
+
+// ── htmlPage ──────────────────────────────────────────────────────────────────
+
+func TestHtmlPage(t *testing.T) {
+	svgContent := `<svg xmlns="http://www.w3.org/2000/svg" width="100" height="50"><rect/></svg>`
+	html := htmlPage(svgContent)
+	if !strings.Contains(html, "<!DOCTYPE html>") { t.Error("expected DOCTYPE") }
+	if !strings.Contains(html, svgContent) { t.Error("expected SVG embedded in HTML") }
+	if !strings.Contains(html, "id=\"viewport\"") { t.Error("expected viewport element") }
+	if !strings.Contains(html, "id=\"sidebar\"") { t.Error("expected sidebar element") }
+	if !strings.Contains(html, "applyTransform") { t.Error("expected JS transform function") }
+}

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 ]]