[Extension]: Add linear

### Extension ID

linear

### Extension Name

Linear Storage Backend

### Version

1.0.0

### Description

Persists Spec-Driven Development artifacts (spec, plan, tasks, research, contracts, checklists, constitution) as Linear issues via the official Linear MCP server. Replaces local file storage; designed to be paired with the 'linear' preset.

### Author

speckit-linear (derobiwan)

### Repository URL

https://github.com/derobiwan/speckit-linear

### Download URL

https://github.com/derobiwan/speckit-linear/archive/refs/tags/v1.0.0.zip

### License

MIT

### Homepage (optional)

https://github.com/derobiwan/speckit-linear

### Documentation URL (optional)

https://github.com/derobiwan/speckit-linear/blob/main/README.md

### Changelog URL (optional)

https://github.com/derobiwan/speckit-linear/blob/main/CHANGELOG.md

### Required Spec Kit Version

>=0.8.0

### Required Tools (optional)

- Linear MCP server — configured via `claude mcp add -s user --transport http linear https://mcp.linear.app/mcp` (required)

### Number of Commands

16

### Number of Hooks (optional)

18

### Tags

linear, mcp, project-management, issue-tracking, spec-driven-development

### Key Features

- **Linear-as-storage-backend**: all Spec-Driven Development artifacts (`[CONSTITUTION]`, `[SPEC]`, `[PLAN]`, `[RESEARCH]`, `[DATA-MODEL]`, `[CONTRACT]`, `[QUICKSTART]`, `[CHECKLIST]`, individual tasks) become Linear issues — no local `specs/` directory created
- **Dual-label convention**: every issue carries one `speckit:` label plus a `feature:NNN-name` label, enabling filtering all issues for one feature
- **Idempotent on every command**: re-running `/speckit.specify`, `/speckit.plan`, etc. updates in place rather than creating duplicates (FR-031, non-negotiable)
- **Bounded retry**: 3 attempts with 1s/2s/4s ±25% jitter on 5xx/429/timeout; 4xx surfaces immediately (FR-032)
- **Structured JSON Lines logging**: every MCP attempt → `.specify/logs/linear-mcp.log` with secrets scrubbed (FR-034)
- **Backend confirmation banner**: `[linear] backend=Linear workspace= project=` printed once per process on stderr
- **Canonical Spec Kit sequence enforcement**: every preset command body carries a Workflow Position (MANDATORY) block that aborts if a required predecessor artifact is missing
- **30 supported AI agent integrations** via `specify init --ai --extension linear --preset linear`
- **Namespaced maintenance commands**: `/speckit.linear.repair`, `/speckit.linear.baseline`, `/speckit.linear.migrate`, `/speckit.linear.upgrade-from-v051`

### Testing Checklist

- [x] Extension follows `extension.yml` schema specification
- [x] README.md with installation and usage instructions
- [x] LICENSE file included (MIT)
- [x] GitHub release created with version tag (v1.0.0)
- [x] All command files exist and are properly formatted
- [x] Extension ID follows naming conventions (lowercase-with-hyphens)

### Testing Details

**Tested on:**
- macOS 14+ with Spec Kit v0.8.10
- Linux Ubuntu 22.04 with Spec Kit v0.8.10
- Python 3.11+ (matches upstream `requires-python`)

**Test project:** github.com/derobiwan/speckit-linear (self-hosted feature: `feature:053-community-catalog-publish`)

**Test scenarios:**
1. `specify init --ai claude --extension linear --preset linear` against a fresh project — completes successfully; `.specify/extensions.yml` and `.specify/config/linear.md` both registered
2. `/speckit.constitution` then `/speckit.specify` then `/speckit.plan` then `/speckit.tasks` then `/speckit.implement` against a sample feature — full canonical sequence produces 5 plan artifacts + milestone-prefixed task issues in Linear
3. Re-run of `/speckit.specify` for the same feature — updates the existing `[SPEC]` issue in place; no duplicate created (idempotency)
4. Force a 429 from the Linear MCP via rate-limiting — extension retries with 1s/2s/4s backoff and eventually succeeds
5. Scan release artifact with `gitleaks detect --source .` — 0 findings
6. Run full test suite (`pytest`) on the v1.0.0 tag — 3268 tests pass, 0 fail

### Example Usage

```bash
# One-time per machine: configure the Linear MCP server
claude mcp add -s user --transport http linear https://mcp.linear.app/mcp

# In any new project:
specify init --ai claude --extension linear --preset linear

# Then follow the canonical Spec Kit sequence:
/speckit.constitution # one-time per repo
/speckit.specify "Add user authentication"
/speckit.clarify # optional, before plan
/speckit.plan
/speckit.checklist # optional, after plan
/speckit.tasks
/speckit.analyze # optional, after tasks
/speckit.implement
```

All artifacts persist as Linear issues with dual labels (`speckit:spec` + `feature:NNN-name`). No local `specs/` directory is created.

### Proposed Catalog Entry

```json
{
"linear": {
"name": "Linear Storage Backend",
"id": "linear",
"description": "Persists Spec-Driven Development artifacts (spec, plan, tasks, research, contracts, checklists, constitution) as Linear issues via the official Linear MCP server. Replaces local file storage; designed to be paired with the 'linear' preset.",
"author": "speckit-linear",
"version": "1.0.0",
"download_url": "https://github.com/derobiwan/speckit-linear/archive/refs/tags/v1.0.0.zip",
"repository": "https://github.com/derobiwan/speckit-linear",
"homepage": "https://github.com/derobiwan/speckit-linear",
"documentation": "https://github.com/derobiwan/speckit-linear/blob/main/README.md",
"changelog": "https://github.com/derobiwan/speckit-linear/blob/main/CHANGELOG.md",
"license": "MIT",
"requires": {
"speckit_version": ">=0.8.0"
},
"provides": {
"commands": 16,
"hooks": 18
},
"tags": [
"linear",
"mcp",
"project-management",
"issue-tracking",
"spec-driven-development"
],
"verified": false,
"downloads": 0,
"stars": 0,
"created_at": "2026-05-16T00:00:00Z",
"updated_at": "2026-05-16T00:00:00Z"
}
}
```

### Additional Context

This extension is paired with the `linear` preset (submitted separately as a PR — see `presets/catalog.community.json` submission). The pair installs together via `specify init --ai --extension linear --preset linear` and replaces local-file storage with Linear-as-storage-backend.

The preset wraps 9 core `/speckit.*` command templates (`speckit.constitution`, `speckit.specify`, `speckit.clarify`, `speckit.plan`, `speckit.tasks`, `speckit.checklist`, `speckit.analyze`, `speckit.implement`, `speckit.taskstoissues`) so they persist artifacts to Linear instead of local files. The extension adds 16 `/speckit.linear.*` commands and 18 hooks (one `before_*` + one `after_*` per lifecycle phase).

Constitutional invariants observed:
- No patches to `src/specify_cli/` (Plugin-P1 — contributions limited to upstream catalog files)
- Linear MCP server is the only credential boundary (Plugin-P8 — no tokens or workspace IDs bundled in the artifact)
- No local-file fallback on MCP failure (Plugin-P2)

Pre-publication scans: gitleaks → 0 findings; `grep -ri "derobiwan@"` on the v1.0.0 tree → 0 hits; 3268 tests pass.