English | 繁體中文

Compass — The Compass of PRD Discipline

A Claude Code skill that keeps your implementation true to the spec — build to the PRD, no drift, no dropped items, no half-finished work. Part of a four-skill toolchain: Cartographer draws the map → Compass walks it → Sentinel stands guard → Lookout watches from the mast.

---

The problem it solves

The three most common failure modes once you have a PRD and start building:

1. Drift — halfway in you realize you've strayed from the PRD, but 3 days of code are already written and there's no easy way back.
2. Dropped items — the checklist says "auth, 12 endpoints ⬜"; you finish 9, check it off, and the other 3 are never written — nobody notices.
3. Half-finished — you reach 70%, leave a TODO: circle back, and "later" never comes.

Compass blocks all three with discipline + tool enforcement (exit codes, not willpower).

How it works

Four core beliefs:

1. PRD is a contract, not a suggestion — every deviation is logged, aligned, and ruled on.
2. Done means done — ship in small slices if you like, but never half-finished phases.
3. Rely on exit codes, not discipline — mechanical checks beat stated rules, by a lot.
4. Brownfield needs discipline too — PRD discipline isn't only for greenfield.

11 topic modules (loaded on demand from references/):

§1  Foundations          five phases + core principles
§2  Definition of Ready  pre-flight PRD health check
§3  Implementation       in-flight SOP
§4  Quality Gates        acceptance / self-review / tool enforcement
§5  Conflict Handling    vague / bug / gap + mid-flight change / cross-doc / multi-PRD
§6  Non-Functional       performance / observability / security / a11y / SLA
§7  Operations           migration / rollback / deployment
§8  Brownfield           working inside an existing codebase
§9  Collaboration        cross-person / cross-AI
§10 Testing Strategy     unit / integration / e2e split
§11 Tooling              M-007~M-010 tool enforcement + general scripts

Quick start

# Install as a user-level skill (applies to all projects)
mkdir -p ~/.claude/skills/compass
cp -r SKILL.md references scripts templates ~/.claude/skills/compass/

# Verify
ls ~/.claude/skills/compass   # → SKILL.md  references  scripts  templates

Full guide (skill + tool scripts + templates) in docs/INSTALL.md.

The toolchain

Compass is the build-to-spec stage of a four-skill toolchain — each watches a different thing:

Skill	Role	Watches
Cartographer	draws the map	turning a fuzzy idea into a solid PRD
Compass	walks the map	are you following the PRD? (build to spec, no drift)
Sentinel	stands guard	how you think (shallow vs. deep, symptom vs. root cause)
Lookout	watches from the mast	independent-context code review

Cartographer draws the map → Compass walks it → Sentinel stands guard → Lookout watches. Full division of labor in docs/SCOPE.md.

Structure

compass/
├── SKILL.md            skill entry (loaded by Claude Code)
├── references/         11 modules, loaded on demand
├── scripts/            tool-enforcement scripts (lint / audit)
├── templates/          PRD checklist / progress / dev-log templates
├── docs/               DESIGN · INSTALL · SCOPE
└── compass-zh/         Traditional Chinese mirror

Docs

• DESIGN — design philosophy, key decisions & trade-offs
• INSTALL — full install (skill + scripts + templates) & verification
• SCOPE — what it covers, what it doesn't, and the toolchain split

License

MIT © Ray_Li

A portfolio piece exploring "how to encode the discipline of PRD-driven development into an AI coding partner." Its companion Sentinel explores "how to encode structured thinking into an AI coding partner."