AI Project Engineer

Skills for the start of a product, and for the beats after it. project-foundation writes the pack an engineer builds from: a brief, PRD, personas, user journeys, sitemap, system design, data model and API, MVP slice, and risks. The later skills keep that pack coherent: a living architecture file, Zod contracts before UI, one presentational screen, one verifiable chunk, kill tests, refusal lines, a spec-drift check, and a project-state file each session reads first and writes last.

They are small and composable. Hack on them. The files in your project are yours.

Two ways in. The Claude Code plugin installs the set as a bundle. npx skills copies the skill folders into your project so you can edit them. Installing both leaves you with every skill twice.

Install

Claude Code

/plugin marketplace add yasmnngls/ai-project-engineer
/plugin install ai-project-engineer@ai-project-engineer
/reload-plugins

The catalog is .claude-plugin/marketplace.json. A skill command is /ai-project-engineer:<skill-name>.

From a local checkout:

/plugin marketplace add ./path-to-this-repo
/plugin install ai-project-engineer@ai-project-engineer

Cursor, Codex, and other agents

npx skills@latest add yasmnngls/ai-project-engineer

Pick the skills you want. After that, /project-foundation and the other names work without the plugin prefix.

Cursor can also add https://github.com/yasmnngls/ai-project-engineer as a marketplace and install AI Project Engineer. The catalog is .cursor-plugin/marketplace.json.

claude.ai

Package one zip per skill, then upload each zip under Customize, Skills. Code execution has to be on, because each skill runs a Python check.

python3 scripts/package_claude_skill.py

That writes dist/<skill-name>.zip. The zip root is the skill folder, with SKILL.md inside it. claude.ai skills stay on claude.ai. They do not sync to Claude Code or Cursor.

Maintainers of this repo

bash scripts/link-skills.sh

That symlinks skills/engineering/* into ~/.claude/skills, ~/.agents/skills, and ~/.cursor/skills.

Use it

Open the product repo and describe the job:

/project-foundation
Field technicians need a phone page to record a site visit before they drive away. The office reads submitted visits. First version has no accounts.

If the user and the job are already named, the skill writes docs/foundation/ in that turn. If either is missing, it asks once and waits.

Facts the user stated, facts read from the repo, and choices the skill made are tagged [stated], [inferred], and [assumption].

Build in beats after that. A session that tries to ship a whole feature goes back to the current beat.

Reference

These skills live in skills/engineering/. Each one is model-invoked: you can type it, and the model can reach for it when the task fits. Human-facing pages are under docs/engineering/.

• project-foundation: Writes the ten-file foundation pack before any product code.
• architecture-memory: Writes ARCHITECTURE.md and the craft rules the next session reads.
• one-chunk: Implements one beat of the MVP: contract, shell, or wire.
• lock-contracts: Writes Zod schemas and discriminated results before UI.
• state-shell: Builds one screen as a state union plus a presentational view.
• assumption-trial: Writes a kill test for each load-bearing assumption.
• say-no: Writes the refusal for each excluded capability.
• spec-drift: Compares the code to the pack and reports contradictions, gaps, and hardened assumptions.
• project-state: Keeps PROJECT-STATE.md: current focus, next actions, one source of truth per domain, and what to read for each task.
• diagnose: Writes docs/bugs/<slug>.md: a red loop, ranked falsifiable hypotheses, a regression test before the fix, and a cleanup the validator checks against the repo.
• review-diff: Reviews the diff since a fixed point: validators and project checks first, then Standards and Spec against the current chunk, with a ship or fix verdict.
• ship-gate: Gates a release: every check passes, each shipped requirement has a test or route, env var names, one rollback step, and what was left out.

The order once a product repo exists:

1. project-foundation writes docs/foundation/.
2. architecture-memory writes ARCHITECTURE.md.
3. one-chunk performs a single beat.
4. On a contract beat, lock-contracts writes the schemas.
5. On a shell beat, state-shell writes the state model and the view.
6. On a wire beat, connect the shell to the contracts and add one test of what the user sees.

assumption-trial, say-no, and spec-drift read the pack. They do not replace steps 3 to 6.

project-state opens and closes each session. A new session reads PROJECT-STATE.md first. In an existing repo without a pack, project-state is the first skill to run.

review-diff closes a beat or a branch. diagnose takes a bug from symptom to regression test. ship-gate decides ship or hold before a release.

Check a pack

python3 skills/engineering/project-foundation/scripts/validate_foundation.py docs/foundation

examples/field-notes is a finished pack for a site-visit log. It exists so the validator has a known-good fixture. The skill is instructed not to copy it into a new project.

python3 skills/engineering/project-foundation/scripts/validate_foundation.py examples/field-notes
python3 skills/engineering/assumption-trial/scripts/validate_trials.py examples/field-notes/09-assumption-trials.md
python3 skills/engineering/say-no/scripts/validate_refusals.py examples/field-notes/10-refusals.md
python3 skills/engineering/spec-drift/scripts/validate_drift.py examples/drift-found/11-drift.md
python3 skills/engineering/architecture-memory/scripts/validate_architecture.py ARCHITECTURE.md
python3 skills/engineering/lock-contracts/scripts/validate_contracts.py examples/site-log/src/contracts
python3 skills/engineering/state-shell/scripts/validate_shell.py examples/site-log/src/features/visit
python3 skills/engineering/one-chunk/scripts/validate_chunk.py examples/chunk/12-chunk.md
python3 skills/engineering/project-state/scripts/validate_project_state.py examples/project-state/PROJECT-STATE.md
python3 skills/engineering/diagnose/scripts/validate_diagnosis.py examples/diagnosis/whitespace-note.md --root examples/diagnosis
python3 skills/engineering/review-diff/scripts/validate_review.py examples/review/2026-10-04-step4-shell.md
python3 skills/engineering/ship-gate/scripts/validate_release.py examples/release/0.1.0.md --prd examples/field-notes/01-prd.md --slice examples/field-notes/07-mvp-slice.md

Layout

.claude-plugin/          Claude Code plugin and marketplace
.cursor-plugin/          Cursor marketplace
skills/engineering/      one folder per skill
docs/engineering/        human-facing page per skill
examples/                validator fixtures, not templates
rules/craft.mdc          constraints for product TypeScript
scripts/link-skills.sh   symlink skills into local harnesses