Code standards — the change workflow

You are making a code change. This skill is the execution order; it is stack-agnostic. Adapt every command to the project's actual toolchain: read the project's own docs (README, CONTRIBUTING, AGENTS.md/CLAUDE.md, a Makefile or package scripts) once to learn its build, test, lint, and format commands before you start.

Steps

1. Orient. Read any project lessons/gotchas file (e.g. tasks/lessons.md) and obey it. Find and read the one doc for the subsystem you're changing, not the whole tree.
2. Plan if non-trivial (3+ steps or an architectural choice): short plan in tasks/todo.md — files touched, tests to add, risks. Going sideways → stop and re-plan.
3. Baseline: get the project's build + test command green before touching anything. A pre-existing red is the first task; never build on top of a broken baseline.
4. Implement the smallest root-cause change. Hand-match the surrounding style. Don't run a mass auto-formatter on files you touch; it buries your real diff in noise.
5. Test: new behavior gets a test that fails without the change; security gates get negative-assertion tests (wrong token → denied, state unchanged, no data leak).
6. Verify: run the full check suite (build + lint + type-check + tests) until green before you call it "done".
7. Self-review your own diff as if it were someone else's PR (or invoke a review skill). Fix findings before presenting.
8. Close out: update docs in the same change; append to a lessons file if you were corrected or surprised; write a conventional commit message (feat|fix|docs(scope): …).

Tripwires — stop and re-check the project's guidelines when you're about to…

• change a public or shared interface (API, wire format, schema) → check every caller; prefer additive changes
• add a dependency → weigh transitive weight and licenses, and whether the stdlib already covers it
• touch auth, tokens, or permissions → audit every writer and reader path, add negative tests
• write a secret to disk → use the platform's atomic create-private API, never write-then-chmod
• hold a lock across an await/blocking call, or read env inside logic → extract a pure decision function

No-progress guard

The same failure surviving two fix attempts means stop: write the finding to your lessons file, mark the item [BLOCKED], and surface it. Don't thrash.