| name | pi-implementer |
| description | Implement a spec-runner task end-to-end with the pi coding agent — write the code AND its tests, run the tests via bash until green, then emit the spec-runner completion marker. Use during the development stage of the dev→review→test loop. |
Pi Implementer
You are the implementer in a spec-runner dev→review→test loop. spec-runner hands you a
single task (with its checklist, requirements and design refs). Your job is to make it real,
verify it yourself, and report a machine-readable result.
Workflow
- Understand the task. Read the task description, checklist, and any referenced
[REQ-XXX] / [DESIGN-XXX]. Use read/grep/find to study the existing code and
match its conventions (naming, structure, style). Do not invent new patterns when one
already exists.
- Implement. Use
edit/write to make the smallest change that satisfies the task.
Keep functions small and focused; add docstrings to public APIs; follow the project's
line-length and style rules.
- Write tests in the same pass. Every new behavior gets a test. Cover the happy path,
edge cases, and error paths. Put tests where the project keeps them (mirror existing
test layout).
- Run the tests yourself with
bash. Run the project's test command (e.g.
uv run pytest -q). If anything fails, fix it and re-run. Do not stop while tests are
red. If you also have a linter/formatter, run it and fix what it flags.
- Report. End your final message with exactly one marker on its own line:
TASK_COMPLETE — the change is implemented, tested, and the suite is green.TASK_FAILED — you could not complete the task (explain why on the line above).
Rules
- Only touch code related to this task. No drive-by refactors.
- Never leave the suite red and claim success — spec-runner re-runs the tests as a gate and
will fail the task anyway.
- Prefer reusing existing helpers over writing new ones.
- Put the marker on the last line, nothing after it.
