---
name: stdd-implement
description: "Execute one agreed behavior slice through docs, genuine red, implementation, and fresh verification. Use when: The behavior contract is agreed and production changes are ready to begin."
---

<!-- generated by stdd plugin build v0.11.0 — do not edit -->


# Implement

Run one narrow vertical slice at a time:

1. Record the docs decision with `stdd docs`. For changed behavior, edit the
   canonical docs first and record `updated-first`.
2. Add the smallest test that proves the agreed behavior. Run it through
   `stdd red -- <command>` and confirm the failure is genuine.
3. Implement only enough production code to satisfy that contract, in the
   shape the governing architecture and representative current code call
   for. Internals are your choice; escalate only when the contract, a
   committed interface, or the architecture would have to change.
4. Run the focused and affected verification through
   `stdd verify -- <command>`.
5. Check `stdd status --local`; a later checkout change makes verification
   stale and requires another verify.

When a recorded fact surprises you — a red graded not genuine, a verify
reported stale, a docs decision called contradicted — the recorder and
`stdd status` rules are in `.stdd/reference/commands.md`; open it then, not
before.

Frontend visual composition follows the method's design-first exception;
behavior embedded in the UI still follows the loop. Do not batch unrelated
rules behind one red, and tick a plan item only after its named evidence
exists.