/implement

description: Execute a plan document while keeping progress synchronized.

/implement [plan-file-path]

Implement a plan and keep its checklist current as you go. A bare filename means `nimbalyst-local/plans/<name>`.

Steps

1. **Read the whole plan.** Missing file: ask for the path. No frontmatter: warn it isn't a plan. Already complete or `blocked`: ask before proceeding.

2. **Link the session.** `tracker_get` with `fm:plan:<workspace-relative-path>`, then `tracker_link_session` with the returned id. Never create a second tracker item.

3. **Checklist.** Reuse an existing `## Implementation checklist` (or legacy `## Implementation Progress`); add missing deliverables to it. Otherwise create one under the intro: one `- [ ]` per phase, sub-items for deliverables. Don't otherwise restructure the plan.

4. **Frontmatter, before any code** (even if the checklist already existed): `status: in-development`, `startDate` if unset, `updated` to now (ISO), `progress` to the checked fraction.

5. **Implement, ticking as you go.** When a phase or deliverable lands, edit the plan in the same turn, before starting the next item: tick the box, set `progress` (checked / total boxes in the checklist, rounded) and `updated`. If you're about to say "Phase N passes" or "moving to Phase N+1" without having just edited the plan, edit it first. Never batch ticks to the end. Mirror the checklist with TaskCreate/TaskUpdate if available. On a blocker, set `status: blocked` and note why.

6. **Finish.** Check each box against what actually shipped; leave unfinished items unchecked and say why. Then `status: in-review`, `progress: 100`. Run typecheck; fix failing tests, never skip them.

• Apply the root `CLAUDE.md` feature-inventory rule and report the section updated or "No inventory impact" with a reason.
• Don't edit `CHANGELOG.md` (that happens at commit time via [/commit](./commit.md)) and don't commit unless asked.
• As a slice of a parallel batch, stay in your files and don't run the full gate; see [parallel-sessions.md](../rules/parallel-sessions.md).