Execute open tasks from specs/{feature}/plan.md using an implement → self-validate → fix loop, updating plan.md progress after each completed task. Use this skill whenever someone wants to start or continue feature implementation guided by plan.md, run a self-validating coding loop, continue from a specific task ID, or work through phased tasks with built-in quality checks. This is the execution phase after spec-plan in the spec-driven workflow. Don't use for ad-hoc bug fixes, code review, or implementation tasks not defined in plan.md.
Implement using specs/{feature}/plan.md as the single progress source.
Iron Law: No completion claims without fresh verification evidence. If you haven't run the command in this step, you cannot claim it passes.
specs/constitution.md when presentspecs/{feature}/spec.md and specs/{feature}/plan.mdspecs/{feature}/plan.md (and spec.md if findings require it)language and shared rules from specs/constitution.md when present; otherwise infer from workflow documents and the user's message. Ask only if still unclear.approved before work begins.plan.md to in-progress when work starts.local-only (continue), plan-impacting (update plan, realign), spec-impacting (stop, return upstream)spec-research when neededplan.md after each successful task:
status: in-progress until all tasks and phase DoD items finish## Progress Log (create if missing):
plan-impacting: update plan.md, realign before resumingspec-impacting: update spec.md, reset to draft, stop until re-approvedplan.md to done when all tasks and DoD items pass.spec-implement or final completion report.plan.md progress matches actual implementation statespec-implement or close implementation