name: build-phase description: "Build a specific phase by number. Spawns Builder to implement the approved phase plan. Phase 1 quality gates (PostToolUse, Stop hooks) fire automatically on Builder. Use when you're ready to implement an approved phase plan. Triggers on: '/build-phase', 'build phase', 'implement phase', 'start building phase', 'execute phase'." arguments: [phase_number] allowed-tools: [Read, Bash, "Task(Builder)"] metadata: version: "1.0.2"

Build Phase $phase_number

Live State

Plan files for phase $phase_number: !ls .tasks/*/plan/phase-${phase_number}-*.md 2>/dev/null

If no plan file is listed above, the phase number may be incorrect or no task has a plan for it.

What to do

1. Identify the task the plan file belongs to. In the Conductor's loop

(prime → plan → approve → build → review → accept → commit → check_phase) this is the build step: call prime first and follow its advice; the Worktree: path is where the Builder works.

1. If no plan file exists, report: "No plan found for phase

$phase_number. Run /plan-phase [task_slug] first to create a plan."

1. Spawn Builder to implement the plan:

• Use the Task tool to spawn a Builder subagent
• Instruct Builder: "Implement Phase $phase_number. Read the plan at

.tasks/[task_slug]/plan/phase-$phase_number-[name].md. Follow the plan's implementation steps exactly. Work in [the Worktree: path]."

• Builder's quality gates from Phase 1 fire automatically:

PostToolUse hook runs validation after each Edit/Write Stop hook blocks completion without validation evidence

• No manual validation needed — the hooks enforce it

1. After Builder completes, report the results. Do NOT mark the phase

as done: check_phase is the one progress writer, and the loop calls it after the commit — use /ship to commit the changes first.

Notes

• Quality gates: the global quality-gate hook (PostToolUse Bash +

Stop) records validation exit codes and blocks Stop when an edit happened after the last green run. The hook reads exit codes directly; no tag-prefix format.

• Access control: this skill never edits task files; phase progress

moves only through check_phase.