version: "1.0.1" 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, Edit, Bash, "Task(Builder)"]

Build Phase $phase_number

Live State

!cat .tasks/*/state.json 2>/dev/null | jq -r '.task as $t | .phases[] | select(.id == ${phase_number}) | "Task: \($t) — Phase \(.id): \(.name) [\(.status)]"'

If no phase is shown above, the phase number may be incorrect or no task has that phase.

What to do

1. Read the injected state above — it shows the task and phase details

for phase $phase_number. Identify which task the phase belongs to.

1. Find the phase plan file:

• Look in .tasks/*/plan/phase-${phase_number}-*.md
• If no plan file exists, report: "No plan found for phase

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

1. Update state.json to mark the phase as in progress BEFORE spawning

Builder:

• If you have mcp__state-manager__* tools: use state_update to

set status to "in_progress", owner to "builder", and started to the current ISO-8601 timestamp

• Otherwise, use Edit on the task's state.json: set status to

"in_progress", owner to "builder", started to current timestamp

• PAV's scanner picks up this status change to show the phase as

"In Progress" on the kanban board with "Builder" as the current agent

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."

• 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 — use /ship to commit changes and update state.

PAV Integration

• Reads: state.json phase matching $phase_number — PAV's scanner

shows phase status and details on the kanban board (257 P3)

• Writes: status: "in_progress", owner: "builder", started

timestamp — PAV's scanner picks up these changes to display the phase as "In Progress" with "Builder" as the active agent

• 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. No tag-prefix format — the hook reads exit codes directly. PAV sees the gate via the registry and the task's validation entries in task.json.

• Invocation: PAV can invoke this command via socket steering or Agent

SDK to start building from its UI