mimimaster/piwin/subagent-driven-development

Subagent-Driven Development

Goal

Finish an approved plan by running isolatable steps in child sessions one writer at a time, then producing a correct parent state with verification evidence.

Done means

• A plan exists (/writing-plans or piwin_plan_create) with honest independentSteps (or fall back to executing-plans / inline).
• Each isolatable step runs in a child with a self-contained brief: step title/detail, plan goal, acceptance criteria, verification, and “implement only this step”. The child does not see the parent transcript.
• Parent reviews child diffs and verification output, applies approved candidates, updates steps via piwin_plan_set_step, and records failures instead of hiding them.
• Final parent verification passes (or failures are explicit).
• Bounded walkthrough summary exists: what changed, verification, child outcomes, unresolved items.

Stop when

• No safe independent steps — use inline execution.
• A child fails, merge conflicts, or verification fails — report and ask; do not silent-retry write children (new task + new child id if retrying).
• Parent would need to edit sources during delegated step execution — delegate instead.

Constraints

• Profiles from Settings bound capabilities; optional per-step profileId / model overrides cannot widen isolation.
• parallelGroup does not authorize concurrent worktree writes. Host runs at most one writer; use dependsOn for true sequencing.
• Readonly for explore/review (may run in parallel); worktree for writes (serialized). Shared-cwd parallel writes are rejected by the host.
• Host serializes worktree integration and retains failed/conflicted worktrees for inspection.
• Depth: children do not spawn further subagents via this path.

Verify

• Parent confirms merged tree against plan acceptance criteria (unit tests, typecheck, build as applicable).
• Walkthrough states only evidenced outcomes.