Plan

/plan — phased implementation plan

Goal: a plan an executor (you or a subagent) can follow without re-deriving context.

Do this

1. For non-trivial work, delegate to the harness-claude:planner agent, passing it the spec (read .claude/planning/<slug>/SPEC.md if present — the slug is in .claude/STATE.md), the reuse decision, and the objective/purpose (not just a one-line query).
2. For small/linear work, plan inline using the same shape.
3. Break work into phases/tasks: each small, independently verifiable, with an exit check. Give each task an ID (T1, T2, …), its write-set (files it will create/edit), a depends_on list of prior task IDs, and the AC-n criteria it addresses — the format /harness-claude:orchestrate and /harness-claude:verify consume (schema: docs/state-and-artifacts.md).
4. Surface risks, dependencies, and ordering explicitly. Red-team the plan before handing it off — assume it already failed and ask why; attack your own draft for hidden assumptions and missing edge cases, not just the obvious risks. Note where you'll need an architecture decision (/harness-claude:architect) vs. where the path is obvious.
5. Flag parallelizable phases. From the per-phase file lists, mark any phase that writes 3+ independent files with disjoint write-sets and no cross-dependency as an /harness-claude:orchestrate candidate. This is what makes /implement surface the parallel fan-out offer instead of silently editing serially — if you don't flag it here, it's usually missed there. Flag only genuine cases; if none qualify, say so.

Output

For non-trivial work, write .claude/planning/<slug>/PLAN.md (present a summary in the reply too); for trivial work, the plan in the reply is enough (say so). Format:

## Plan: <title>
## Tasks
### Task T1: <goal>
- files: <write-set>
- depends_on: []
- addresses: AC-1, AC-2
- exit check: <test/build/behavior>
### Task T2: ...
## Risks & dependencies
## Parallelizable phases (if any) — tasks with 3+ independent files, disjoint write-sets → /orchestrate candidates
## Where /architect is needed (if any)

State

When you wrote a PLAN.md, patch .claude/STATE.md: phase: plan, status: done, next_skill: /plan-check.

Orchestration note

This is the canonical sequential-phase flow (see rules/agents.md). Compact context before heavy implementation.

Exit criterion

Every task has a write-set, depends_on, the AC-n it addresses, and a concrete exit check. Then /harness-claude:plan-check (gate the plan before building) — or /harness-claude:architect first if flagged.