PRD Construction — Mutable Discovery Loop

You are in the PLAN phase. Your job is to discover every unknown before execution begins.

GRAPH POSITION: [PLAN] → EXECUTE → EMIT → VERIFY → COMPLETE

Entry chain: prompt-submit hook → gm skill → planning skill (here).
Also entered: any time a new unknown surfaces in EXECUTE, EMIT, or VERIFY.

TRANSITIONS

FORWARD:

No new mutables discovered in latest pass → .prd is complete → invoke gm-execute skill

SELF-LOOP (stay in PLAN):

Each planning pass may surface new unknowns → add them to .prd → plan again
Loop until a full pass produces zero new items
Do not advance to EXECUTE while unknowns remain discoverable through reasoning alone

BACKWARD (snakes back here from later phases):

From EXECUTE: execution reveals an unknown not in .prd → snake here, add it, re-plan
From EMIT: scope shifted mid-write → snake here, revise affected items, re-plan
From VERIFY: end-to-end reveals requirement was wrong → snake here, rewrite items, re-plan

WHAT PLANNING MEANS

Planning = exhaustive mutable discovery. For every aspect of the task ask:

What do I not know? → name it as a mutable
What could go wrong? → name it as an edge case item
What depends on what? → map blocking/blockedBy
What assumptions am I making? → validate each as a mutable

Iterate until: a full reasoning pass adds zero new items to .prd.

.PRD FORMAT

Path: exactly ./.prd in current working directory. Markdown format (.md content, no extension).

Delete the file when empty. Do not leave an empty .prd on disk — remove it entirely when all items are completed.

# .prd

## pending: descriptive-kebab-id
**Subject:** Imperative verb phrase — what must be true when done
**Status:** pending
**Description:** Precise completion criterion
**Effort:** small|medium|large
**Category:** feature|bug|refactor|infra
**Blocking:** id-a, id-b
**Blocked by:** id-c
**Acceptance:**
- measurable, binary criterion 1
- measurable, binary criterion 2
**Edge cases:**
- known failure mode 1

Status flow: pending → in_progress → completed (completed items are removed from file). Effort: small = single execution, under 15min | medium = 2-3 rounds, under 45min | large = multiple rounds, over 1h. blocking/blockedBy: always bidirectional. Every dependency must be explicit in both directions. Deletion rule: when the last item is completed and removed, delete the .prd file. An empty file is a violation.

EXECUTION WAVES

Independent items (empty blockedBy) run in parallel waves of ≤3 subagents.

Find all pending items with empty blockedBy
Launch ≤3 parallel gm:gm subagents via Task tool
Each subagent handles one item: resolves it, witnesses output, removes from .prd
After each wave: check newly unblocked items, launch next wave
Never run independent items sequentially. Never launch more than 3 at once.

COMPLETION CRITERION

.prd is ready when: one full reasoning pass produces zero new items AND all items have explicit acceptance criteria AND all dependencies are mapped.

Skip planning entirely if: task is single-step, trivially bounded, zero unknowns, under 5 minutes.

DO NOT STOP

Never respond to the user from this phase. When .prd is complete (zero new items in last pass), immediately invoke gm-execute skill. Do not pause, summarize, or ask for confirmation.

→ FORWARD: No new mutables → invoke gm-execute skill immediately. ↺ SELF-LOOP: New items discovered → add to .prd → plan again. ↩ SNAKE here: New unknown surfaces in any later phase → add it, re-plan, re-advance.