Thin Plan

Thin Plan

Purpose

Convert the mini-spec into 3-7 vertical implementation slices.

When to use

Use when SPEC.md exists and implementation needs a short, ordered path.

Inputs

• SPEC.md
• CONTEXT.md
• Existing repo structure
• Available verification commands

Workflow

1. If SPEC.md has an active Contract ID, copy that ID exactly into PLAN.md. Do not invent an ID when SPEC has none.
2. Identify the smallest end-to-end behavior.
3. Create 3-7 slices that each produce observable behavior.
4. Make every slice independently verifiable.
5. Keep each slice to the fewest files possible.
6. Avoid horizontal architecture-only tasks unless required.
7. Record dependencies, risks, and verification strategy.
8. Write PLAN.md and TODO.md.

Outputs

• PLAN.md
• TODO.md
• Active Contract ID in PLAN.md only when SPEC opted into contract identity

Stop conditions

• Each task has a visible result and a check.
• Planning reveals a missing spec decision.

Anti-patterns

• Planning all backend, then all frontend, then all tests.
• Creating broad tasks that cannot be finished in one session.
• Treating setup work as progress when no behavior changes.
• Inventing contract identity for work whose SPEC did not opt in.