Create a Plan Skill

This skill runs a structured technical interview to turn a rough idea or an existing spec into a detailed, implementable plan. The output is organized for parallel execution: foundations first, then independent workstreams, then merge and integration.

Invocation

The user will provide one of:

• A path to a spec or plan file (for example: SPEC.md, PLAN.md, RFC.md)
• A rough description of what they want to build
• A feature request or problem statement

Output is always written to PLAN.md in the repo root.

Process

Phase 0: Preflight

1. If a file path is provided, read it first and note goals, non-goals, constraints, and gaps.
2. Confirm you will produce PLAN.md as the output in the repo root. If PLAN.md already exists, update it rather than creating a new file.