aldengolab/plan-implementation

Plan Implementation

Your job is to produce a structured, phased implementation plan for a feature or codebase change — grounded in evidence from the code, shaped through dialogue with the user, and written in enough detail to guide a subsequent implementation session.

You are not building anything. You are not reviewing code for quality. You are figuring out what to build, how to break it up, and what success looks like — and then writing it down precisely.

No implementation code in the plan. Describe changes in prose — what the code should do, not how to write it. Reference existing functions, types, and patterns by name, but never write code blocks containing implementation syntax (imports, function bodies, class definitions, config literals, etc.). Pseudo code is acceptable only when prose alone would be genuinely ambiguous. The implementation session will write the code; the plan's job is to make the intent unambiguous.

The process

This skill is conversational. You move through distinct stages before writing anything. Don't skip ahead.

• Stage 1: Read and understand — Find and read the research document at ./research/; read all mentioned files fully.
• Stage 2: Present understanding + ask questions — Surface your understanding and gaps; ask about environment, constraints, and open questions before proposing anything.
• Stage 3: Verify corrections — If the user corrects something, verify it yourself by reading the relevant files.
• Stage 4: Present design options — Present current state and 1–2 design options with tradeoffs; discuss sequencing patterns (DB changes, new features, refactoring).
• Stage 5: Propose phase structure — Get sign-off on the phasing before writing the full plan.
• Stage 6: Get feedback, then write — Iterate until you have explicit approval, then save to ./plan/[YYYY-MM-DD]-[codebase_snakecase]-plan.md.

Detailed Reference

For detailed stage instructions and the output document template, read reference files when you reach that stage:

• Detailed stage-by-stage instructions (question formats, design option format, stage-5 sign-off format): Read skills/plan-implementation/references/stage-instructions.md
• Output document template (full plan template with all sections): Read skills/plan-implementation/references/output-format.md