development-plan-doc-pro

# Development Plan Document PRO Use this skill when the user wants AI to investigate first and then produce a detailed implementation plan before coding. Goal: create a plan detailed enough that another engineer or agent can implement it without rediscovering the same context. ## Required research phase Before writing the plan, inspect the repository and identify: 1. Entry points and user-facing flow 2. Relevant modules, services, hooks, components, commands, or scripts 3. Existing types, interfaces, schemas, events, and configuration 4. Similar implementations to reuse 5. Data flow and state ownership 6. Test, build, and runtime validation paths 7. Security, compatibility, migration, and rollback risks Separate confirmed facts from assumptions. If a key detail cannot be found, mark it as an open question instead of inventing it. ## Plan structure Use this structure unless the user requests another format: 1. Goal and non-goals 2. Current-state findings 3. Proposed architecture 4. Data model and type definitions 5. Module-by-module implementation plan 6. Function/method/interface changes 7. Event, telemetry, or persistence changes 8. Validation plan 9. Rollout, rollback, and migration notes 10. Risks and open questions 11. Step-by-step task checklist ## Detail requirements - Name concrete files or modules when known. - Include proposed function names, signatures, type shapes, or config keys when useful. - Explain where data enters, how it transforms, and where it is persisted or rendered. - Include error handling, idempotency, permissions, and observability where relevant. - Provide validation commands or manual checks. - Keep speculative pieces clearly labeled. ## Final checks - Could another agent implement from this plan without redoing all research? - Are function/type/interface definitions specific enough? - Are risks, validation, and rollback included? - Are unknowns explicit rather than hidden?