| name | spec-extract |
| description | Reverse-engineer a spec from existing code. Explores the codebase for a given area/feature and generates a spec that documents what's already implemented. Use to create specs for legacy code or to establish a baseline. |
| argument-hint | <area or feature name> |
Extract Spec from Code
Reverse-engineer a spec for $ARGUMENTS by reading the existing implementation.
Process
1. Explore
Use Explore agents to find all code related to $ARGUMENTS:
- Rust: types, functions, API endpoints, DB queries, tests
- Frontend: components, API calls, stores, pages
- Config: locale keys, CLAUDE.md references
2. Reconstruct
From the code, derive:
- What it does — summarize the feature from the implementation
- Acceptance Criteria — reverse-engineer testable ACs from what the code actually does (not what it should do)
- API Contract — extract actual Rust types and endpoint definitions
- Data Model — extract actual DB schema from migrations/storage code
- Edge Cases — find error handling, match arms, guard clauses → these are the handled edge cases
- Test Coverage — find existing tests, note what's tested vs what's not
3. Present + Refine
Show the user what you found:
- "Here's what the code does for $ARGUMENTS"
- "These ACs are covered by tests: ..."
- "These have no tests: ..."
- "I found these gaps/inconsistencies: ..."
Ask: "Should I save this as-is, or do you want to adjust the spec to include planned improvements?"
4. Save
Write to docs/specs/$0.md using the standard spec template. Set status based on test coverage:
status: verified — all ACs have passing testsstatus: partial — some ACs untestedstatus: draft — mostly untested
Mark ACs as [x] if code exists and tests pass, [ ] if untested.
Rules
- Document what IS, not what SHOULD BE — this is a snapshot of current state
- If the user wants to add planned improvements, add them as new
[ ] ACs and set status to partial
- Reuse existing types verbatim — copy the actual struct definitions, don't paraphrase
- Note any code smells or inconsistencies in a
## Notes section (but don't judge)
Context
!head -20 /home/user/amigo-downloader/CLAUDE.md
Existing specs (avoid duplicates):
!ls /home/user/amigo-downloader/docs/specs/*.md 2>/dev/null || echo "No specs yet"
