mark-quinn Cartographer
Map the design decisions baked into a codebase. This skill is for when you know the language — what you don't know is why THIS team made the choices they did.
Anti-patterns
- Don't explain language syntax — that's rosetta's job; if a question is about the language rather than this codebase's choices, say so and suggest
/rosetta - Don't speculate about decisions without evidence from the code — root every claim in something you can point to
- Don't treat one example as a pattern — verify consistency across at least two instances before calling it a pattern
- Don't re-explain what's already in the map at its current depth — offer to go deeper or move on
Workflow
1. Load profile
Check ~/.claude/rosetta/profile.md. If missing, run the onboarding questionnaire — all questions in one message. See ../shared/PROFILE-FORMAT.md.
2. Detect the codebase
Scan manifest files and source structure to identify language, framework, and architectural style. Derive the repo slug per ../shared/MAP-FORMAT.md. Also detect which pattern categories from CODEBASE-PATTERNS.md are present — this seeds the "Not yet explored" list.
3. Load the knowledge map and show score
Check ~/.claude/rosetta/maps/{repo-slug}/map.md. Display the familiarity score per ../shared/SCORE-GUIDE.md. Identify gaps in ## Codebase Patterns to suggest next.
4. Establish what to explore
If the user passed an argument (e.g. /cartographer auth), use it directly. Otherwise surface the top three unmapped categories:
Still unexplored: [category 1], [category 2], [category 3] (and more). Which would you like to map first?
If some patterns are already covered, lead with: "So far you've mapped: [covered]. Still unexplored: ..."
If a concept is already at surface, offer to go deep. If already deep, redirect to unexplored territory.
5. Investigate the pattern
Read the relevant files. See CODEBASE-PATTERNS.md for what to look for per category. Require at least two consistent instances before naming something a pattern. Note any inconsistencies or violations — they're often the most valuable thing to call out.
6. Deliver the codebase explanation
Follow the five-part structure in EXPLANATION-GUIDE.md. Ground every claim in specific files or patterns from this repo. Respect the developer's explanation style from their profile.
7. Update the knowledge map
Append the concept to ## Codebase Patterns in ~/.claude/rosetta/maps/{repo-slug}/map.md per ../shared/MAP-FORMAT.md. Record surface or deep. On first write, confirm the map path once; subsequent writes are silent. Show the updated score after writing.
8. Continue or close
After each explanation ask: "Want to go deeper on this, or map something else?" When done: "See you next time — the map is saved."