Maps and documents codebases of any size by orchestrating parallel subagents. Creates docs/CODEBASE_MAP.md with architecture, file purposes, dependencies, and navigation guides. Generates docs/.mercator.json merkle manifest for O(1) change detection. Updates CLAUDE.md with a summary. Use when user says "map this codebase", "mercator", "/mercator-ai", "create codebase map", "document the architecture", "understand this codebase", or when onboarding to a new project. Uses merkle tree for O(1) change detection — only re-explores changed files.
2026-02-23