Codebase Context Map

Overview

Maintain a rolling CODEBASE_CONTEXT.md at the project root: a token-efficient map of every module, key symbol, and architectural decision. Read it before searching; update it after large changes.

Two Modes

Mode A - Update (trigger: just finished a large plan touching 3+ files)

1. Glob all source files
2. For each module: read symbols overview, extract purpose + key classes/functions
3. Write/overwrite CODEBASE_CONTEXT.md using the template below

Mode B - Lookup (trigger: need to find where something lives)

1. Read CODEBASE_CONTEXT.md first
2. Found the answer? Use it. Done.
3. Not found? Grep/glob for specifics, then add the missing entry to the map.

Token savings: One 200-line context file = ~1,500 tokens. A grep+read cycle = 3,000-8,000 tokens per query. Break even after 1 lookup per session.