claude-code-2026-04-02/docs-site/docs/developer/navigating-the-source.md

Navigating the src/ tree

!!! warning "Read-only study" Use this guide to read the reconstruction. Do not treat the tree as a template for redistributing Anthropic’s product.

Suggested reading order

1. main argv and lifecycle — src/main.tsx (Commander, preAction, mode routing).
2. Interactive path — src/replLauncher.tsx, src/screens/REPL.tsx (queue, onQuery, UI).
3. Headless path — src/cli/print.ts, src/cli/structuredIO.ts, src/QueryEngine.ts.
4. Core loop — src/query.ts (queryLoop), then src/services/api/client.ts / claude.ts.
5. Tools — src/tools.ts, src/Tool.ts, then a single tool package e.g. src/tools/BashTool/ and src/services/tools/.
6. MCP — src/services/mcp/ and src/tools/MCPTool/.

Maps and indexes

• Top-level layout: Appendix: directory structure (and repo docs/directory-structure.md).
• Tool packages: Appendix: tool packages.
• Official doc crosswalk: Official docs map.

Search tips

From the repository root:

# Example: find where a symbol is used
rg "queryLoop" src/query.ts src/ -n

# Example: MCP channel permissions
rg "channelAllowlist" src/services/mcp -n

IDE “go to definition” may be incomplete: there is no root tsconfig.json or package.json mirroring Anthropic’s build, so path aliases like src/... might not resolve everywhere.

Deeper subsystems

Use the Reference section for per-topic entry points (permissions, compaction, telemetry, bridge, etc.).