v0.2.29 source analysis updated

Deconstructing Claude Code Source

Deep dive into the internals of Anthropic's official CLI tool. From architecture design and Agent loops to terminal rendering — a comprehensive analysis of 1,902+ files and 514k+ lines of TypeScript.

1,902+Source Files

514k+Lines of Code

35Core Modules

agent-loop.ts

1async function runAgentLoop(ctx: Context) {
while (true) {
  // 1. Gather context and tools
  const tools = await getAvailableTools(ctx);
  
  // 2. Call Claude API
  const response = await callClaude(ctx, tools);
  
  // 3. Handle tool calls or return result
  if (response.type === 'tool_calls') {
    await executeTools(ctx, response.calls);
  } else {
    return response.text;
  }
}
16}

Architecture

Core Module Breakdown

View full architecture

Ink UI components (~140 components)

389 Files81.9k LOC

services

External service integrations

130 Files53.8k LOC

tools

Agent tool implementations (~40 tools)

184 Files51.0k LOC

commands

Slash command implementations (~50 commands)

207 Files26.7k LOC

Deep Dives

Deep Dive Articles

Browse all articles

Architecture01

The Big Picture: How a 512,000-Line AI CLI Is Built

Starting from the leak, we take our first look inside Claude Code's massive codebase and build a complete mental model from the CLI entry point to the LLM engine

15 min read Deep dive

Core Mechanics02

The Query Engine: The Complete Lifecycle of a Conversation

Deep dive into QueryEngine.ts and query.ts, tracing the full journey of a conversation from user input to final response, and understanding the async-generator-driven streaming query loop

15 min read

Tool System03

The Tool System: How AI Safely Interacts with the Outside World

Deep dive into Claude Code's 40+ tool system — from type definitions to concurrent execution to the six-layer permission evaluation pipeline, understanding how AI safely operates on the external world

15 min read

Roadmap

Analysis Roadmap

Foundation & Startup

CLI entry, config loading, auth flow

Agent Core Loop

Prompt building, API interaction, tool scheduling

Tool Library

File operations, Bash execution, AST analysis

Terminal UI Rendering

Ink component tree, streaming output, interaction handling