I used Claude Code to understand the source code of Claude Code:<p><pre><code> 1. Tool-Based Action Framework
- Tools implement a common interface (Tool.ts) with standard methods
- Central registry in tools.ts manages tool availability and permissions
- Tools are categorized as read-only or stateful, affecting execution strategy
2. Agent Orchestration
- query.ts serves as the orchestration engine that:
- Identifies tool use requests in Claude's responses
- Manages permissions and serializes/deserializes tool data
- Schedules concurrent or serial tool execution based on tool type
- Feeds tool results back to Claude in a recursive loop
3. AgentTool Implementation
- Enables recursive agent capabilities via sub-agent spawning
- Sub-agents run with controlled permissions (typically read-only)
- Each agent invocation is stateless and returns a single result
- Implements progress streaming via async generators
4. Execution Flow
- User query → Claude response → Tool use requests → Permission checks
- Tool execution → Results normalized → Results fed back to Claude
- Process repeats with Claude potentially using additional tools
5. Architectural Patterns
- Async generators for streaming results and maintaining responsiveness
- Hierarchical permission model controlling tool access
- Normalized message formats ensuring consistent communication
- Logging chains for tracking agent activities
- Context management with optional compression (/compact)</code></pre>