Grady Martin writes: A security researcher has leaked a complete repository of source code for Anthropic's flagship command-line tool. The file listing was exposed via a Node Package Manager (npm) mapping, with every target publicly accessible on a Cloudflare R2 storage bucket. There's been a number of discoveries as people continue to pore over the code. The DEV Community outlines some of the leak's most notable architectural elements and the key technical choices: Architecture Highlights The Tool System (~40 tools): Claude Code uses a plugin-like tool architecture. Each capability (file read, bash execution, web fetch, LSP integration) is a discrete, permission-gated tool. The base tool definition alone is 29,000 lines of TypeScript.The Query Engine (46K lines): This is the brain of the operation. It handles all LLM API calls, streaming, caching, and orchestration. It's by far the largest single module in the codebase.Multi-Agent Orchestration: Claude Code can spawn sub-agents (they call them "swarms") to handle complex, parallelizable tasks. Each agent runs in its own context with specific tool permissions.IDE Bridge System: A bidirectional communication layer connects IDE extensions (VS Code, JetBrains) to the CLI via JWT-authenticated channels. This is how the "Claude in your editor" experience works.Persistent Memory System: A file-based memory directory where Claude stores context about you, your project, and your preferences across sessions. Key Technical Decisions Worth Noting Bun over Node: They chose Bun as the JavaScript runtime, leveraging its dead code elimination for feature flags and its faster startup times.React for CLI: Using Ink (React for terminals) is bold. It means their terminal UI is component-based with state management, just like a web app.Zod v4 for validation: Schema validation is everywhere. Every tool input, every API response, every config file.~50 slash commands: From /commit to /review-pr to memory management -- there's a command system as rich as any IDE.Lazy-loaded modules: Heavy dependencies like OpenTelemetry and gRPC are lazy-loaded to keep startup fast.Read more of this story at Slashdot.