Anthropic released Claude Code as a competitor to Anysphere’s Cursor and Codium’s Windsurf. It uses LLM as an agent for software engineering tasks.

• Getting the Source Code: Download the npm package as a tarball and unzip it. The main control logic is in cli.mjs, which is obfuscated. The prettified source code is in a gist.

• Analysis:

  • System Prompt: Prompts are saved inside the code and stitched together during inference.
  • Language Specific Keyword Parsing: Sets up keyword and syntax parsing using regular expressions for OCAML.
  • Extension via Model Control Protocol (MCP): Allows extending functionality by providing tools via MCP servers.
  • Claude Code with AWS Bedrock: Supports AWS Bedrock and Google Vertex AI. Needs specific setup including creating an IAM policy and configuring environment variables.
  • Easter Egg: Allows getting Anthropic or Claude stickers by submitting a Google Form.
  • Trivia Factoids: Has an internal code name "tengu" and uses certain libraries.
  • Control Flow: A control flow diagram is provided, and the Mermaid code is in a gist.
• References: Links to Anthropic documentation, Model Control Protocol, and a Claude Code setup guide. There is also an article by Lee Hanchung with details about the exploration.