The entire source code for Anthropic’s Claude Code CLI has leaked due to an internal error during a package release. This includes nearly 2,000 TypeScript files and over 512,000 lines of code, exposing the application’s inner workings to competitors and developers. Anthropic has acknowledged the mistake and stated it was not a security breach.

• A packaging error in Claude Code v2.1.88 exposed a source map, leaking the entire ~2,000-file, 512,000+ line TypeScript codebase.
• The leaked code was quickly archived and uploaded to GitHub, gaining tens of thousands of forks within a short time.
• Anthropic says no customer data was exposed and calls it human error, not a security breach, while adding safeguards.
• Developers have already begun reverse-engineering internals, like Claude Code's memory architecture and background memory rewriting system.