Claude’s code: Anthropic leaks source code for AI software engineering tool

Nearly 2,000 internal files were briefly leaked after ‘human error’, raising fresh security questions at the AI company

Anthropic accidentally released part of the internal source code for its https://www.theguardian.com/technology/artificialintelligenceai">AI-powered coding assistant, Claude Code, due to “human error”, the company said on Tuesday.

An internal-use file mistakenly included in a software update pointed to an archive containing nearly 2,000 files and 500,000 lines of code, which were quickly copied to developer platform GitHub.

A post on X sharing a link to the leaked code had more than 29m views early on Wednesday, and a rewritten version of the source code quickly became GitHub’s fastest-ever downloaded repository.

Anthropic issued https://www.pcmag.com/news/anthropic-issues-8000-copyright-takedowns-to-scrub-claude-code-leak">copyright takedown requests to try to contain the code’s spread.

Within the code, users spotted blueprints for a Tamagotchi-esque coding assistant and an always-on https://www.theguardian.com/technology/ng-interactive/2026/mar/12/lab-test-mounting-concern-over-rogue-ai-agents-artificial-intelligence">AI agent, per https://www.theverge.com/ai-artificial-intelligence/904776/anthropic-claude-source-code-leak">the Verge.