Anthropic source code leaks reveal unannounced Claude features and internal model

Anthropic, the company behind Claude, has experienced two significant source code leaks in 2025 that reveal unannounced features and internal developments. The most recent leak exposed approximately 500,000 lines of code across nearly 2,000 files, which developers quickly mirrored and analyzed on GitHub.
What the leaks revealed
The leaked code contains several unannounced Claude features:
- KAIROS: A feature that allows Claude to run in the background and send push notifications
- Dream mode: Enables Claude to "think constantly in the background"
- Undercover Mode: Allows Claude to make "stealth contributions to open source projects"
- Capybara: An internal model that wasn't previously known to the public
Timeline and context
This is the second such leak in 2025, with the first occurring in February. The code was publicly accessible for hours before being taken down, during which time developers had already mirrored and dissected the content. The leaks come as Anthropic is reportedly preparing for an IPO as early as October 2025.
The incident raises questions about security practices at a company that positions itself as the "responsible AI company" with safety and ethics as core brand elements. The source material suggests this represents a gap between AI companies' public messaging and their internal operations.
📖 Read the full source: r/ClaudeAI
👀 See Also

Qwen 3 8B outperforms larger models in blind peer evaluations on hard tasks
In a blind peer evaluation of 10 small language models on 13 hard frontier-level tasks, Qwen 3 8B won 6 evaluations and placed in the top 3 in 12 of 13 tasks, outperforming models with up to 4x its parameter count. The evaluation covered distributed lock debugging, Go concurrency bugs, SQL optimization, Bayesian medical diagnosis, Simpson's Paradox, Arrow's voting theorem, and survivorship bias analysis.

GitHub Claude-Code v2.1.27 Release: Key Updates and Fixes
Claude-Code v2.1.27 enhances logging and fixes several issues, including context management and OAuth token expiration in VSCode.

Anthropic-xAI Compute Deal: Beyond Claude Code Limits
Anthropic signed a 300MW / 220k GPU compute deal with competitor xAI. This signals tighter GPU supply and structural cross-lab compute sharing, with implications for inference pricing and multi-provider routing.

Claude Desktop v1.1.5749 Adds Computer Control and Corporate Proxy Fixes
Claude Desktop v1.1.5749 introduces computer use capability with MCP server for desktop control, adds six macOS TCC permission management methods, and fixes corporate proxy SSL certificate issues by forwarding NODE_EXTRA_CA_CERTS, SSL_CERT_FILE, and SSL_CERT_DIR environment variables.