Anthropic details how it used 16 parallel Claude Opus 4.6 agents to build a Rust-based 100,000-line C compiler, incurring ~$20K in API costs over 2,000 sessions (Anthropic)

Anthropic used 16 parallel Claude Opus 4.6 agents to build a Rust-based C compiler. The project involved 100,000 lines of code and incurred $20,000 in API costs over 2,000 sessions. This autonomous software development effort explored the future of agent teams in coding.