Amid a push toward AI agents, with each Anthropic and OpenAI shipping multi-agent tools this week, Anthropic is greater than ready to indicate off a few of its more daring AI coding experiments. But as usual with claims of AI-related achievement, you’ll find some key caveats ahead.
On Thursday, Anthropic researcher Nicholas Carlini published a blog post describing how he set 16 instances of the corporate’s Claude Opus 4.6 AI model loose on a shared codebase with minimal supervision, tasking them with constructing a C compiler from scratch.
Over two weeks and nearly 2,000 Claude Code sessions costing about $20,000 in API fees, the AI model agents reportedly produced a 100,000-line Rust-based compiler able to constructing a bootable Linux 6.9 kernel on x86, ARM, and RISC-V architectures.
Carlini, a research scientist on Anthropic’s Safeguards team who previously spent seven years at Google Brain and DeepMind, used a brand new feature launched with Claude Opus 4.6 called “agent teams.” In practice, each Claude instance ran inside its own Docker container, cloning a shared Git repository, claiming tasks by writing lock files, then pushing accomplished code back upstream. No orchestration agent directed traffic. Each instance independently identified whatever problem seemed most evident to work on next and began solving it. When merge conflicts arose, the AI model instances resolved them on their very own.
The resulting compiler, which Anthropic has released on GitHub, can compile a variety of major open source projects, including PostgreSQL, SQLite, Redis, FFmpeg, and QEMU. It achieved a 99 percent pass rate on the GCC torture test suite and, in what Carlini called “the developer’s ultimate litmus test,” compiled and ran Doom.
It’s price noting that a C compiler is a near-ideal task for semi-autonomous AI model coding: The specification is a long time old and well-defined, comprehensive test suites exist already, and there’s a known-good reference compiler to ascertain against. Most real-world software projects have none of those benefits. The hard a part of most development isn’t writing code that passes tests; it’s determining what the tests must be in the primary place.
