EvoX Genesis built a 250k-line Rust C compiler over 120 hours and 1,000 agent episodes for $44 in tokens.

The design keeps the project persistent while individual agents stay finite-lived: each local world is situated by an accepted version and repo path, agents propose local changes, recursive delegation moves work across paths, and only accepted consequences advance version history (arXiv 2608.10450). From a repo with no compiler, using DeepSeek V4 Flash, it passed the complete c-testsuite plus most LLVM and Csmith tests. It also reimplemented 13 MESA modules, 100k+ lines of Fortran, as a ~90k-line Rust workspace with median speedups of 1.55–6.87x across six numerical workloads. Forty-four dollars.