Mouse, built on OpenCode, achieved first place on the FrontierHarness benchmark with a score of 25/30, up from OpenCode's last-place 15/30. The key improvement was a verification loop that enforces a fixed sequence of deterministic steps—checking git changes, running repo checks, verifying no tests were deleted, and validating a MOUSE_AUDIT file—allowing the agent to iteratively refine solutions until all requirements pass, achieving an impressive 90.6% cache hit rate.