The Auto-Fix Loop

The auto-fix loop is the pattern where an agent writes code, runs tests or linters, observes failures, and iterates until all checks pass, distinguishing a coding agent from a one-shot code generator by having the agent validate and repair its own work through interaction with the real development environment. This tight write-run-fail-fix cycle works best when the success criteria are machine-verifiable, such as passing tests, clean types, and no lint errors, and breaks down when evaluation requires human judgment like architectural fit or code quality. The key failure mode to watch for is an agent that "fixes" a failing test by weakening the assertion rather than correcting the implementation, so reviewing what changed in the test files is as important as reviewing what changed in the source files.