Kiln-AI/harness-tuner: An agentic optimization loop for Kiln tasks

Harness Tuner is an open-source, agentic optimization loop designed for Kiln tasks that tunes prompts, tools, models, and settings rather than just prompts alone. Running on coding agents like Claude Code, Codex, or OpenCode, it uses enforced train, validation, and test data splits to improve agent performance while preventing regression and controlling costs. Open article →