LangChain Releases Better-Harness: Eval-Driven Self-Improving Agent Framework
The hardest part of building AI agents isn’t getting them to work. It’s getting them to keep working well as requirements change, edge cases accumulate, and the gap between “passed our tests” and “performs in production” widens. LangChain thinks they have an answer. On April 8, 2026, the company open-sourced Better-Harness — a framework that treats evaluation data not just as a scorecard but as a training signal, using hill-climbing to autonomously optimize agent performance over time. ...