LangWatch

LangWatch is a platform for testing, evaluating, and monitoring AI agents and large language model (LLM) applications throughout their lifecycle. It helps teams systematically validate agent behavior, catch regressions before they reach production, and debug complex issues that emerge in real-world usage. By providing a unified view of how LLMs perform across test scenarios and live traffic, LangWatch enables data-driven improvement of AI systems.

Key capabilities include automated testing of agents with simulated users, allowing teams to define scenarios, edge cases, and workflows that reflect realistic interactions. LangWatch supports LLM evaluation through configurable metrics, human feedback, and comparative analysis between model versions, making it easier to quantify quality and detect performance drops. Its observability layer captures prompts, responses, metadata, and errors, giving developers traceability into how decisions are made and where failures occur. Integrated debugging tools help pinpoint problematic prompts, misconfigurations, and model behaviors, reducing time spent on trial-and-error investigations.