I Built Postman for AI Agents — Local, Free, and Open Source

I’ve been experimenting with and building AI agents for production systems for several years now. In that time, I’ve shipped prompt pipelines that power customer-facing features, debugged agents that silently hallucinated tool arguments, watched a model upgrade quietly regress behavior nobody caught for two weeks, and spent hours than I’d like to admit in each of the provider playgrounds. At some point, I started asking myself: why is this so inefficient? The ecosystem around LLMs and Agents has been evolving rapidly.