Agent Express

About

Agent Express is an open source TypeScript framework for creating AI agents, structured as middleware. Developers familiar with Express.js middleware will find the process of building agents very similar. An agent's model-tool-model loop mirrors the request-response pattern of a web server, where a context passes through a series of composable functions using (ctx, next). Its architecture is based on three core concepts: Agent, Session, and Middleware, and it provides five hooks. The framework includes ready-made middlewares for features like budget monitoring, safety guardrails, system observability, memory optimization, and more.