AgentsKit.js is a composable TypeScript framework for building and deploying AI agents in JavaScript without stitching together multiple libraries. It provides a unified foundation covering runtime, tools, memory, RAG, model adapters, and headless UI bindings in a core package under 10KB with zero dependencies. Developers can swap model providers, UI surfaces, or memory backends without rewriting their agent logic. The ecosystem includes 50 built-in integrations, 140-plus model providers, and 22 ready-made agent packages, all released under the MIT license.