Legion is an open-source Elixir runtime for AI agents created by Software Mansion that live directly inside your application and get things done by writing code. Instead of acting as a chatbot that only talks, Legion agents reach into your application to find records, run reports, change settings, or file tickets within boundaries you define.

Designed for Elixir developers, the library provides production essentials out of the box, including sandboxed execution with time, memory, and CPU limits, Postgres-backed persistence, and a live dashboard to inspect agent actions.

Use Cases

Developers powering an MCP server for Claude or Cursor
Engineers running background workers that clear queues overnight
Teams building chat interfaces backed by application-aware agents
Applications requiring automated code generation and execution within a sandboxed runtime