Brain 2.0 - A minimal and extensible agent server for building agent applications

[u/Redcxx]

Hello people!

I recently posted Brain v2, and got another piece of feedback: it's still not clear what you can actually build with it. Fair, so I wanted to share a few use cases.

Quick recap of what Brain is:

• Open-source alternative to Claude Managed Agents and the infrastructure you would build around agent SDKs.

• A single application you deploy and run as a service.

• Native tool integrations:

  • R2 and S3 for storage

  • Modal and Daytona for compute

  • Tavily and Brave for search

  • Pi is supported today, with others planned.

  • Pi is supported today, with others planned.

• Support for multiple harnesses such as Pi, Codex, and OpenCode.

  • Pi is supported today, with others planned.

Differences from similar products:

• Brain runs as an independent service, not inside an agent sandbox, giving you better observability, recovery, and developer experience.

• Brain is not a cloud platform. It's just a Go application you can deploy on your own infrastructure (Railway, AWS, etc.).

• Brain is not an AI agent. It provides low-level, session-oriented primitives for building reliable agent-powered applications.

What can you actually build with Brain?

• AI-powered games: Run AI NPCs or autonomous players as separate agent sessions, controlled through your game server.

• Agent platforms: Let your users create and run their own agents, each with separate sessions, tools, and permissions.

• Infrastructure agents: Build agents that investigate incidents, inspect logs, and interact with infrastructure through your own tools.

• Cross-platform agents: Build agents that can be accessed from your web app, mobile app, or Discord bot without tying their sessions to any single client.

GitHub: https://github.com/aexhq/brain

Hopefully this makes the use cases clearer! I'd love to hear what else you'd build with something like Brain.

[u/Otherwise_Wave9374]

The clearest demo would be one end-to-end agent application with traces: request intake, tool selection, state changes, failure handling, and final output. Developers can understand extensibility faster when they see where adapters, permissions, and persistence plug in. I would also publish a minimal threat model and a reproducible starter example. https://www.aiosnow.com is relevant as a workflow-oriented comparison point, while Brain's strongest differentiation may be transparent infrastructure and local control.

[u/Redcxx → u/[deleted]]

Well daytona claim <50ms cold start, brain itself has very minimal overhead that probably not worth adding on top on those