mosoo

An open-source, API-first managed Agent runtime for application backends.
Run OpenAI Codex, Claude Agent SDK, OpenCode, and Pi behind one API, each Session in its own sandbox.

Try mosoo · Website · API Documentation · mosoo-agent-driver · mosoo-connector · mosoo-skills

Your application keeps its business logic, end-user authentication, and UI. mosoo runs the Agent: it executes each turn in an isolated sandbox, keeps the working directory and the native conversation between turns, stores input files and artifacts, streams events, and records usage. It is built on Cloudflare Workers, Durable Objects, D1, R2, and Containers.

How It Works

Project API key + harness/model + instructions + input + optional files
  -> create a durable Session (a Thread in the API) and run the first turn
  -> follow status and events, download artifacts
  -> optionally send follow-up input to the same Session

Model credentials belong to your Project: you bring your own provider key. On /api/v2 the configuration is inline or a saved Agent, a reusable preset (harness, model, instructions, Skills, MCP servers, Environment); /api/v1 takes only a published Agent and runs its live version. docs/SPEC.md is the product contract.

mosoo is in Alpha. Public APIs and product behavior may still change.

Getting Started

The fastest way to try mosoo is the hosted console at cloud.mosoo.ai. To run it locally you need bun >= 1.4.0-canary.1, just, and a Docker-compatible daemon for Agent sandboxes.

git clone --recurse-submodules https://github.com/langgenius/mosoo.git
cd mosoo
just setup   # dependencies, submodules, apps/api/.dev.vars, Git hooks, local D1
just dev     # console on http://localhost:5173, API on http://localhost:8787

From another terminal, curl http://localhost:8787/api/health returns {"name":"mosoo","ok":true}. CONTRIBUTING.md covers local sign-in, verification, and the commit policy.

Example: Build a Codex Agent API

Codex Pet integrates a mosoo Agent into an existing product backend through the Thread API.

Mosoo.Agent.as.API.mp4

Documentation

• API reference: mosoo.ai/docs
• Product contract: docs/SPEC.md
• Architecture and invariants: docs/architecture.md
• Product notes: docs/prd/README.md
• Production status: mosoo.ai/status

Contributing

Report bugs and request features in GitHub Issues. Read CONTRIBUTING.md before opening a pull request; CLA Assistant asks first-time contributors to sign the Contributor License Agreement.

License

mosoo is licensed under the Apache License 2.0.