#1717th of 42 in Agent and MCP starters
exo
Runtime that hosts Codex, Claude Code or Pi agents behind an API
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- Stars
- 1.6k
- License
- MIT
- Last commit
- Oct 2026
- Language
- Rust
11 on 22 May 20261,559 on 30 Oct 2026
From GitHub's daily star counts.
Checked on GitHub.
Overview
Exo is a Rust runtime that turns a markdown agent definition into a hosted agent with durable conversations, sandboxes, a credential vault and network policies. It separates harness behavior (compaction, tool calling, planning) from infrastructure, and supports Codex, Claude Code and Pi out of the box. It is positioned as a self-hostable alternative to Claude Managed Agents and OpenAI's Agents API.
Who it is for: Engineers self-hosting custom agents on top of existing coding harnesses
Strengths
- Agent defined in one markdown file with harness, model and credential fields
- Harness and model agnostic: Codex, Claude Code and Pi supported, custom harnesses extendable
- Credential substitution and granular network policies for unsupervised agent runs
- Durable history and environments let clients disconnect and resume
Weaknesses
- README says docs are under construction and some documented features are unimplemented
- Installation instructions not written; only a development setup from the repo
- No tagged release yet
- Exo-side code models Codex and Claude Code event lifecycles, adding complexity
What it needs
- Rust, Codex harness, Claude Code harness, Pi harness, OpenAI
- Needs Model provider API key (e.g. OPENAI_API_KEY)
- env example file
Quick answers
Is exo open source?
Yes. Its code is on GitHub under the MIT license.
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