Comparison
Codex vs Hermes Agent
How the two compare on the things that decide whether your setup carries over: open standards, license, models and where they run.
| Codex | Hermes Agent | |
|---|---|---|
| Maker | OpenAI | Nous Research |
| License | Apache-2.0 | Open source |
| Models | OpenAI models | Model-agnostic: hosted or local models |
| Runs in | Terminal, IDE, Desktop, Web | Terminal, Desktop, Messaging |
| MCP | MCP: supported | ?MCP: not yet verified |
| Agent Skills | Agent Skills: supported | Agent Skills: supported |
| AGENTS.md | AGENTS.md: supported | ?AGENTS.md: not yet verified |
| ACP | ACP: supported | ACP: supported |
Key differences
- Both are open source, so you can inspect and self-host either.
- Models: Codex runs OpenAI models; Hermes Agent runs Model-agnostic: hosted or local models.
- Codex also runs in IDE, Web; Hermes Agent also runs in Messaging.
- Codex supports MCP; we have not verified it for Hermes Agent.
- Codex supports AGENTS.md; we have not verified it for Hermes Agent.
- Both support Agent Skills, ACP, so MCP servers, skills and repo instructions you set up carry over if you switch.
In their own words
Codex
OpenAI's coding agent across CLI, IDE, ChatGPT and cloud. One of the originators of AGENTS.md, with Skills, MCP and a plugin marketplace.
Hermes Agent
Model-agnostic personal agent across CLI, desktop and messaging apps. Learns across sessions and writes reusable skills from its own work.
FAQ
- Is Codex or Hermes Agent open source?
- Codex is open source under Apache-2.0. Hermes Agent is open source.
- Do Codex and Hermes Agent support MCP servers?
- Codex: yes. Hermes Agent: not verified yet.
- Can I reuse Agent Skills between Codex and Hermes Agent?
- Yes. Both read the open Agent Skills (SKILL.md) format, so the same skill folder works in both.
Set up MCP servers in either one
More comparisons
Reviewed Oct 5, 2026.