Hermes Agent

Hermes Agent is an AI agent published by Nous Research, whose MCP client support ships as part of the standard install. Servers are configured as entries under mcp_servers in ~/.hermes/config.yaml, each carrying either a command plus args for a local stdio launch or a URL for a remote connection, and can also be added from a curated, Nous-reviewed catalog of 70 servers stored under optional-mcps/ in the repository; catalog entries are disabled by default and must be installed individually. The client implements stdio, Streamable HTTP and SSE transports, and its handler code supports tools, resources, prompts, sampling and elicitation, with sampling and elicitation enabled by default per server; roots is not documented anywhere in the client's transport or handler modules. A code comment in pyproject.toml states that the pinned mcp==2.0.0 SDK dependency "implements MCP revision 2026-07-28," which is evidence about that dependency rather than a Hermes-authored statement of the client's own supported revision, so spec status is recorded as unknown.

Hermes Agent also runs its own MCP server: hermes mcp serve exposes the agent's messaging conversations as MCP tools over stdio for other MCP clients, and Nous Research separately hosts a cloud-management MCP server at its portal, gated by OAuth, for administering Hermes Cloud deployments. CVE-2026-82021 covered a supply-chain flaw in the bundled catalog: the n8n entry under optional-mcps/n8n/manifest.yaml installed a third-party repository from a mutable main branch reference, and the manifest now pins a full commit SHA instead. As of 2026-09-15, the PyPI package hermes-agent was last published as version 0.19.0 on 2026-07-20, while the GitHub repository had moved on to release v0.21.3 (tag v2026.9.14) on 2026-09-14, leaving the published package several releases behind the source tree.