Skills over MCP

fast-agent supports the draft SEP-2640: Skills over MCP Extension.

When a connected MCP server advertises this capability, fast-agent shows it as an MCP-backed skills registry. Opening /skills registry reads skill://index.json and lists installable skill-md or archive entries that include a valid sha256: digest. Installing a selected entry downloads the artifact, verifies its SHA-256, then writes the skill into the normal managed skills directory. Installed skills then behave like other local skills and include MCP server provenance plus the verified artifact digest in their sidecar metadata.

Trying it

Run or connect to a SEP-2640-enabled MCP server. This example uses the hosted Hugging Face MCP Server:

/mcp connect --name hf https://huggingface.co/mcp
/mcp
/skills registry
/skills registry hf
/skills available
/skills add <number|name>

/mcp shows when SEP-2640 Skills over MCP is enabled and points you to /skills registry to select the MCP server as the current install source. Listings show integrity: SHA256 checked for installable MCP skills.

Current scope

This implementation uses MCP as a registry for installation. It does not expose MCP-served skill resources directly to the model, and it does not make active skills read supporting files from the MCP server. That deeper resource-loading workflow is planned separately.

/skills update can compare the installed artifact digest with the current MCP registry digest and apply a verified update when the server publishes a newer artifact. The top-level fast-agent skills CLI remains marketplace/file/GitHub oriented; select MCP registries from an interactive session after connecting the MCP server.

Thanks to olaservo for contributing this feature.