Hermes · Build a Plugin

Two files. That's a plugin.

A plugin is a folder in ~/.hermes/plugins/<name>/ with a tiny plugin.yaml manifest (name/version/description) and Python. The heart is a register(ctx) function; Hermes hands it a context object you use to wire things up. A tool is two halves: a schema (the JSON the model sees) and a handler (the Python that runs), connected with ctx.register_tool(...). In the same function, ctx.register_hook("post_tool_call", cb) adds a lifecycle hook. The context also registers slash commands, CLI subcommands, skills, and whole platforms. Plugins are opt-in: hermes plugins enable <name>, restart, then ask the model to use your tool and /plugins confirms it loaded.