Frobs are external tool call integrations. They allow users to define external actions that can be executed by the LLM while researching the user's query.

Frobs are stored in $HOME/.fnord/tools/$frob_name and are composed of:

• registry.json: A JSON file that registers the frob for the user's projects
• spec.json: A JSON file that defines the tool call's calling semantics
• main: A script or binary that performs the action

The registry.json file contains the following fields:

{
  // When true, the frob is available to all projects and the "projects"
  // field is ignored.
  "global": true,

  // An array of project names for which fnord should make the frob
  // available. Superseded by the "global" field when set to true.
  "projects": ["my_project", "other_project"]
}

The "name" field in spec.json is used to register the frob with the LLM. This name must match the frob's directory name.

If desired, the user can add a lib/util/etc directory to hold any utility or helper code to be used by main.

Fnord communicates run-time information to the frob via environment variables:

• FNORD_PROJECT # The name of the currently selected project
• FNORD_CONFIG # JSON object of project config
• FNORD_ARGS_JSON # JSON object of LLM-provided arguments