Referrers are the people credited with bringing a candidate into the pipeline — typically employees making referrals, but also agency recruiters, LinkedIn recruiters, or any other party captured under "Who Gets Credit" on a candidate's application. Each row is one referrer in the organization; resolve a referrer for an application by joining applications.referrer_id to this resource's id. A referrer is distinct from a Greenhouse user and from a source: user_id may link a referrer to a user when one exists but is often null, and the Referral source on an application tells you the channel while the referrer tells you the specific person credited. Filter to a single user's referrer records with user_ids. This endpoint is read-only; referrers are created and edited through the Greenhouse UI, not the Harvest API.