Labels

Contrail can subscribe to AT Protocol labelers and attach their labels to records and profiles.

Configure

export default {
  namespace: "com.example",
  collections: {
    event: { collection: "community.lexicon.calendar.event" },
  },
  labels: {
    sources: [
      { did: "did:plc:ar7c4by46qjdydhdevvrndac" },
    ],
  },
};

Normal contrail backfill, Worker cron ingestion, and runPersistent() include configured labelers automatically.

Select labelers

A request chooses labelers with the standard header:

Atproto-Accept-Labelers: did:plc:ar7c4by46qjdydhdevvrndac

Use ?labelers=did:plc:... when setting a header is inconvenient. Without either, Contrail uses labels.defaults, or all configured sources when defaults are omitted. Set defaults: [] to require callers to opt in.

Selected labels appear as record.labels. Account labels appear on hydrated profile entries. The response’s Atproto-Content-Labelers header reports which configured labelers were applied.

Contrail drops expired labels, applies CID-pinned labels only to the matching record version, and treats newer neg: true labels as retractions.

Label signatures are stored but are not currently verified. Contrail consumes labels; it does not publish a label stream or provide moderation-preference UI.