Version-level diff history showing what changed on a trademark and when
trademark_changes table for a single mark, reverse chronological by default. Each entry captures the fields that changed in one ingestion version, the old and new values, and the source data date. Use this when you need an audit trail of how a record evolved (status flips, owner changes, classification edits) rather than the office event timeline you get from /history.
tm_...).changed_fields array includes this field name (e.g. status_stage, owner_names, nice_classes).-changed_at (newest first, default) or changed_at (oldest first).created_at.created, updated, corrected).null for the initial version.| Status | Type | Description |
|---|---|---|
| 400 | validation_error | Invalid query parameter |
| 401 | unauthorized | Missing or invalid API key |
| 404 | not_found | Trademark ID does not exist |
| 429 | rate_limited | Too many requests |