Schema

Here’s the minimum data you need to submit a release. ONCE will fill in defaults for optional fields like label, pline_year, and pline_owner.

You can fetch the schema in two ways (no authentication required):

• get_release_schema tool
• resources/read for mcp://schemas/release-required

Most clients load this automatically after resources/list, but you can always call it directly if you need a fresh copy.

Release Fields

Track Fields

Validation Rules

• Single tracks: track.title must match release.title
• Writers: Each writer.name must be a full legal name (first + last)
• Explicit flag: Must be boolean true or false

Example Payload

{
  "release": {
    "title": "My Release",
    "primary_artist_name": "Artist Name",
    "genre": "Pop",
    "release_date": "2026-02-01",
    "cover_art_file_url": "/api/files/cover-art/USER_ID/cover.jpg"
  },
  "tracks": [
    {
      "title": "My Release",
      "primary_artist_name": "Artist Name",
      "audio_file_url": "/api/files/audio/USER_ID/track.wav",
      "explicit_flag": false,
      "writers": [{ "name": "First Last" }]
    }
  ]
}