---
title: "Reference"
description: "Fields, error codes, payload shapes, and a glossary."
---

# Reference

Fields, error codes, payload shapes, and a glossary. Part of [AudD resources](https://audd.io/resources/index.md).

- [Apple Music metadata block](https://audd.io/resources/reference/apple-music.md): How to request and read the Apple Music metadata block on an AudD match: the track URL, AAC preview, artwork template, catalog ID, and ISRC.
- [Deezer metadata block](https://audd.io/resources/reference/deezer.md): How to request and read the Deezer metadata block on an AudD match: the Deezer track link, MP3 preview, album cover art, and numeric IDs.
- [Enterprise response and match fields](https://audd.io/resources/reference/enterprise-match-fields.md): The chunked response shape of the AudD enterprise endpoint (enterprise.audd.io): per-chunk offset, per-song score, ISRC/UPC, accurate offsets, and the request parameters that control chunking.
- [Error codes reference](https://audd.io/resources/reference/errors.md): Every AudD API error code, grouped by category, with the typed SDK exception family each maps to and whether it is safe to retry.
- [Glossary](https://audd.io/resources/reference/glossary.md): Concise definitions of AudD-specific terms an integrator or agent will encounter: endpoints, billing, result fields, identifiers, streams, request parameters, the CLI, and the MCP server.
- [Music rights and recognition glossary](https://audd.io/resources/reference/music-rights-glossary.md): Short, factual definitions of the music-industry and content-moderation terms that come up around music recognition: fingerprints and watermarks, recordings and compositions, ISRC, ISWC, UPC, PROs, license types, DDEX, notice-and-takedown, DMCA, Article 17, and the DSA.
- [MusicBrainz metadata block](https://audd.io/resources/reference/musicbrainz.md): How to request and read the MusicBrainz metadata block on an AudD match: an array of recordings with MBIDs, ISRCs, match scores, and expanded releases.
- [Napster metadata block (no longer available)](https://audd.io/resources/reference/napster.md): Napster metadata is no longer available from the AudD API: the platform ceased operations. What happens if you still request it, and what to use instead.
- [Provider metadata blocks (Apple Music, Spotify, Deezer, MusicBrainz)](https://audd.io/resources/reference/provider-metadata.md): How to request Apple Music, Spotify, Deezer, and MusicBrainz metadata on an AudD match, where each block's fields are documented, and when song_link is enough instead.
- [Recognition result fields](https://audd.io/resources/reference/result-fields.md): The fields of the result object returned by the standard AudD recognition endpoint (api.audd.io), including timecode, song_link, audio_id, and provider metadata blocks.
- [Spotify metadata block](https://audd.io/resources/reference/spotify.md): How to request and read the Spotify metadata block on an AudD match: the track URI and open.spotify.com URL, preview, album artwork, and IDs.
- [Stream callback and longpoll payload reference](https://audd.io/resources/reference/streams-callback-shape.md): The exact JSON your callback receiver and longpoll consumer get from AudD streams: result bodies, notification bodies, the getStreams list, and the longpoll keepalive.

## Sitemap

See the [resources sitemap](https://audd.io/resources/sitemap.md) for every guide and the [glossary](https://audd.io/resources/reference/glossary.md) for AudD terms.