Glossary — AudD resources

Definitions of the AudD-specific terms that appear across the API, responses, and SDKs. Each entry is one concept; where an SDK uses a different name than the HTTP wire form, both are noted.

Standard endpoint

POST https://api.audd.io/. The default recognition method, for a short audio clip (file-size cap 10 MB). Returns a single best match, or result: null when nothing is recognized. Response time is under two seconds.

Enterprise endpoint

POST https://enterprise.audd.io/. For longer audio — full-length songs, short-form videos, podcasts, broadcasts, DJ sets — and files with multiple songs. It splits the file into chunks server-side and returns every recognized track. There is no practical file-size cap. Billing is metered per 12 seconds of audio processed, so always set limit during development.

Chunk

The unit the enterprise endpoint works in: each submitted file is treated as a sequence of 12-second audio chunks. The skip and every parameters control which chunks are fingerprinted, and billing is counted per chunk.

offset

In an enterprise response, offset is the position within the file you submitted of the start of the 12-second chunk that contains a match. It locates the chunk in the overall file.

start_offset / end_offset

In an enterprise response, these are positions in milliseconds within the 12-second chunk (not within the whole file) marking where the matched fragment starts and ends. Combine with the chunk’s offset to place a match in the full file.

timecode

The position within the matched song at the point the submitted clip aligns to — for example, 02:32 means the clip matched the part of the recording two minutes and thirty-two seconds in. It is a position in the reference track, not an offset into the user’s clip.

score

A confidence value (0–100) on each enterprise match indicating how strongly the chunk matched that track. Higher is a stronger match. Access to score requires a Startup plan or higher.

ISRC

International Standard Recording Code — the unique identifier of a sound recording. Returned as isrc on a match. Available on enterprise responses and for accounts on a Startup plan or higher.

UPC

Universal Product Code — the identifier of a release (the product the recording was published on). Returned as upc on a match. Like ISRC, it is available on enterprise responses and on a Startup plan or higher.

audio_id

The identifier of a track in your own custom catalog, returned on a custom-catalog match. On such matches artist and title may be null, since the catalog entry is yours to map; you track the audio_id → song relationship on your side.

song_link

A universal link to the recognized song’s page on lis.tn, returned as song_link (for example, https://lis.tn/Warriors). It resolves to a page that links out to the song across services.

lis.tn

AudD’s short-link domain for song pages. song_link values point here.

fingerprint / audio fingerprinting

The compact, content-derived signature AudD computes from audio to identify it. Recognition works by fingerprinting the submitted audio and matching the fingerprint against the database, rather than comparing raw audio.

public database

AudD’s catalog of commercially released music — about 160 million songs — that the standard and enterprise endpoints match against by default.

custom catalog

A private fingerprint database attached to your account. You upload your own tracks via POST https://api.audd.io/upload/ (special access required; email [email protected]), and later recognition calls can match against them. Matches against your catalog carry an audio_id.

return / returnMetadata

The request option that asks for extra per-provider metadata blocks on a match. On the HTTP API it is the return form field (comma-separated identifiers such as apple_music,spotify,deezer,musicbrainz); the SDKs expose it as returnMetadata (or the language’s idiomatic equivalent). Provider metadata is not available on the enterprise endpoint.

market

Request parameter that sets the country code used for Apple Music, iTunes, and Spotify results in the returned provider blocks. Defaults to us.

extras / model_extra

A map on each typed result and per-provider block exposing fields that the SDK does not surface as typed properties — additional fields outside the typed surface. Read beta or newly added response fields through extras (some SDKs name the accessor model_extra) without waiting for a typed property.

stream / radio_id

A stream is a continuous audio source (radio, livestream, broadcast) registered for ongoing recognition via the streams endpoints. Each stream is identified by a radio_id, an integer you choose to label it. A stream URL can be a direct stream URL (HLS, Icecast, m3u/m3u8) or a shortcut such as twitch:<channel>, youtube:<video_id>, or youtube-ch:<channel_id>.

callback URL

The URL AudD POSTs stream recognition results to, set with setCallbackUrl. Each callback is a JSON payload with the recognized song. A working callback URL that returns 200 OK must be configured for the account even if you only consume results via longpoll.

longpoll

GET https://api.audd.io/longpoll/ — an HTTP long-polling way to receive stream results without running a callback server or holding a static IP. A callback URL must still be configured first; longpoll may never return events for an account that has no callback URL set, even when songs are being recognized.

longpoll category

The subscription key a longpoll client subscribes to, passed as the category parameter. It comes from the longpoll_category field on a stream in the getStreams response. You can share a category with clients without exposing your API token.

the test token

The public token api_token=test. It works only on the standard endpoint — not enterprise, not streams — and is limited to 10 requests per day. Use it for hello-world snippets; get your own token at dashboard.audd.io.

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