Demorphus API

Version 1 · updated 2026-10-28 · Français

The API does exactly what the Studio does, from your own code: you send a track, Demorphus processes it and checks it with SH Labs, then you fetch the MP3. Same pipeline, same allowance, same result.

1. Who can use it

• Subscribers on Monthly (19 € / month, 50 tracks a month) and Yearly (60 € / year, 150 tracks a month).
• Accounts holding pay-as-you-go tracks (1.49 € a track).

The allowance is shared with the Studio: a track sent through the API counts like a track imported in the Studio. The free account has no API access.

2. Create a key

Sign in, open API access in the Studio, name the key and click “Create an API key”.

• The key starts with dmk_live_. It is shown only once: copy it right away. Demorphus keeps only a fingerprint and cannot show it again.
• At most 5 live keys per account. A key is revoked from the same page, immediately.
• Keep it on your server. Never put it in a web page or a mobile app.

3. Authentication

API base URL: https://studio.demorphus.com/api/v1

Every request sends the key in the header Authorization: Bearer dmk_live_…. No cookie is read.

curl -H "Authorization: Bearer $DEMORPHUS_KEY" https://studio.demorphus.com/api/v1/me

4. Process a track

A track takes 10 to 15 minutes, so the API is asynchronous: you send the file, get an id back, then ask for the track until it is ready.

Send the file

curl -H "Authorization: Bearer $DEMORPHUS_KEY" \
     -H "Idempotency-Key: $(uuidgen)" \
     -F [email protected] https://studio.demorphus.com/api/v1/tracks

Response 202, with a Location header pointing at the track:

{"reused": false, "track": {"id": "8f0c…", "status": "queued", "audio_url": null, …}}

The optional Idempotency-Key header is recommended. If the connection drops and you resend the same file with the same value, you get the same track back (200, "reused": true) without it being counted twice. One value per upload: 1 to 64 characters among A-Z a-z 0-9 _ . : -. Reused with another file, or more than 24 hours later, it answers 409.

Follow the track

curl -H "Authorization: Bearer $DEMORPHUS_KEY" https://studio.demorphus.com/api/v1/tracks/$ID

Ask every 30 to 60 seconds. The status field is one of:

The track also carries the same information as the Studio report: scores before and after (baseline, attempts), duration, SHA-256 fingerprints of the source and result files, expiry date.

Download the MP3

curl -H "Authorization: Bearer $DEMORPHUS_KEY" -o song-demorphus.mp3 \
     https://studio.demorphus.com/api/v1/tracks/$ID/audio

Available when status is done, not_reached or unverified (the audio_url field is then set). Files are erased after 7 days, as in the Studio.

5. Endpoints

6. Accepted files and limits

• MP3, WAV or FLAC, mono or stereo, 5 seconds to 10 minutes, under 50 MB.
• 10 uploads per minute per key.
• One track processed at a time per account. When 5 tracks are already waiting or under way across the whole service, an upload answers 429. Retry after the delay given in Retry-After.

7. Errors

Every error returns {"error": "…", "code": "…"} : error is a readable message, code never changes and is what your code should branch on.

402 quota_exhausted : the month’s allowance is used up and no pay-as-you-go track is left. It resets on the first of next month, or buy pay-as-you-go tracks from My account.

A question about the API? [email protected]