POST userCollections/{id}/relationships/tracks returns GENERIC_REQUEST_ERROR - Bug Recurring (Jan 2026)

[jameson-lt]

Summary

The POST /v2/userCollections/{id}/relationships/tracks endpoint consistently returns a GENERIC_REQUEST_ERROR while the identical request format works correctly for albums and artists. This is a recurrence of the issue reported in #236.

Related Issues

• Resource POST `userCollections/{id}/relationships/tracks` returns `GENERIC_REQUEST_ERROR` #236 - Same bug reported in Sep 2025, temporarily fixed, now recurring

Environment

• API: https://openapi.tidal.com/v2
• OAuth Scopes: collection.read, collection.write, user.read
• Auth Method: Authorization Code + PKCE flow

Reproduction

All three requests use identical format - only the endpoint and type differ:

✅ Albums - Works (201 Created)

curl -X POST 'https://openapi.tidal.com/v2/userCollections/{userId}/relationships/albums' \
  -H 'Authorization: Bearer {access_token}' \
  -H 'Content-Type: application/vnd.api+json' \
  -H 'Accept: application/vnd.api+json' \
  -d '{"data":[{"id":"378149557","type":"albums"}]}'
# Response: HTTP 201 - Album added to collection ✅

✅ Artists - Works (201 Created)

curl -X POST 'https://openapi.tidal.com/v2/userCollections/{userId}/relationships/artists' \
  -H 'Authorization: Bearer {access_token}' \
  -H 'Content-Type: application/vnd.api+json' \
  -H 'Accept: application/vnd.api+json' \
  -d '{"data":[{"id":"7958797","type":"artists"}]}'
# Response: HTTP 201 - Artist followed ✅

❌ Tracks - Fails (400 Bad Request)

curl -X POST 'https://openapi.tidal.com/v2/userCollections/{userId}/relationships/tracks' \
  -H 'Authorization: Bearer {access_token}' \
  -H 'Content-Type: application/vnd.api+json' \
  -H 'Accept: application/vnd.api+json' \
  -d '{"data":[{"id":"378149573","type":"tracks"}]}'
# Response: HTTP 400
# {"errors":[{"code":"GENERIC_REQUEST_ERROR","detail":"Your request could not be processed due to invalid input. Please check your data and try again."}]}

Verified

• ✅ Track ID 378149573 exists and is valid (verified via GET /v2/tracks/378149573)
• ✅ Token has correct scopes (collection.write)
• ✅ User ID is correct (verified via GET /v2/users/me)
• ✅ Albums/Artists work with same request format
• ✅ GET /v2/userCollections/{userId}/relationships/tracks works (can read tracks)

Impact

This bug prevents third-party apps from adding tracks to user collections, which is a core use case for music automation tools.

Notes

Per #236 (closed), this bug was reported in September 2025, appeared to be fixed, but @kddlb reported it recurring on Dec 29, 2025. We are now experiencing the same issue as of January 2026.

Would appreciate any update on the status of this endpoint. Thank you!

[blackarcanis]

Hi!
It's happening to me right now, too, randomly on the artist/album endpoint while having the exact same well-formatted body.
Update: The error is now {"errors":[{"code":"GENERIC_REQUEST_ERROR","detail":"Your request could not be processed due to invalid input. Please check your data and try again."}]}