Cannot connect to the new Spotify app

[adam-kosik]

Hi @AnshulJ999,

Today I had to create a new Spotify Developer app that complies with the updated Spotify API rules (effective from Feb 11).
Unfortunately, I can no longer connect Spotify with SyncLyrics. Everything is configured as before — I updated the Spotify client ID and secret in docker-compose.yml, and the callback URL (https://192.168.0.168:9013/callback) is correctly set in the Spotify Developer app.
However, the connection keeps failing.
I’ve tested it across multiple devices and browsers.

An idea what's going on?

[AnshulJ999]

Hey @adam-kosik !

I'm not really sure what the issue here is; and unsure if it's related to Spotify's recent API changes.

As you said you've confirmed all ENV variables and that the Redirect URI matches in SyncLyrics and in Spotify Dashboard, could you please try docker compose down and docker compose up again to destroy and recreate the container? As someone else had another issue where the ENV variables didn't update without recreating it.

Personally I'm just waiting to see when my Spotify apps stop working and then I'll check if I have any issues too haha. But I will check if the recent changes affect the OAuth Scopes or anything else in this app.

Please let me know if recreating the container helps. Else, please attach some of the debug logs so I can investigate further.

Thanks!

[adam-kosik]

Hi @AnshulJ999,
Nope. Nothing helps.
docker compose down -> docker compose up -d triggered several times.

I also tried multiple browsers / devices.
No idea...

[AnshulJ999]

Hey @adam-kosik !

Thanks for confirming. And sorry to hear you're still facing this issue; so is the app completely unusable for you right now, or are you able to use it with Music Assistant or anything else?

If you could please attach some debug logs from the sessions where you failed to login, that would be helpful.

I'll check if I am able to create a new app for testing, though from what I understand, Spotify will allow existing developers to retain all 5 apps. If that's so, my quota is already filled haha. Still, I'm not sure how well the Spotify integration is going to continue if they make it this hard for all new users...

[AnshulJ999]

Hey @adam-kosik,

One more thing, please test the new v2.1.0-beta:

docker pull ghcr.io/anshulj999/synclyrics:2.1.0-beta

Even if it doesn't work, I did make some logging improvements that might help clarify what the exact issue is with Spotify authentication.

So please share the logs from this version.

Thanks!

[adam-kosik]

Hi @AnshulJ999,

Yes, Music Assistant works fine.

Here are logs from 2.1.0-beta

============================================
  SyncLyrics Docker Container Starting
============================================
Configuration:
  Server Port: 9012
  Debug: false
  Log Level: INFO
  Spotify Client ID: 7cf0c211...
  Spotify Redirect URI: https://192.168.0.168:9013/callback
  Polling Fast Interval: 2.0s
  Polling Slow Interval: 6.0s
  Data Directory: /data
Optional APIs configured:
============================================
(logging_config.py:191) INFO - Logging initialized - Console: INFO
(logging_config.py:192) INFO - Info Log file: /data/logs/synclyrics.log
(sync_lyrics.py:839) INFO - Starting SyncLyrics v2.1.0-beta...
(sync_lyrics.py:606) INFO - Starting server on port 9012...
(network_utils.py:49) INFO - Registering mDNS service: http://synclyrics.local:9012
(sync_lyrics.py:521) INFO - HTTP server starting on 0.0.0.0:9012
(sync_lyrics.py:534) INFO - HTTPS server starting on 0.0.0.0:9013
[2026-03-01 22:19:49 +0000] [1] [INFO] Running on http://0.0.0.0:9012 (CTRL + C to quit)
(logging.py:107) INFO - Running on http://0.0.0.0:9012 (CTRL + C to quit)
(logging.py:107) INFO - Running on https://0.0.0.0:9013 (CTRL + C to quit)
[2026-03-01 22:19:49 +0000] [1] [INFO] Running on https://0.0.0.0:9013 (CTRL + C to quit)
(network_utils.py:68) INFO - mDNS registration successful
(sync_lyrics.py:622) INFO - System tray disabled (headless mode or missing dependency).
(sync_lyrics.py:693) INFO - Entering main loop...
(spotify_api.py:442) INFO - Using persistent Spotify cache: /data/.spotify_cache
(spotify_api.py:480) ERROR - Failed to initialize Spotify API: error: invalid_client, error_description: Invalid client
(spotify_api.py:1257) INFO - Generated Spotify authorization URL
(font_scanner.py:151) INFO - Scanning custom fonts directory (one-time)
(font_scanner.py:156) INFO - No custom fonts found
(__init__.py:116) INFO - Registered plugin source: Linux (MPRIS) (linux)
(__init__.py:116) INFO - Registered plugin source: Music Assistant (music_assistant)
(linux.py:99) WARNING - playerctl not installed. Install with: sudo apt install playerctl
(helpers.py:255) INFO - 
Application State Summary:
|- Time: 10:20 PM - Mar 01, 2026
|- Uptime: 0h 0m
|- Mode: Idle
|- Current Song: None
|- Active Source: None
|- Metadata Fetches:
|  |- Spotify: 0
|  |- Windows Media: 0
|  `- Spicetify: 1
(music_assistant.py:138) INFO - Connecting to Music Assistant: http://192.168.0.168:8095
(spotify_api.py:1281) INFO - Completing Spotify authentication...
(spotify_api.py:1320) ERROR - Spotify OAuth error during token exchange: error: invalid_client, error_description: Invalid client
(server.py:3447) ERROR - Failed to complete Spotify authentication: error: invalid_client, error_description: Invalid client
(spotify_api.py:1257) INFO - Generated Spotify authorization URL
(spotify_api.py:1281) INFO - Completing Spotify authentication...
(spotify_api.py:1320) ERROR - Spotify OAuth error during token exchange: error: invalid_client, error_description: Invalid client
(server.py:3447) ERROR - Failed to complete Spotify authentication: error: invalid_client, error_description: Invalid client
(sync_lyrics.py:709) INFO - Main loop heartbeat - iteration 600
(spotify_api.py:1257) INFO - Generated Spotify authorization URL
(spotify_api.py:1281) INFO - Completing Spotify authentication...
(spotify_api.py:1320) ERROR - Spotify OAuth error during token exchange: error: invalid_client, error_description: Invalid client
(server.py:3447) ERROR - Failed to complete Spotify authentication: error: invalid_client, error_description: Invalid client
(sync_lyrics.py:709) INFO - Main loop heartbeat - iteration 1200
(spotify_api.py:1257) INFO - Generated Spotify authorization URL
(sync_lyrics.py:709) INFO - Main loop heartbeat - iteration 1800

[AnshulJ999]

Hey @adam-kosik !

Thanks for sharing the logs! So the logs clearly show an 'Invalid Client' error. I can't say for sure exactly what's causing this, but something went wrong with your SyncLyrics config.

The nuclear option would be to delete the container, its volume/mount data, everything, and start fresh. You can backup first of course. It's safe to restore 'lyrics database' and 'album art database'. Also safe to restore 'settings.json' if you need to.

Otherwise, please try this:

1. Delete .cache and .spotify_cache and other cache files/folders you see from wherever your SyncLyrics data is stored. This contains your old/stale Spotify tokens.

2. Re-check your .env variables once more. I'd recommend trying to regenerate a new Client Secret, and copy-pasting them fresh to make sure there's no errors there.

3. Also please confirm from logs ur new Client ID is this:

Spotify Client ID: 7cf0c211...

Just to ensure there's no stale ENV variables interfering.

Then recreate the container.

If that doesn't work, I can only recommend the nuclear option I guess. And if that still doesn't work, I'm out of ideas for now 😅

[adam-kosik]

Thanks a lot @AnshulJ999 for all these suggestions. Will definitely do and keep you informed!