[Integration Help] v10.11 Session commands via API return 204 No Content, do nothing

[shamoon]

(X-posting from https://github.com/orgs/jellyfin/discussions/15857 )

Hi all, I’m one of the Homepage devs. We're working on adding support for ≥ v10.11 API changes to our widget but running into some issues. GET calls work fine, but playstate/system commands (POST) are no-ops:

• Endpoints tried: POST /Sessions/{sessionId}/Playing/{command} (Pause/Unpause) and POST /Sessions/{sessionId}/System/{command}.
  
• Auth: Authorization: MediaBrowser Token="***", Client="Homepage", Device="Homepage", DeviceId="<stable-id>", Version="1.0.0". Initially tried with API key but when that didnt work I tried setting up getting a user token with 
  AuthenticateByName. Also tried ncluding controllingUserId when using a user token.
  
• Response: always 204 No Content, and the client doesn’t pause/unpause.
  
• Also I noticed /Sessions for the target session shows SupportsMediaControl: false and SupportedCommands: []
  
• Version: unstable 10.12.0 (Docker). No plugins.
  

Questions:

• Are these endpoints expected to work? If so, what enables SupportsMediaControl/SupportedCommands so playstate commands take effect?
  
• If not, which clients/endpoints are currently supported for remote control?
  
• Is there a recommended flow/setting to allow remote control from external integrations?
  

Thanks for any pointers 🙏