[tado] Intermittent HTTP 400 error when refreshing access token

[andrewfg]

Tado announced a new OAuth workflow from March 15th 2025, and in fact their servers already supported it a couple of weeks earlier. In #18354 and #18433 I implemented that workflow and tested it (prior to the March 15th deadline). In reality they started hard enforcement about one week later (different timing for different users).

It seems that my implementation is not (yet) 100% stable. When I tested it prior to March 15th there were no errors. However now (March 26th) their server throws intermittent HTTP 400 errors when the access token is being renewed. The problem is that my initial testing was with just one Thing, but now I am running it with eight Things, and there is a concurrency issue if multiple Things try to refresh the access token in parallel.

The binding does nevertheless continue to retrieve data (the things stay online) -- albeit that there are gaps in the data.

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Sample log output is below..

2025-03-26 15:34:45.271 [DEBUG] [oauth2client.internal.OAuthConnector] - grant type refresh_token to URL https://login.tado.com/oauth2/token success

2025-03-26 15:44:46.915 [ERROR] [oauth2client.internal.OAuthConnector] - grant type refresh_token to URL https://login.tado.com/oauth2/token failed with error code invalid_grant, description The refresh_token is invalid.

2025-03-26 15:44:46.923 [DEBUG] [oauth2client.internal.OAuthConnector] - grant type refresh_token to URL https://login.tado.com/oauth2/token success

Will be fixed by #18450

[kaikreuzer]

@andrewfg Is it correct that this is fixed and the issue can be closed?

[andrewfg]

Closing as resolved in OH Core

[fwPunsher]

Hi there, i have noticed some strange behavior since upgrading to 4.3.4. Im posting here since it might be related to this issue. My problem is, that after some hours I stop receiving any updates for all tado things. When this happens Its also no longer possible to disable the bridge thing. I cant find anything in the logs.
Last message I get is:

[ado.internal.handler.TadoZoneHandler] - Updating state of home XX and zone 1

Afterwards there are no more entries related to the binding.
Whats really weird is, that this appears to be also affecting the openweathermap binding.

[andrewfg]

noticed some strange behavior since upgrading to 4.3.4

There are a couple of updates in the pipeline. They will probably hit v5.x snapshot soon and 4.3.5 in a couple of weeks.