WebSocket

[mpw96]

I just upgraded to 2025.3.1, checked the "use Websocket" box and restarted the integration. I see immediate reaction on the other side if I e.g. change the charge limit either in the evcc UI or in home assistant. Long story short: Works for me. Thank you! Good work.

[UDicke]

@marq24 this new feature is amazing, works brilliant as well as the whole integration! Thanks for this and your integration at all! 👍 💯

[steps56]

I activated this now also.
But may the mantainer or somebody else with knowledge, explain to me at a kind of noobway, which benefits this webhook change may give to the integration, even better to me ?
Just want to understand and not follow blind without knowing.
Thanks für explanations in advance.

[marq24]

poll vs push

When using poll-strategy, HA will request (in the defined update interval) data from evcc-server... So in the time in between two poll's, evcc backend can already change it's state - and you will just receive the new data with the next polling-interval... So the natural approach to solve this "out-of-sync" situation is to select a small update interval - like 5 sec...

But using this short update-interval comes with 'costs': You increase the overall load on your hardware / network just to be 'as short as possible' out of sync...

This all can be solved when evcc will push new information to HA when ever it becomes available... so the systems are always (with few ms of latency) in sync... And only exchange data when it's necessary...

following push(& listing)-strategy should be environment friendly - instead of 'brute-force' polling...

[steps56]

THANKS a lot.

[thecem]

Hi @marq24 would this be helpfull for you: https://developers.home-assistant.io/docs/add-ons/communication/#home-assistant-core ?
evcc-io/hassio-addon#142

[marq24]

imho - nope - the article is about AddOn's - I have implemented an integration

[marq24]

and just as heads-up... Here is how all this is working now...

The Integration will start with the configured update-interval and start to "poll" the initial data from evcc - when websocket option enabled (in the config), then shortly after the start of the integration, HA connect to the websocket of evcc and start to receive/listen to new data...

As soon as new data arrives, the integration let HA know, that new values have arrived and that entity states/attributes should be updated. Typically evcc is publishing the data-updates in 'waves' - sending multiple websocket messages in a short period of time.

In order to deal with this waves the integration will hold back the update-notification for 0.3 seconds. If in this time frame another websocket message was received, the (outdated) update notification will be canceled and a new update-notification (that wait again for 0.3) will be generated. So in theory, when evcc will constantly publish new data in less then 0.3 seconds all update notifications will be canceled... But I don't expect that we will ever run in such a situation.

I have implemented this notification delay in order to reduce the system load in HA. Every time the code execute such an HA-update you will see in the debug log a default HA message: Manually updated evcc_intg data (even if the data was updated 'automatically')

Additionally the integration will start a watchdog - every 60 seconds this job is checking, if the websocket is still available (e.g. evcc might be restarted)... You see in the log's a message: Watchdog: websocket is connected ...

If the websocket is not available any longer, the websocket connection will be reestablished... This check will also/additionally check, if some static data (like tariffs) needs to be updated ( - check for optional required 'tariffs' updates). If 'yes' [in case of tariffs every 1h], the integration will update this information by requesting data from evcc (via regular API calls). [JFYI, tariffs-data is not not available via data provided by the websocket - yes there is a 'forecast' object in the websocket - but this is slightly different then the data returned by the tariffs API endpoint]

[steps56]

Thanks a lot about explanation 👌.