Cannot Discover Equipment Group

Running OH 3.3 using GUI configuration

I have previously created numerous Alexa items but this time for a new TV I tried creating as a Group endpoint.

If I add Alexa metadata at the Group level it doesn’t get discovered, but if I remove it the group members get discovered individually.

I’ve read about others having the same issue but none of those solutions seem to apply here.

Thanks for any help


Can you please share the Alexa metadata configuration for your group endpoint including the group and the relevant item members?

Here is the configuration of Kitchen Tv Group without any Alexa metadata

Here are the members of the group

Here are the details of the Mute item

The Alexa metadata details for that Item

If I run Discover devices the three members of the Group are created as separate Devices in Alexa

If I include Metadata on the Kitchen TV Group item then no devices are discovered.

My expectation is that with the correct Metadata on the Group item a single Kitchen TV device would be created in Alexa that would include all the attributes of the members, but this is not clearly described in the OH documentation. I have seen some members in the community were successful in creating Equipment endpoints.

Here is how I have been configuring the Group Metadata.

Any ideas on where I’m not configuring correctly?

The metadata configuration looks good from what I can see. Have you tried to remove your existing discovered devices in Alexa prior to triggering a discovery?

I removed all from Alexa and did another discovery with same result. All the original devices were created again.
Next step, capture logging during discovery?

Is your Input device discovered individually when it’s not attached to the group? Also, can you please share the Alexa metadata configuration for that item?

Yes, the individual Items are discovered when they’re not part of a Group.
Yesterday I created a completely new Equipment Group with another TV and it worked as expected.

In thinking about this, I suspect the issue is due to creating a Group name (Kitchen TV) when there is already another single linked Item that contains Kitchen (Kitchen Speakers). Alexa may not know how to reconcile this conflict.
I’m going to try again with a new Group name for this TV and my bet is it will work.

Thanks for your support in helping me work through this!

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Having multiple device with the same location name part of their device name (e.g. Kitchen Light, Kitchen TV, …) shouldn’t prevent the discovery. If you had duplicates, you would be getting a voice response asking you to clarify the specific device you are trying to control.

The device uniqueness is based on the item name. My follow-up suggestion would have been to change the item name of your group.

You’re right of course and I proved this to myself by trying various configurations.
I created a new Group and it worked, but to expedite testing the Group only had two switch Items, on-off and mute. When I added Volume and Input it failed to discover so I added them one at a time, and it turns out the Input Item was preventing discovery.
I suspect this is because, by default, the Input item is created with a massive default list of 117 values!

I’m going to edit this down to a short list of only what’s really needed and confirm the Item can be correctly discovered.
What is the maximum number of input values Alexa will support?

Just to wrap this up, once I reduced the number of Input values the Item was discovered correctly.

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Correct if you don’t provide the supportedInputs metadata parameter, the skill will default to the item state description options if available.

So after looking into this one closer, the issue is not that the Alexa API limits the number of input values but a limitation in the cookie property generated by the skill for each endpoint and included in the discovery response that is sent back to the Alexa API. That property is used to cache the endpoint configuration so that subsequent requests for a given endpoint don’t need to spend time figuring out that information again.

The limitation is 5000 bytes, which explains why your input device was discovered on its own but not when it was part of your group endpoint since with the latter, all Alexa-related item configs part of the group are included in the cookie property.

Anyway, this limitation wasn’t something that was considered up until now. Although, this is mostly an edge case, we are looking to introduce a hard cap, such a limit to 150 options while also compressing the property content, which would allow such endpoint to be discovered in the future.

That would have been my suggestion to work around the current limitation.