Invalid JSON from Input Block to Virtual Button to Workflow

I am sending this input block’s data from a User Experience Dashboard via a virtual button to a workflow:

Full device info is shared in the dashboard in context:

However when I try to submit the data it shows that the data does not end up as valid JSON:

It seems {{}} and {{}} are valid JSON as they evaluate correctly everywhere else on the dashboard.

See that {{}} evaluates to 42003


In User Experience:

Hi Leo,

You are seeing this error as {{ctx.deviceId.tags}} is an object, and the intended use for .tags is to return just one tag, or a stringified object. The documentation states:

{{ctx.VARIABLE_NAME.tags}} is a reference to the tags associated with the device; you may wish to iterate over all tags or get the value of a specific tag with a string template such as {{ctx.VARIABLE_NAME.tags.TAG_KEY.[INDEX]}} , where INDEX is usually 0 since tag values are returned as an array.

If you would like to get the tags as an object, I would recommend doing so in the workflow. You can do this by using the deviceId you are sending in a Device: Get Node and checking the box to get return tags as an object.


Data comes in as the device name:

Then use the get device node to find the id and tags:

Works great, thanks!

I did however find one thing perplexing:

It works if I send the device name as such:

But also shows a JSON error if i send the device id as such:

Hi Leo,

The id has to be formatted as a string to pass the JSON validator:

{ "sensor" : "{{}}" }


I need to pay more attention to variable types apparently. :sweat_smile:
Thanks again, Julia.