Up to 2 attachments (including images) can be used with a maximum of 524.3 kB each and 1.0 MB total.
Yup. Valve isn't supported per se, but we do support 'on' and 'off' commands which you could apply to the valve.
Yo can configure your device on aws iot and then write control logic in smart home skill adaptor lambda code.
No one has followed this question yet.
Will changes in Lambda configuration cause necessity for re-certification to go live?
Control group take to long to get request, leads to "I am not quite sure what went wrong" message
Can I customise the response of Smart Home?
"I am not quite sure what went wrong" message from Alexa, but executes the Lambda for the skill and device responds
What is the logic behind restrictions on what devices can be added to a scene