Alexa smart home skill and letsencrypt certificates

With the recent Insteon shutdown, I’ve made the transition over to Home Assistant. Locally I’ve got it all setup and working great, and now I’m ready to setup Alexa integration.

I like to consider myself as a tech savvy individual, so I’ve gone down the path for setting up my own skill per the documentation. The lambda can communicate with my Home Assistant, but when I try to setup the skill and link it to my account, it gives me the most unhelpful “We were unable to link Home Assistant at this time” message.

Reading the documentation, it appears for account linking a smart home skill you cannot use a letsencrypt certificate.

Does anyone have any suggestions for a free SSL provider that works with duckdns and is supported for smart home skills?


Did you consider using the Home Assistant Cloud solution? It comes with pre-packaged Alexa integration. It does cost money ($6.50 per month) but it is very easy to setup and it is updated with HA so you don’t need to worry about managing the solution. Plus it helps pay for dedicated staff to develop HA.

So the certificate for is issued by Let’s Encrypt
Screen Shot 2022-04-19 at 2.10.05 PM

I see what you mean in the docs but it’s really a head-scratcher. Because if Let’s Encrypt certificates actually didn’t work almost no HA users would be able to connect to Alexa. All cloud users would fail and most non-cloud users would too.

One thing that does trip people up though is this requirement:

The Alexa Smart Home API requires your Home Assistant instance to be accessible from the internet via HTTPS on port 443

Did you expose HA on port 443 or did you keep it on 8123 (or some other non-standard SSL port of your choice)? Because Alexa requires the standard port 443.

I have Alexa smart home skills set up, and i’m using HA’s DuckDNS with Letscrypt add-on, so I think that documentation means something else. I don’t know why it doesn’t work for you though. I do have the nginx SSL proxy add-on running, I think that may have something to do with it.