Join image and javascript tracking in one visit

I would like to be able to join an image tracked visit together with a javascript tracked visit in to a single visit. Scenario:

We are using Piwik to track both emails and our main site. Our emails contain a link to visit our site. In the email, we use image tracking to track opens on the email. On our main site, we use javascript. If the user clicks the link in the email to visit our site, they start a new visit.

So there is a visit with one action for the email open, then another visit with all subsequent actions in the main site. I would like to be able to join the two in to one visit.

If this is possible now, could someone please inform me on how to do it? Otherwise, could this be added to the request of features.

I was thinking it could just be a common key that is passed to Piwik from both visits to join them in to one. I would also be willing to (attempt to) implement it if I know it would make it to the core.

I’ve created a ticket for this request. piwik.js: bridge third-party to first-party cookies · Issue #2394 · matomo-org/matomo · GitHub