Hi Simon,
Ideally, I’d like the corresponding ticket in Zendesk to be marked as Solved, with a tag indicating the forum post that was the solution.
Ah ha, that’s very useful! If worse comes to worst I can set up a Vercel app to poll Discourse for posts with that tag, then update Zendesk. It wouldn’t be ideal since it would have to run as a cron essentially but it would be better than having to do it manually.
Yes, the Zendesk API is quite rich, and can handle a number of different requests. The webhook would have to be able to send a PUT since that’s what Zendesk would be expecting for updating a ticket, but other than that it should be trivial. See their API docs for more details.
It looks like the Discourse API only does POSTs on its webhooks. I’ll have to play around with this, maybe I’ll still need that Vercel setup but instead have it accept a POST which then triggers a PUT to Zendesk. Hopefully there’s a cleaner solution than that.