If you're looking for webhook support plus full transcript access (not just summarized notes), I'd recommend checking out ChatterBox as an alternative to Recall, but no sales call to start using, self-service, and less expensive (consumption model .09/hr). It supports real-time transcription and meeting data across platforms—including Zoom, Meet, and Teams. I don't believe they have a Discord or Slack integration, but it's built with developers in mind - I'd bet they'd explore it.

https://chatter-box.io/