Hi @DanFM 

You may have to try this approach…

Create a Journey in Campaign Monitor to set a value for a custom field when a Subscriber enters a Segment.

Then use Campaign Monitor Webooks to trigger a Zap: https://www.campaignmonitor.com/api/v3-3/webhooks/

Zap trigger: Webhook - Catch Hook

https://zapier.com/apps/webhook/help

This will generate the unique webhook URL to configure in Campaign Monitor.

Zap Step 2: Filter

Make sure to add a Filter to check for the existence of the custom field value you expect.

Use the Campaign Monitor API to create a webhook subscription for Subscriber Update

https://www.campaignmonitor.com/api/v3-3/lists/#creating-a-webhook

Hey @DanFM 

Were you able to get the desired workflow up and running following Troy’s suggestions here? 

Either way, I’d recommend reaching out to our Support team to submit a new feature request for a “new subscriber in segment” type of trigger to be added. You can do that here: https://zapier.com/app/get-help 

Super keen to ensure you’re all set here so please let us know if you’re in need of any further assistance here in the meantime!