GoHighLevel Workflows can send data straight to a LettrLabs webhook URL, without Zapier — a good option if you'd rather not depend on a Zapier connection at all.
Before you start
A LettrLabs Open API key and an inbound webhook connection (see Setup Guide: Open API & Webhooks).
A GoHighLevel Workflow with edit access.
Step 1: Create your LettrLabs webhook connection
In LettrLabs, go to Automations > Open API to generate an Open API key.
Go to Active Webhooks > Data Streams (Inbound) > Create, name the connection (e.g., "GoHighLevel"), and copy the Webhook URL.
Turn on OpenAPI Key authentication.
Step 2: Build the GoHighLevel workflow
In GoHighLevel, go to Automation > Workflows and set your trigger — a pipeline stage change, tag added, or form submission.
Add a Webhook action to the workflow.
Set the method to POST and paste in your LettrLabs Webhook URL.
Add a custom header
X-API-KEYwith your Open API key.
Step 3: Test and confirm receipt
Trigger the workflow once (enroll a test contact) and check the History tab on your LettrLabs webhook connection to confirm the payload arrived.
Step 4: Wire the connection to a mailing and map fields
Open the Automation (Integration Order) or Radius Mail setup, select the GoHighLevel connection under Select Webhook Connection, choose Mail to Recipients or Radius Mail, and map the fields from your test payload.
Step 5: Go live
Save the webhook connection with a name (exits Test Mode) and confirm the GoHighLevel workflow is turned on.
Want help wiring your first GoHighLevel workflow to LettrLabs? Reach out to our team.