> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.meetgail.com/platform/workflows/guides-and-recipes/recipes/trigger-from-a-webhook/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.meetgail.com/_mcp/server.

# Trigger from a Webhook

> Configure the Start node as a webhook so another system can start your workflow, then test it.

When you want another system, such as a website form or your CRM, to start a
workflow the moment something happens, you use a webhook. It gives your workflow
a private URL that the other system calls, and the details it sends come into the
run so later steps can use them.

## Nodes involved

* The Start node, configured as a webhook trigger.

## How to build it

### Configure the Start node as a webhook

On the Start node, set it up as a webhook trigger and define the fields you
expect the caller to send. See
[Triggers & Webhooks](/platform/workflows/core-concepts/triggers-webhooks) for the
full detail.

### Get the URL

Publish the workflow to get its webhook URL. Only published workflows have a
working URL. The URL is the credential: anyone who has it can start this one
workflow, so give it only to the system that needs it and keep it out of
anywhere public.

### Require a shared secret (optional)

If you want a value you can change later without recreating the workflow, add
a shared secret to the Start node's webhook settings and have the caller send
it with every request. Put it in a request header if the calling system lets
you set one. Editing the secret and publishing cuts off anyone still sending
the old value, on the very next request. See
[Triggers & Webhooks](/platform/workflows/core-concepts/triggers-webhooks) for
what a shared secret does and does not protect you from.

### Reference the incoming data downstream

The information the caller sends is available to later steps through the Start
node. Point a field at an incoming value like this:

```
start.body.email
```

Use whichever field names the caller actually sends.

### Test it

Send a sample request to the URL and watch the run in
[Testing & Debugging](/platform/workflows/core-concepts/testing-debugging) to confirm
the incoming data arrived where you expect. While you are still building, you
can also start runs by hand from there.

> **Note**
>
> Treat the webhook URL like a password. Anyone holding it can start this
> workflow, and adding a shared secret does not change that, because you have to
> give the caller the secret too. When a caller needs to genuinely prove who it
> is, start the workflow the way that requires real credentials instead. See
> [Triggers & Webhooks](/platform/workflows/core-concepts/triggers-webhooks).

## Related

#### [Triggers & Webhooks](/platform/workflows/core-concepts/triggers-webhooks)

The full picture of how webhooks start a workflow.

#### [Testing & Debugging](/platform/workflows/core-concepts/testing-debugging)

Send a test request and follow the run.

> Documentation for Gail, the AI platform for financial services. Learn how to set up GailGPT and Gail Agent to automate customer communications for insurance, banking, and finance.