Webhook trigger "webhook from an external page" implementation in our app?

Develop, Build & Integrate APIs & Integrations
1

Hi,

when I try to create a webhook event for a workflow (trigger → Custom events & external events → Received a webhook from an external app → Add a webhook), the process forces me to test the webhook.

I tried to call the created URL with standard authentification as for APIs with GET which does not work. For POST or PUT there may be some properties required, but I can’t find any documentation how to implement external webhook events into my app.

Regards

Harald

2

If there are an alternate option to trigger the worklow by API, it would be welcome.

3

To test the webhook, Postman is the fairly standard app that most people use.

If you don’t want to download an app or use their web version, you can also use curl or wget which allows you to set the method type. Postman is the easiest though.

Not sure what you mean by “implement external webhook in your app” but 2026.3 has access to axios which can also make the request.

4

Hey @hkampen,
Thanks for posting in the Community!
@MichaelMa - thank you for the context!
I’d also like to tag in a few other experts to see what other insight we might be able to gather. @louischausse, @CateDuarte, and @ChristinaKay - do any of you have anything else you might be able to add?
Shane, Senior Community Moderator

5

For this kind of workflow trigger, I’d first separate two things:

  1. authenticating against HubSpot APIs
  2. sending a webhook payload to the workflow trigger URL

The workflow webhook URL is not usually called the same way as a normal HubSpot API endpoint. You generally need to send a POST request to the generated URL with a JSON payload that matches what the workflow expects, rather than trying to call it with standard HubSpot API auth and GET.

I’d test with something simple first:

  • create the webhook trigger
  • send a POST request from Postman or curl
  • include Content-Type: application/json
  • send one or two simple properties in the body
  • confirm HubSpot receives the test
  • then expand the payload to your real app structure

The important design question is what object the workflow should act on after receiving the webhook. You’ll want a stable identifier in the payload, such as email, record ID, external ID, deal reference, or company domain, so the workflow/custom code can safely find the right HubSpot record.

Otherwise the webhook may fire correctly, but the downstream CRM update can still be unreliable.

6

Sending a request ist not a problem. I can do that very quick with Python and don’t need Postman or simular apps.

I think I can figure it out how the payload must look like to trigger the workflow for one company. I have to write the AI Breeze summery into a company field to use it in a internal app. If I do that daily, all of our AI credits are used after a few days :blush:

7

Hi Harald! Wanted to chime in that the webhook triggers are actually a kind of custom event, you can also use the Custom events api to trigger workflows via API in the future. you can read more about custom events here!