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Webhook source (HTTP)

This source exposes an HTTP endpoint, meaning it acts as an HTTP server. It can be used as a target endpoint for 3rd-party webhooks from any SaaS app that supports webhooks, or can be used as a generic way to ingest events to TriggerMesh via HTTP. The Webhook source creates an event for each request received.

Compared to the CloudEventsSource, the Webhook source can accept arbitrary data (e.g. any JSON) and does not require the request to conform to the CloudEvents specification.

With tmctl:

tmctl create source webhook --eventType <my.event.type>

On Kubernetes:

kind: WebhookSource
  name: sample
  eventType: com.example.mysample.event
  eventSource: instance-abc123

    - path
    - queries

  basicAuthUsername: customuser
    value: abc123secret

      kind: RedisBroker
      name: triggermesh


  • Name: all TriggerMesh components need a unique name per namespace.
  • Broker: request converted into CloudEvents will be sent to this location.
  • EventType: string that identifies the purpose for all messages produced from this source.
  • EventSource: string that identifies the origin for all messages produced from this source.
  • Basic Auth Username: (optional) HTTP basic authentication username.
  • Basic Auth Password (optional) points to a secret that contains the HTTP basic authentication password.

Events produced have the following attributes:

  • type: defined by the user in the WebhookSource configuration, e.g.
  • source: defined by the user in the WebhookSource configuration, e.g. cool-tshirts
  • Schema of the data attribute: depends on what the client sends to the Webhook
  • datacontenttype is set to the Content-Type received at the incoming request

Cloud Event data example (same as received body):

  "operation": "signup",
  "user": {

See the Kubernetes object reference for more details.

Guide: use tmctl to create a Webhook source

Create an HTTP endpoint

HTTP is one of the easiest ways to send events to the Broker from whichever HTTP client you prefer (Postman, Curl, API Tester...). To do this, let's create a Webhook Source:

tmctl create source webhook --eventType contact.created

We're declaring that events of type contact.created will be sent to this endpoint. This event type will be part of the event metadata as it flows through TriggerMesh, and can be used later on for routing.

Obtain the URL

Find the Webhook Source URL:

tmctl describe

The output should look something like this:

tmctl % tmctl describe

Broker     Status
foo        online(http://localhost:59882)

Source                Kind              EventTypes          Status
foo-webhooksource     webhooksource     contact.created     online(http://localhost:59936)

As you can see, tmctl describe displays useful info about your current configuration. It lists all the sources, targets, and other components you've defined, and their properties.

Copy the webhooksource URL, in this case http://localhost:59936 (this will vary depending on your environment). Do not confuse this with the Broker's URL.

Send an event over HTTP

We'll use curl here. Remember to replace the endpoint URL with yours.

curl http://localhost:59936 -d '{"http":"is easy"}' -H 'Content-type: application/json'

The event should show up in tmctl watch:

2022/11/09 16:17:38 Watching...
☁️  cloudevents.Event
Context Attributes,
  specversion: 1.0
  type: contact.created
  id: 8bce0cd7-74a2-443b-b8ef-825473cc5c51
  time: 2022-11-09T15:37:00.435002345Z
  datacontenttype: application/json
    "http": "is easy"