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Wait For Webhook

Webhook is an HTTP-based callback function that facilitates the communication between the Conductor and other third-party systems. It can be used to receive data from other applications to the Conductor. Conductor currently supports Webhook integration with the following third-party systems only:

  • GitHub
  • Slack
  • Twilio
  • Stripe
  • Pagerduty
  • Zendesk
  • Twitter
  • Facebook
  • Sendgrid

You can leverage the Custom option for integrating other than the above-mentioned third-party systems.


"name": "webhook_task",
"taskReferenceName": "webhook_task_ref",
"inputParameters": {
"matches": {
"$['event']['text']": "$.{workflow.input.somevalue}"

Input Parameters

Writing Custom Matches

In the above example, you can see that the matches are described as follows:

"$['event']['type']": "message"

This means that the incoming event payload has a JSON path event.type, and it must be a message in order to match the webhook event with this task. You can define any custom JSON path based on the incoming event payload and write matches accordingly. You can also add multiple matches within the matches. All the matches will be calculated as AND operations within the matches.

    "matches" : {
"$['event']['type']": "message",
"$['event']['text']": "hello",

For example, the above one will match the webhook event payload where the event.type is message AND event.text is hello.

"name": "webhook_task",
"taskReferenceName": "webhook_task_ref",
"inputParameters": {
"matches": {
"$['event']['text']": "$.{workflow.input.somevalue}"

Creating Webhook

Let’s create a Webhook now.

  1. Navigate to Webhooks from the Conductor server.
  2. Click New Webhook.
  3. You need to fill in the following details:
Webhook NameProvide a unique name for your Webhook.
Workflow To Receive Webhook EventProvide the workflow name that is supposed to receive this webhook event.
Source PlatformChoose the platform from which this webhook event is going to be invoked. The currently supported platforms are GitHub, Slack, Twilio, Stripe, Pagerduty, Zendesk, Twitter, Facebook, Sendgrid & Custom.
Note: You can use the option custom for unsupported systems.
Start workflow when webhook events comeCheck this option to start a new workflow based on the data received from the webhook event. Once enabled, you need to choose the workflow to be executed.
  1. Click the Create button, and the Conductor will generate a Webhook URL, which will be unverified.

If you have enabled the option to Start workflow when webhook event comes, the event payload will be passed as input to the specified workflow.

The generated URL is to be copied to the platform from which the Webhook will be invoked. The URL status will be Unverified now.

Webhook with an unverified URL

Once the URL is verified based on the verification method, this is what a Webhook with a verified URL looks like.

Webhook with a verified URL

Supported Webhook Verification Methods by Conductor

Conductor supports the incoming Webhooks over HTTPS with the following verification methods:

  1. Header Verification - Validates a predefined header and value.
  2. Signature Verification - Validates the payload signature. This validation requires configuring the secret and header key on the Conductor side. And when the request comes, the Conductor will calculate the request payload hash and match it with the pre-configured header value.
  3. Challenge Verification - Used when the third-party system sends a challenge request that the Conductor server responds to establish trust.

Different Types of Webhook

1. Header-based Verifier Webhook

For this type of Webhook, each request must contain all the headers with the keys and values specified. The request will be ignored if the keys and values are not specified.

Header-based verifier webhook

So here, the URL is marked as verified when the first Webhook event comes with all the header keys and values configured.

Sample webhook receiving incoming webhook using cURL

2. Challenge-based Verifier Webhook

  • For this type of Webhook, the initial invocation must have a challenge parameter, and the same will be returned. This way, the Conductor marks the URL as verified. The Conductor would automatically accept the subsequent requests.
  • The URL is marked as verified when the challenge request comes from the system. If the URL is not verified, then all the requests will be ignored until the URL verification is completed via the challenge mechanism. The systems that support the challenge-based verifiers are Slack and Facebook.

Challenge-based verifier webhook

3. Signature-based Verifier Webhook

This type of Webhook is configured using the token from the source platform. This token is used to verify the signature of the request. The systems that support the signature-based verifiers are GitHub, Twilio, Stripe, Pagerduty, Zendesk & Twitter.

SystemHeader for request verification
  • Header X-Hub-Signature 256 will be used to request verification. It is the request body’s HMAC hex digest and is spawned using the SHA-256 hash function and the secret as the HMAC key.
  • secret - Provide the GitHub account’s secret key.
  • Header X-Twilio-Signature will be used to request verification.
  • AuthToken - Provide your AuthToken from the Twilio console.
  • Header Stripe-Signature will be used to request verification.
  • endpointSecret - Provide your endpoint’s secret for Webhook from Stripe.
  • Header x-pagerduty-signature will be used to request verification.
  • secret - Provide your Pagerduty’s secret token.
  • Header X-Zendesk-Webhook-Signature will be used to request verification.
  • SIGNING_SECRET - Provide your Zendesk’s signing secret for Webhook.
  • Header x-twitter-webhooks-signature will be used to request verification.
  • TWITTER_CONSUMER_SECRET - Provide your Twitter app’s consumer secret.

Signature-based verifier webhook

Here the URL is marked as verified when the request comes with the header configured and when the request payload hash in the header and the calculated hash on the Conductor side match.


Example using Postman

Consider the following workflow that waits for a webhook event from Postman:

Workflow with webhook task

Here the input matches are defined as:

"inputParameters": {
"matches": {
"$['data']['recipientId']": "${workflow.input.recipientId}"

The complete workflow JSON looks like this:

"name": "sample-webhook",
"version": 1,
"tasks": [
"name": "http_task_uzpd9",
"taskReferenceName": "http_task_uzpd9_ref",
"inputParameters": {
"http_request": {
"uri": "",
"method": "GET",
"connectionTimeOut": 3000,
"readTimeOut": "3000",
"accept": "application/json",
"contentType": "application/json"
"type": "HTTP",
"optional": false
"name": "webhook_task_myey4",
"taskReferenceName": "webhook_task_myey4_ref",
"inputParameters": {
"matches": {
"$['data']['recipientId']": "${workflow.input.recipientId}"
"optional": false
"inputParameters": [
"schemaVersion": 2,
"ownerEmail": ""

Next, create a webhook to invoke this workflow:

Webhook example

Under the field “Workflows to Receive Webhook Event”, choose the workflow that includes your webhook task created earlier. Since the platform is Postman, let’s choose the Source Platform as Custom.

Provider a header key and value. Let’s also configure to start the workflow “start-http-task” when the webhook event comes from Postman.

On saving the webhook, an unverified URL will be generated, as shown below:

Webhook with unverified URL

Since this is a header-based verifier, the URL will be verified once the first Webhook event comes with all the header keys and values configured.

Once the above workflow is run, and when the execution reaches the “WAIT_FOR_WEBHOOK” task, it waits for the event to come from Postman.

Workflow execution waiting for webhook event

Now, open Postman, create a new request with your webhook URL and change the method to POST.

Provide the header key and value, and the input matches in JSON format. Click Send, and it should return a 200 OK.

Sending POST request from Postman

Now, if we return to the webhook, you can see that the event has been received. This triggered the workflow in which the webhook task was added.

Workflow with webhook task triggered on receiving webhook event

You can see that the webhook URL has been verified now. And if you check the previous workflow execution, you can verify that it has been completed successfully.

Sample webhook workflow completed

We have also configured to start the workflow “start_http_task” on receiving this webhook event. You can verify the same from the Workflow > Executions page.

Workflow triggered when request came from Postman

Sending messages in a Slack channel

Integrating Conductor with other systems using Webhook can be leveraged for cases like creating chatbots, employee onboarding processes, automated scrum updates, automated issue creation on support channel messages, etc. Now, let’s visualize a sample case where you need to send a message in a Slack channel.

  1. Create workflows to send a message in a Slack channel.
  2. Create a Slack app that has permission to post to the Slack channel. Then, navigate to Features > Incoming Webhooks, and turn on Activate Incoming Webhooks.

Activating incoming webhooks for Slack app to enable permission to post in channels

  1. Create a webhook that listens for events from Slack. Check the above-mentioned example for creating Webhook.
  2. Once the unverified URL is generated, you can use this URL in the Slack app. Under Features > Event Subscriptions, turn on the toggle button Enable Events. Provide the unverified URL of the Webhook under the field Request URL.

Enabling events for connecting webhook with Slack app

  1. The URL would now be verified in both the Slack app and the Conductor side.
  2. Save the Webhook.
  3. Run the workflow. The current status of the workflow will be RUNNING.
  4. Open the Slack app and send the text message to the channel.
  5. The Workflow is completed now.