Broadcast WhatsApp Message Templates with Flow Builder & Postman

In this guide, you will learn how to broadcast any WhatsApp Messages Template with Flow Builder by creating a flow using a webhook as a trigger and Postman to trigger the webhooks.

Before you begin

Before you get started, you will need to complete the following 3 steps first:

E.g. Hi {{1}},

This is an automated system that helps facilitate your registration process through WhatsApp. Visit this link to find out what documents you need before we get started:

Reply with Start when you're ready to proceed.

Step 1: Create a webhook trigger flow

1. Go to Flow Builder and create a new flow.

2. Select Webhook as the trigger.

3. Add phone and firstname as your webhook variables.

4. Done? Awesome! Add a Send WhatsApp HSM step below your Webhook. Choose your template, add phone as the Recipient, and firstname as variable 1.

5. Publish your flow in the top-right corner of your screen, and you're good to go!

Step 2: Create a CSV list

1. Create an excel or Google form. If you have an existing contact list, please update it like the following:

Make sure the phone number starts with the country code.

2. Save your file as contacts.csv when you are done. Don’t forget to save your file as a CSV format.

Step 3: Import contacts.csv into Postman

1. Open your flow, click on the Webhook step and tap copy. Paste the Flow Builder Webhook URL into the request URL in Postman. The HTTP Request Method can be GET or POST.

2. Copy phone and firstname from the Configure webhook variables section into Query Params as KEY values:

  • Type {{phone}} in the phone VALUE field

  • Type {{firstname}} in the firstname VALUE field.

3. Press Save. A SAVE REQUEST window will pop up, tap + Create Collection and name it WA Broadcast. Once the new collection is created, save your request by clicking on the Save to WA Broadcast button.

4. Choose Runner from the top row. A Collection Runner window will pop up, select your WA Broadcast collection — the saved request will populate into the RUN ORDER.

5. Click Select File and open contacts.csv.

6. Click the RUN WA Broadcast button. Runner will then send the webhook request to the webhook flow following from the 1st row until the last row of the contacts.csv file.


  • Passed: A green flag and 204 No Content.

  • Failed: A red flag and 400 Bad request. If that’s the case, please make sure you did not miss any previous steps.

And that’s it! 🎉Now you know how to broadcast any WhatsApp Message Templates through Flow Builder using Postman.

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