How to send a post to WhatsApp Channel via API

WAHA, Free Self-Hosted WhatsApp API, supports WhatsApp Channels , a brand-new feature introduced by WhatsApp. It is a one-way broadcast tool that allows administrators to send various content types such as text, photos, videos, and polls. Users receive push notifications from the channel, similar to a private message.

In this article, we give you a Step-By-Step guide how to send messages to WhatsApp Channels using WAHA - free, self-hosted WhatsApp API!

We’ll install it on your own laptop or server, so no suspicious services have access to your WhatsApp account.

Step 0. Requirements #

WAHA works on top of Docker, that’s the only think you’ll need!

👉 Please follow the Docker official guides to install it on Linux, Windows, and macOS

Step 1. Run WAHA #

After you installed Docker - you’re ready to run WAHA!

docker run -it --rm -p 3000:3000/tcp --name waha devlikeapro/waha

# It prints logs and the last line must be
# WhatsApp API is running on: http://[::1]:3000

It may take time to download the image, depending on your internet speed.

If you’re using ARM processor (like Apple M1/M2) run the following commands instead:

# Download the image
docker pull devlikeapro/waha:arm
# Rename it, so you can use devlikeapro/waha image in other place
docker tag devlikeapro/waha:arm devlikeapro/waha
# Run the same command!
docker run -it --rm -p 3000:3000/tcp --name waha devlikeapro/waha

# It prints logs and the last line must be
# WhatsApp API is running on: http://[::1]:3000

👉 Now, open Dashboard at http://localhost:3000/dashboard

You’ll see WAHA Dashboard:

Step 2. Run session #

Now you start default session (current status should be STOPPED).

You can leave all configuration parameters by default:

Step 3. Scan QR #

Wait until the session status is SCAN_QR and click on “camera” icon:
👉 If instead of QR you see Click to reload QR - stop the session and start it again.

You’ll see QR code from WhatsApp Web app, now get your phone with installed WhatsApp application and scan the QR:

The session status will move to WORKING status:

Step 4. Get Channel ID #

One step before you can send a message to you Channel - you need to get Channel ID in format 123123123@newsletter to know where to send a message.

You can just execute the following curl command:

curl -X 'GET' \
  'http://localhost:3000/api/default/channels?role=OWNER' \
  -H 'accept: application/json'

In the response you’ll see all channels, choose one and copy id:

[
  {
    "id": "111111111111111111@newsletter", // <========= copy that
    "name": "Channel Name",
    "role": "OWNER",
    ...
  }
]

As alternative to curl, you can use WAHA Swagger for that, open it at http://localhost:3000/#/channels , scroll down to Channels section.

• Find GET /api/{session}/channels endpoint and expand it
• Click Try it out
• Choose role=OWNER if you have your own channels or role=ADMIN if you’re admin in the channel (you can not send messages if you’re SUBSCRIBER in the channel)
• Click Execute

Step 5. Send a message to WhatsApp Channel #

Now we’re ready to send first messages to WhatsApp Channel via API!

Replace 123123@newsletter with your newsletter id, like 29847512@newsletter in the bellow command:

curl -X 'POST' \
  'http://localhost:3000/api/sendText' \
  -H 'accept: application/json' \
  -H 'Content-Type: application/json' \
  -d '{
  "chatId": "123123123123@newsletter",
  "text": "Hi there!",
  "session": "default"
}'

As alternative to curl, you can use WAHA Swagger for that, open it at http://localhost:3000/#/chatting , scroll down to chatting section.

• Find POST /api/sendText endpoint and expand it
• Click Try it out
• Replace 123123@newsletter with your newsletter id, like 29847512@newsletter in the bellow command
• Click Execute

What is next? #

🎉 You’ve sent the first message to WhatsApp Channel using WhatsApp API! 🎉

Here’s what you can lear next:

• Check the full 📢 Channels documentation
• Learn more about how to send images 📤 Send messages to WhatsApp Channel via API
• Learn how to 📥 Receive messages from WhatsApp Channels via 🔄 Webhooks