WhatsApp.webhooks.start()

This starts the web server listening the defined port for webhook events. It handles both GET and POST requests made to the webhook endpoint path.

GET request is verified using the webhook verification token, a successful match sends back the hub.challenge to the Cloud API request in order to validate a webhook subscription. A successful verification string match sends back the challenge code with a 200 response. A verification string match failure results in a 401 status code response and your callback is called with an error message, a 401 value for the status code, and the request headers.

POST request are received and the payload is checked against for authenticity against the x-hub-signature-256 using the shared app secret. A calculated x-hub-signature-256 string match failure results in a 401status code response being sent and your callback is called with an error message, a 401 value for the status code, the request headers, and the request body.

Example:

Start the web server and print out valid message webhook event bodies.

import WhatsApp from 'whatsapp';

const senderNumber = 12345678901234567890;
const wa = new WhatsApp( senderNumber );

async function webhookCallbackFunction( statusCode, reqHeaders, body, resp, err )
{
    console.log(
        `Incoming webhook response status code: ${ statusCode }\n\nHeaders:
        ${ JSON.stringify( reqHeaders ) }`
    );

    if( resp )
    {
        if( body?.entry[ 0 ].changes[ 0 ].field == "messages" && body.entry[ 0 ].changes[ 0 ].value.messages )
            console.log( `Messages Object: ${ JSON.stringify( body.entry[ 0 ].changes[ 0 ].value.messages ) }` );

        // Send a 200 so the webhooks service knows you received the message
        resp.writeHead( statusCode );
        resp.end();
    }

    if( err )
    {
        console.log( `ERROR: ${ err }` );
        resp.end();
    }
}

wa.webhooks.start( webhookCallbackFunction );

Arguments

1. webhookCallbackFunction : webhookCallbackFunction — The callback that gets called during POST requests made to the webhook listener endpoint.

Returns

boolean — the HTTP server running state.