Before Starting with Flows

Configure the Public Key

Before creating a flow, you need to submit a public key to Meta. This key is used to encrypt user data, such as messages, steps, and media. To submit the public key, follow these steps:

Steps:

  1. Generate a new RSA 2048 3DES key using whatsapp.crypto.generate_rsa_private_key(). Save the private key in a secure location, as it will be required to decrypt data.

  2. Extract the public key from the private key using whatsapp.crypto.extract_public_key_from_private().

  3. Upload the public key to Meta using whatsapp.file_handler.send_whatsapp_business_encryption(), specifying the bot’s number ID.

Configure the Flow Endpoint

Flows do not use the same endpoint as the Meta API. Each flow can have a different endpoint, but once the URL is set, it is FIXED FOREVER. Configure a new endpoint in your message handler or use a separate server to handle the flow.

Flow Endpoint Health Verification

When setting a new endpoint, Meta will send a POST request to the endpoint with the following content:

{
    "encrypted_flow_data": "hXGXjcC...oRfyZY52eBHN2HAxbQ==",
    "encrypted_aes_key": "ojM2Vu+Hg...SqoGUHKYbfEa3AZwNA==",
    "initial_vector": "u2R1PtoAn+wC1do9A5fyDA=="
}

This content is encrypted with the public key you previously uploaded. To process it, you must decrypt it using the private key you saved, via whatsapp.crypto.decrypt_request(). The decrypted content will be a JSON with the following structure:

{
    "version": "3.0",
    "action": "ping"
}

You must respond with the following JSON:

{
    "data": {
        "status": "active"
    }
}

Before sending the response, you must encrypt it with the public key you uploaded earlier, using whatsapp.crypto.encrypt_response().

Now you are ready to create a flow!