API Documentation

Integrate WhatsApp messaging into your application with our simple REST API. Send text, images, audio, video, and documents programmatically.

bolt

Quick Setup

Get started in under 5 minutes with your API token and a single endpoint.

shield

Secure by Default

Bearer token authentication over HTTPS with enterprise-grade security.

webhook

Real-time Webhooks

Receive incoming messages and status updates instantly via webhook callbacks.

Base URL

https://megamsg.app/api

Authentication

All API requests require two credentials: your Instance ID and a Bearer Token. Both are provided when you create a WhatsApp instance in the dashboard.

warning

Keep your credentials secret

Never expose your Instance ID or API token in client-side code or public repositories.

Required Headers

Include both headers in every API request:

HTTP Headers

Authorization:  Bearer your_api_token_here
X-Instance-Id:  your_instance_id_here

How It Works

1

Create an Instance

From your dashboard, create a new WhatsApp instance and scan the QR code.

2

Copy Your Credentials

Each instance gets a unique Instance ID and a 64-character Token. Copy both from the dashboard.

3

Start Sending

Use the token in your API calls to send messages through the connected WhatsApp number.

POST

Send Message

Send a text, image, audio, video, or document message to a WhatsApp number.

Endpoint

POST /api/whatsapp/messages/send

Request Parameters

Parameter	Type	Status	Description
phone_number	string	Required	Recipient phone with country code (e.g. `+201234567890`)
type	string	Optional	Message type: `text`, `image`, `audio`, `video`, `document`. Default: `text`
text	string	Required*	Message content. Required when type is `text`.
media	string	Required*	URL or base64 of media. Required for `image`, `audio`, `video`, `document`.
caption	string	Optional	Caption for media messages.
mime_type	string	Required*	MIME type. Required for `document` type.
file_name	string	Required*	File display name. Required for `document` type.
ptt	boolean	Optional	Push-to-talk (voice note). Only for `audio` type.

Code Examples

cURL

curl -X POST https://megamsg.app/api/whatsapp/messages/send \
  -H "Authorization: Bearer YOUR_TOKEN" \
  -H "X-Instance-Id: YOUR_INSTANCE_ID" \
  -H "Content-Type: application/json" \
  -d '{
    "phone_number": "+201234567890",
    "type": "text",
    "text": "Hello from MegaMsg! 🚀"
  }'

PHP (Laravel)

$response = Http::withToken('YOUR_TOKEN')
    ->withHeaders(['X-Instance-Id' => 'YOUR_INSTANCE_ID'])
    ->post('https://megamsg.app/api/whatsapp/messages/send', [
        'phone_number' => '+201234567890',
        'type'         => 'text',
        'text'         => 'Hello from MegaMsg! 🚀',
    ]);

$data = $response->json();
// { "ok": true, "to": "+201234567890", "type": "text" }

Node.js (fetch)

const res = await fetch('https://megamsg.app/api/whatsapp/messages/send', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer YOUR_TOKEN',
    'X-Instance-Id': 'YOUR_INSTANCE_ID',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    phone_number: '+201234567890',
    type: 'text',
    text: 'Hello from MegaMsg! 🚀',
  }),
});
const data = await res.json();

Python (requests)

import requests

resp = requests.post(
    'https://megamsg.app/api/whatsapp/messages/send',
    headers={
        'Authorization': 'Bearer YOUR_TOKEN',
        'X-Instance-Id': 'YOUR_INSTANCE_ID',
    },
    json={
        'phone_number': '+201234567890',
        'type': 'text',
        'text': 'Hello from MegaMsg! 🚀',
    }
)
data = resp.json()

Response

✓ Success (200)

{
  "ok": true,
  "to": "+201234567890",
  "type": "text"
}

✗ Error (401)

{
  "ok": false,
  "message": "Unauthorized."
}

Webhook Events

Configure a webhook URL in your instance settings to receive real-time events. We will POST JSON payloads to your URL with retry logic (3 attempts).

Message Received

Your webhook URL will receive incoming messages in this format:

POST → your-webhook-url

{
  "type": "message",
  "message": {
    "id": "ABCDEF123456",
    "from": "201234567890",
    "push_name": "John Doe",
    "text": "Hello!",
    "timestamp": 1714650000,
    "is_group": false,
    "type": "text"
  },
  "timestamp": "2026-05-02T12:00:00+00:00"
}

Webhook Fields

Field	Type	Description
type	string	Always `"message"` for incoming messages
message.id	string	Unique WhatsApp message ID
message.from	string	Sender phone number (without @s.whatsapp.net)
message.push_name	string	Sender's WhatsApp display name
message.text	string	Message text content
message.is_group	boolean	Whether the message is from a group
message.type	string	Message type (text, image, audio, etc.)
timestamp	string	ISO 8601 timestamp

API Sandbox

Test the Send Message API directly from your browser. Fill in your credentials and hit send.

Error Codes

All errors follow a consistent JSON format with an ok: false flag.

Status	Meaning	Common Cause
401	Unauthorized	Missing or invalid Bearer token
422	Validation Error	Missing required fields or invalid values
502	Bad Gateway	WhatsApp service is unreachable or session disconnected
500	Server Error	Internal error — contact support

Error Response Format

{
  "ok": false,
  "message": "Description of what went wrong."
}