WhatsApp API
Getting Started with WhatsApp Business API
Set up your WhatsApp Business API account with StartMessaging in under 10 minutes. API keys, sandbox, and your first message.
Prerequisites
Before integrating with the WhatsApp Business API, you’ll need:
- A StartMessaging account — sign up free
- A Facebook Business Manager account
- A phone number that isn’t already registered with WhatsApp or WhatsApp Business app
Step 1: Create Your Account
- Visit app.startmessaging.com/signup
- Enter your business email and create a password
- Verify your email address
- Complete the onboarding wizard
Step 2: Connect Your WhatsApp Business Account
After signing in, navigate to Settings → WhatsApp → Connect Account:
- Click Connect with Facebook
- Select or create your Facebook Business Manager
- Create a new WhatsApp Business Account (WABA) or connect an existing one
- Register a phone number — you’ll receive a verification code via SMS or voice call
- Once verified, your number is live on the API
Note: StartMessaging handles the Meta app review process automatically. Most accounts are approved within 24 hours.
Step 3: Get Your API Key
Navigate to Settings → API Keys:
- Click Generate API Key
- Copy your API key — you’ll need it for all API requests
- Store it securely; never expose it in client-side code
# Your API key goes in the Authorization header
curl -X POST https://api.startmessaging.com/v1/messages \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"to": "5511999999999",
"type": "text",
"text": { "body": "Hello from StartMessaging!" }
}'
Step 4: Send a Test Message
Use the sandbox to send test messages without affecting your quality rating:
- Go to Dashboard → Sandbox
- Scan the QR code with your personal WhatsApp to opt in
- Send a test message from the sandbox console
- Check the response and delivery status
Step 5: Go Live
Once you’ve tested successfully:
- Submit your display name for review (Settings → WhatsApp → Display Name)
- Upload your business profile photo and description
- Create your first message template (required for outbound messages after 24h)
- Start sending real messages!
SDK Libraries
We offer official SDKs for the most popular languages:
| Language | Package | Install |
|----------|---------|---------|
| Node.js | @startmessaging/node | npm install @startmessaging/node |
| Python | startmessaging | pip install startmessaging |
| PHP | startmessaging/php-sdk | composer require startmessaging/php-sdk |
| Java | com.startmessaging:sdk | Maven/Gradle |
| Go | github.com/startmessaging/go-sdk | go get |
Next Steps
- Authentication — Learn about API authentication methods
- Send Messages — Send your first text, image, and template messages
- Webhooks — Receive incoming messages and status updates
FAQ
How long does account setup take? Most accounts are fully set up within 24 hours. The Facebook Business verification may take 1–3 business days for new accounts.
Can I use my existing WhatsApp number? Yes, but you’ll need to delete the WhatsApp or WhatsApp Business app from the phone first. The number can only be registered with one platform at a time.
Is there a sandbox for testing? Yes — every account includes a free sandbox where you can send test messages without affecting your quality rating or messaging limits.