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WhatsApp API Overview
The WhatsApp API lets you send and receive WhatsApp messages programmatically at scale. You can connect multiple WhatsApp phone numbers (sessions), send text, images, documents, and template messages, manage groups, and receive real-time delivery events via webhooks.
Base URL
All WhatsApp API requests are made to:
https://sendapi.co/v1/whatsappAuthentication
All requests require a Bearer token in the Authorization header:
Authorization: Bearer sk_live_YOUR_API_KEYEndpoints
| Method | Endpoint | Description |
|---|---|---|
POST | /v1/whatsapp/sessions | Create a new WhatsApp session |
GET | /v1/whatsapp/sessions | List all sessions |
GET | /v1/whatsapp/sessions/{id} | Get a single session |
DELETE | /v1/whatsapp/sessions/{id} | Delete a session |
GET | /v1/whatsapp/sessions/{id}/qr | Get QR code for pairing |
POST | /v1/whatsapp/send | Send a message |
POST | /v1/whatsapp/send-bulk | Send bulk messages |
GET | /v1/whatsapp/messages | List message history |
GET | /v1/whatsapp/messages/{id} | Get a single message |
POST | /v1/whatsapp/groups | Create a group |
GET | /v1/whatsapp/groups | List all groups |
PUT | /v1/whatsapp/groups/{id} | Update a group |
GET | /v1/whatsapp/contacts | List contacts |
GET | /v1/whatsapp/contacts/{phone}/check | Check if a number is on WhatsApp |
Plan Limits
WhatsApp is governed by your plan's session count and overall API rate limit (see Rate Limits).
| Plan | WhatsApp sessions | API requests / min |
|---|---|---|
| Starter | 1 | 60 |
| Growth | 3 | 300 |
| Business | 10 | 1,000 |
| Enterprise | Unlimited | 2,000 |
Anti-ban Protection
WhatsApp's own anti-spam logic may temporarily throttle your session if you send too quickly. SendAPI's bulk endpoint already paces deliveries between recipients. For direct sends from your own code, keep volume modest — there's no hard per-session limit at the API layer, but burst traffic can get your phone number flagged by WhatsApp itself.
Message Types
The WhatsApp API supports the following message types:
| Type | Description |
|---|---|
text | Plain text message with optional formatting |
image | Image message (URL or base64) |
video | Video message |
audio | Audio message |
document | File attachment with filename |
location | Geographic location (lat/lng + label) |
contact | vCard contact |
template | Pre-approved Meta Business template |
interactive | Buttons or list messages |
poll | Poll with multiple options |
Session Lifecycle
A WhatsApp session represents a connected phone number. Sessions go through the following states:
PENDING → CONNECTED → DISCONNECTED → (reconnecting) → CONNECTED- PENDING: Session created, waiting for QR code scan
- CONNECTED: Phone paired, messages can be sent
- DISCONNECTED: Session lost, auto-reconnect in progress
Next Steps
- Manage Sessions — Connect your first WhatsApp number
- Send Messages — Start sending messages
- Webhook Events — Receive real-time delivery updates