REST API

A REST API (Representational State Transfer Application Programming Interface) is a standardized interface for communication between software systems over HTTP. It enables programmatic access to services like messaging platforms – structured, scalable, and platform-independent.

What is a REST API?

A REST API is a programming interface that allows applications to communicate with each other using standardized HTTP requests. REST stands for "Representational State Transfer" – an architectural style built on existing web technologies: HTTP methods (GET, POST, PUT, DELETE), URLs as resource addresses, and JSON or XML as data formats.

In a messaging context, this means: your software sends a POST request to a URL like https://api.sendseven.com/v1/messages with JSON data (recipient, message text, channel), the API processes the request, and returns a response (e.g., "Message sent, ID: 12345").

REST APIs are stateless – each request contains all necessary information. Authentication is handled via API keys, OAuth, or Bearer tokens. Responses use standard HTTP status codes (200 OK, 401 Unauthorized, 500 Server Error) for consistent error handling.

Why are REST APIs Important for Messaging?

REST APIs make messaging platforms programmatically accessible – no manual operation, full automation:

  • System integration – CRM, ERP, and e-commerce platforms send messages automatically
  • Automation – Order confirmations, shipping notifications, appointment reminders
  • Scalability – Process thousands of messages in parallel
  • Platform-independent – Any programming language (Python, Node.js, PHP, Java) can make HTTP requests
  • Industry standard – Developers know REST; no proprietary protocols to learn

Unlike graphical interfaces, REST APIs enable event-driven communication: "When an order is placed, send a WhatsApp confirmation." This powers real-time workflows without manual intervention.

Practical Example

An online shop wants to send a WhatsApp confirmation after every order. The shop uses the SendSeven REST API:

POST https://api.sendseven.com/v1/messages

Request body (JSON):

{
  "to": "+491701234567",
  "channel": "whatsapp",
  "text": "Thanks for your order #12345! We will ship your package tomorrow."
}

The API authenticates the request via the API key in the header, validates the data, routes the message to WhatsApp's Cloud API, and returns a response:

{
  "messageId": "msg_abc123",
  "status": "sent",
  "timestamp": "2026-02-19T14:32:00Z"
}

The shop stores the message ID to track delivery status via webhooks later. Everything is automated – no manual steps required.

SendSeven REST API

The SendSeven REST API is fully documented, developer-friendly, and modern: OpenAPI spec (Swagger), interactive documentation with try-it-out functionality, and code examples in all major languages.

Unified endpoint: /v1/messages works for WhatsApp, Telegram, Email, SMS, Messenger, Instagram, and Live Chat – one request format for all channels. Webhook support with 21 real-time event types across messages, emails, conversations, contacts, and link tracking -- see the Webhook glossary entry for the full list.

Authentication via API key (simple) or OAuth 2.0 (enterprise). See the API Authentication Guide for setup instructions. Rate limiting is transparently documented. GDPR-compliant, EU-hosted. Full API docs: docs.sendseven.com