API Reference

Integrate Celer Cloud into your application with our RESTful API. Send SMS, check delivery status, and manage your account programmatically.

Base URL

https://api.celerd.com/v1/

Authentication

All requests require API key authentication via the X-API-Key header.

curl -X POST https://api.celerd.com/v1/messages \ -H "X-API-Key: sk_live_your_api_key" \ -H "Content-Type: application/json" \ -d '{"to":"+1234567890","from":"CelerCloud","content":"Hello"}'

Quick Start

Get API Keys

Make a Request

Use the endpoint with your API key header

Handle Response

Parse JSON response and handle status codes

POST /messages

Send SMS

Create and send a new message to any destination worldwide.

Request Body

Field	Type	Required	Description
`to`	string	Required	Recipient phone number (E.164 format, e.g. +1234567890)
`from`	string	Required	Sender ID (alphanumeric or numeric, 1-11 characters)
`content`	string	Required	Message body (max 160 GSM-7 / 70 Unicode chars)
`callback_url`	string	Optional	Webhook URL for delivery status updates

Example Request

curl -X POST https://api.celerd.com/v1/messages \ -H "X-API-Key: sk_live_your_api_key" \ -H "Content-Type: application/json" \ -d '{ "to": "+1234567890", "from": "CelerCloud", "content": "Your verification code is: 847291" }'

Response (201 Created)

{
  "id": "msg_abc123",
  "to": "+1234567890",
  "from": "CelerCloud",
  "content": "Your verification code is: 847291",
  "status": "queued",
  "segments": 1,
  "cost": 0.015,
  "currency": "USD",
  "created_at": "2026-05-20T06:12:00Z"
}
      
      

GET /messages/{id}

Get Message Status

Retrieve delivery status for a specific message by its ID.

Response (200 OK)

{
  "id": "msg_abc123",
  "status": "delivered",
  "delivered_at": "2026-05-20T06:12:08Z",
  "cost": 0.015,
  "currency": "USD"
}
      
      

GET /messages

List Messages

Paginated list of sent messages with filtering options.

Query Parameters

Parameter	Type	Description
`page`	integer	Page number (default: 1)
`limit`	integer	Items per page (default: 50, max: 200)
`status`	string	Filter: queued / delivered / failed / pending
`date_from`	string	Start date (ISO 8601)
`date_to`	string	End date (ISO 8601)

GET /account/balance

Get Balance

Check current account balance and usage statistics.

{
  "balance": 250.75,
  "currency": "USD",
  "credit_limit": 1000.00,
  "usage_this_month": {
    "messages_sent": 12450,
    "cost": 186.75
  }
}
      
      

POST /account/keys

Manage API Keys

Create, list, or revoke API keys for your account.

POST /webhooks

Configure Webhooks

Set up webhook endpoints to receive delivery status callbacks.

Error Codes

400Bad Request — Check request body format

401Unauthorized — Verify API key is correct

429Rate Limited — Reduce request frequency

402Payment Required — Top up your balance

404Not Found — Message ID not found

500Server Error — Retry with exponential backoff

Webhook Events

Receive real-time delivery status updates via webhook callbacks.

{
  "event": "message.delivered",
  "data": {
    "message_id": "msg_abc123",
    "status": "delivered",
    "delivered_at": "2026-05-20T06:12:08Z"
  }
}
      
      