With so many SMS APIs on the market today, you might think that they all do the same thing: send text messages. But with our flexible and powerful suite of APIs, you can do more than that. Our callback systems let you receive messages and get delivery reports. You can also create user accounts, lists, lease numbers, SMS keywords, and process data included in a response to a callback.

With our SMS messaging API you can:

  • Send SMS messages
  • Receive real time delivery reports (DLR) for all messages sent
  • Receive replies and inbound SMS messages
  • Access a range of other useful messaging functions such as Lists, Virtual Numbers, Keywords & Reseller features

Our simple REST API allows you to get up and running in a matter of minutes. Start with our Quick Start Guide. If you're an advanced user, you can dive deeper into our functions and calls with our SMS API documentation. We also offer client libraries and code samples.

Current Libraries and Integrations include:

  • PHP
  • .NET
  • Ruby
  • Filemaker
  • REST Professional
  • Keap (formerly Infusionsoft)
  • Zendesk
  • Woocommerce
  • Wordpress
  • Zapier


Numbers are the Caller ID, or from field that your messages will come from. Although not mandatory for API use, we recommend users lease their own Dedicated Virtual Number to send and receive messages through the API. You can choose and lease a dedicated number in the NUMBERS section of your account. This will give you the benefit of having your own number identity that is unique to your account. You are welcome to use the free shared number pool, but will be sharing these numbers with many other small customers, and you won't be likely to get the same number each time you send a message.


All requests must be to the base URL. We provide you with an option of a response as a JSON object, or an XML string. You can choose which response you want by selecting the appropriate suffix (.json OR .xml) in your request.

Base URL: 


HTTP Methods

All requests are submitted through the HTTP POST or GET method using UTF-8 encoding and URL encoded values.


To ensure security & privacy the API only works over HTTPS protocol for all requests. Also, for your own security, If you have a website with a form which sends SMS, be sure to send the request from your server and not directly from the browser. Otherwise, you could be giving away your API secret.


All API requests require your API credentials, you will find them once logged into your account on the SETTINGS page. For security purposes, API credentials must be passed as HTTP Basic Authentication headers not as CGI parameters.


To provide the best service to all our customers we limit the number of API calls which can be made by each account to 2 calls per sec. For heavy users we can increase your throttling speed, but please contact us to discuss your requirements. If you exceed this limit we will return two indicators which you can use in your code to detect that you have been throttled. The first is the HTTP status code 429 "Too Many Requests", the second is the error code "OVER_LIMIT" in the error block of the response body.


All timestamps are in ISO8601 format, e.g. YYYY-MM-DD HH:MM:SS. The zone is always UTC.


Some responses are too large to be returned in one go so we paginate. To identify which calls use pagination look for the "page" and "max" parameters in the parameter descriptions for each API call. These calls include a "page" block in the response with two values, "count" and "number". Count tells you how many pages are available and number indicates the page number you are on. The page parameter is used to request a certain page, it defaults to 1. The max parameter is used to limit the number of results returned per page, the default is 10, the maximum is 100.

Error Reporting

Always check if your API call was successful or resulted in error. You may check the following

  • 200 OK response header. It will be 4xx if an error occurred.
  • Error->Code structure should equal to ‘SUCCESS’. Please check the table below for common error constants. Note that some API functions can return custom errors of their own (listed in appropriate document sections). Check the error->description for details, e.g. which field caused an error or which resource you don’t have access to.




AUTH_FAILED_NO_DATA 401 You have not provided auth data.
AUTH_FAILED 401 The auth data you have provided is invalid.
NOT_IMPLEMENTED 404 The method you are requesting is unsupported.
OVER_LIMIT 429 You have exceeded the request limit.
FIELD_EMPTY 400 Required field is empty.
FIELD_INVALID 400Field has invalid format (see proper format in the description).
NO_ACCESS 400 You do not have access to this resource.
KEY_EXISTS 400 The resource with this key already exists.

Free Support and Integration Assistance

We have a team of experts standing by to listen to your ideas. If you have a concept that includes SMS we can help you understand how the SMS process works and what the possibilities are for your process. We also have on hand technical experts that can give you advice at code level if you are having difficulty or require some extra expertise. Send us a ticket or talk to us on chat by clicking the icon on the bottom right.