Registering for an API Key
Once registered, an API key is automatically generated and is located under User area > Settings, on the bottom right. The API key must be attached to request via the api parameter (see full example below).
Sending a request for shortening a URL
To send a request, you must use the following format where the variables api and url are required. In the example below, the URL of the demo is used but you should use your own domain name. To request a custom alias, simply add &custom= at the end.
The response will be encoded in JSON format (default). This is done to facilitate cross-language usage. The first element of the response will always tell if an error has occurred (error: 1) or not (error: 0). The second element will change with respect to the first element. If there is an error, the second element will be named “msg”. which contains the source of error, otherwise it will be named “short” which contains the short URL. (See below for an example)
// An error has occurred
"msg":"Please enter a valid email"
Using plain text format
You can request the response to be in plain text by just adding &format=text at the end of your request. This will return just https://craz.ee/DkZOb instead of the JSON response. Note that if an error occurs, it will not output anything. The plain text format function is especially helpful if you are using a 3rd party Twitter app like Tweetbot where it allows you to use custom URL Shortener.
Using the API in PHP
To use the API in your PHP application, you have to send a GET request through file_get_contents or cURL: Both are reliable methods. You can see a sample code below using file_get_contents.
// Using JSON Response
// Using Plain Text Response