When​ ​you​ ​have integrated​ ​server​ ​SDK​ ​and​ ​run​ ​the​ ​demo, a ​simplified​ ​ version of captcha has already been integrated.​ ​We​ ​also​ ​provide​ ​other​​ configuration parameters​ ​and​ ​APIs except the demo presented.​ This session will explain the configuration and APIs of client.​

Development environment

Item Description
Compatibility IE 6+, Chrome, Firefox, Safari, Opera, mainstream mobile browsers and Webview of iOS and Android


Item Link
Data communication flow chart Data communication flow chart
API documentation API example


Prerequisite: Please ensure that you have finished the server integration (Server integration docs)

  1. Import captcha initialization function initGeetest through the following example.(Download gt.js: https://github.com/GeeTeam/gt3-node-sdk/blob/master/demo/static/libs/gt.js)
<script src="gt.js"></script>

The captcha initialization should be finished after the web page has been loaded. Otherwise, the captcha cannot collect the behavioral data in this web page, which will lead to the failure of some defense strategies.

Note: the gt.js is used to load the corresponding JS libraries. Each server SDK contains a copy of gt.js. Please copy this file to the project if you want to use it.

  1. Initialization

    url: "API1 url(Refer to server integration docs)",
    type: "get",
    dataType: "json",
    success: function (data) {
    //Ensure data.gt, data.challenge and data.success are not null
    // The following data are from server side
    gt: data.gt,
    challenge: data.challenge,
    offline: !data.success,
    new_captcha: true
    }, function (captchaObj) {
    // Call instance method captchaObj

Note: For multiple CAPTCHAs on the same page, each CAPTCHA requires initilization from calling initGeeTest() method.


The parameter configuration refers to the config object (key-value pairs) which is passed during the captcha verification. It is the first parameter passed when calling the initGeetest().

The following parameters are required to be configured.

Parameter Type Description
gt String CAPTCHA ID. You can get it from the dashboard.
challenge String ID of CAPTCHA request, generated when server SDK sends a request to GeeTest server.
offline Boolean Status of GeeTest API server, which indicates whether GeeTest server is uptime or downtime (i.e. in Failback mode)
new_captcha Boolean Refers to the CAPTCHA version (V3.0 or V2.0) and could be used in Failback mode. The return value true refers to V3.0.

You only need to pass these parameters which are returned from server SDK as shown in the Demo.

Please check the API referer for the optional configuration parameters.