page runs from an authorised domain c. page provide valid auth token/signature THEN page can use the WeChat JS API (via wx./jWeixin. object) When the page opens, you have to wait for the browser to call: wx.ready(function(){ // ... }); then you can start making calls to the WeChat JS API. wx.checkJsApi({ jsApiList: ['chooseImage'] // List of JS APIs to be checked. success: function(res) { // Key-value pairs, false for unavailable APIs // Example: // { "checkResult": {"chooseImage":true}, // "errMsg":"checkJsApi:ok" } }); Each API calls, as a result of its invocation, some callbacks: • success: ok • fail: ko • complete: called no matter what Some API have also: • cancel: if the API displays an UI with buttons and the user tap cancel • trigger: called when some menu items are clicked