API call

For XML:
Successfull XML response:<?xml version="1.0" encoding="UTF-8"?> <response> ... </response>
Error XML response:<?xml version="1.0" encoding="UTF-8"?> <error> <code>ERROR_CODE</code> <text>Error description</text> </error>

Successfull JSON response:{ response: { ... } }
Error JSON response:{ error: { code: "ERROR_CODE", text: "Error description" } }

For JavaScript with callback:
Successfull JavaScript response:MyCallbackFunc({ response: { ... } });
Error JavaScript response:MyCallbackFunc({ error: { code: "ERROR_CODE", text: "Error description" } });

api_id - go to section My API keys and create new API key.
api_sign - read this how to calculate api signature
api_sid - session identificator, to obtain it call API "/api/auth".

You can pass all parameters via GET or POST method.

If you use the cookies in your request, you can omit parameter "api_sid", and pass cookie "app_sid_" + api_id (from /api/auth) instead it.