# Interface Type

There are two types of interface, you can choose the proper one according to your scenario and preferences.

#### REST API

REST (Representational State Transfer) is one of the most popular communication mechanism under HTTP, each URL represents a type of resource.

It is suggested to use Rest API for one-off operation, like trading and withdraw.

#### WebSocket API

WebSocket is a new protocol in HTML5. It is full-duplex between client and server. The connection can be established by a single handshake, and then server can push the notification to client actively.

It is suggest to use WebSocket API to get data update, like market data and order update.

**Authentication**

Both API has two levels of authentication:

Public API: It is for basic information and market data. It doesn't need authentication.

Private API: It is for account related operation like trading and account management. Each private API must be authenticated with API Key.