An API is a description of the methods that one computer uses to communicate with another one.
Blockchain APIs are useful for managing wallets, viewing and analyzing transaction notes, and getting all changes in the state of the network in real-time.
Main API directions
The main use of API can be divided into two categories:
- to work with cryptocurrencies
- to work with other blockchain devices
The APIs related to cryptocurrency is divided into three categories:
Crypto Wallet API allows applications to access and manage funds in wallets. You don’t have to maintain your node and wallet to transfer and receive transactions. There is no need for confidential keys.
Block Explorer API with the blockchain explorer helps to analyze transactions’ data (money/data) and get access to important blockchain statistics.
Crypto Exchange API is an analytical tool used in financial and trading applications. Crypto Exchange API is convenient for crypto banks, loans, and cryptocurrency market research, and various trading bots software. It is simply irreplaceable for all financial and technical applications.
API methods
API is responsible for communication with the end-user and is responsible for the stable interaction with applications participating in the exchange of data. At this level, the Blockchain APIs use several popular methods: REST, JSON-RPC, and WebSocket.
A REST API is a regular HTTP session that is structured as a finite series of requests and responses. In other words, it is a one-way action: the server cannot tell the client whether something is happening. The client has to request the changed events. After the client completes the request, the connection is closed and the HTTP session is not saved. REST transfers the protocol details (headers + URL + body + status code + success / failure) to the application layer over HTTP. This close relationship limits its usefulness in modern systems that provide broad-spectrum APIs (HTTP, HTTP2, Websocket, IPC, MQTT, etc.)
WebSocket is a method that provides bidirectional, full-duplex communication over a persistent TCP connection. The WebSocket standard was adopted in 2011 and most modern web browsers support it.
A WebSocket session is much more arbitrary and can represent anything. A full-duplex and persistent connection is established between the client and the server. The connection remains open throughout the entire life of the application as opposed to the request and response.
The two-way simultaneous communication is possible since the connection is full-duplex. The server can initiate communication and transmit some of the client’s data.
The WebSocket API is used to retrieve market data and allows us to interact with the trading system in real-time. JSON messages and trade messages are formed in the FIX standard for naming fields and message types. Each data type is provided through a dedicated channel. Customers must subscribe to all relevant channels from which they want to receive real-time updates.
The WebSocket API limits the maximum number of concurrent connections to protect against misuse (such as DDoS attacks).
The WebSocket API allows multiple channel subscriptions over a single WebSocket connection (for example, subscribing to all available market data for an XBT / USD currency pair over a single connection). All available market data for all currency pairs can be transmitted without reaching the WebSocket connection limit.
WebSocket is the best solution if you track updates in your crypto wallet in real-time. It is more convenient to connect the platform’s API push notifications to your mobile device to receive any notifications instantly.
The REST API can be used with the WebSocket API for a variety of purposes.
For example, the WebSocket API can be used to provide real-time notifications, while the REST API will manage your resources.
API providers
Developers don't need to use complex software to integrate the blockchain into their products, maintain wallets, or download terabytes of raw blockchain information. All you need to do is choose a blockchain API provider that will keep everything up and running 24/7 and at a reasonable price. Even a novice coder who has no practical experience in creating blockchain-related programs will be able to easily, quickly, and efficiently apply APIs in their line of business.
GetBlock is a service with the ability to connect to the main nodes of the blockchain of the most popular cryptocurrencies using JSON-RPC, REST, and WebSockets. It will help you to grow your business with the help of blockchain. You’ll receive a personal free API key with all the settings you need right after registration on the GetBlock platform.