Specification

Brief

JSON-RPC is a lightweight, stateless protocol for creating a remote procedure call (RPC) style API. We support several types of data and commands, with the possibility of notification (information sent to the server does not require a response) and multiple calls.

The request object includes the following properties:

• jsonrpc — will always be "2.0", indicates the protocol version.
• method — the name of the method to be called.
• params — optional property, load to the call (method arguments).
• id — optional property, unique call identifier. If you want to get the value from the called function, you must generate id on the client-side. When answering, you can understand which call the answer came by matching the response’s id.

{
    "jsonrpc":"2.0",
    "method":"ping",
    "params":[],
    "id":1
}

Note. If you did not send id, then this means that you are not interested in the answer, and you will not receive anything from the server. Such a call is called a notification.

An answer can have the following properties:

• jsonrpc — will always be "2.0", indicates the protocol version.
• result — response body (return value of the method).
• id — unique identifier of the response. It is needed so that the client can match to which request he received a response.
• error — in case of a mistake, you will get an error field containing a code and a human-readable description of the error instead of the result.

{
    "jsonrpc": "2.0",
    "id": 1,
    "result": "pong"
}

Official source for JSON-RPC 2.0 Specification. You can ask clarifying questions to the guys from the JSON-RPC Google group.