jr2

jr2 is an extremely lightweight JSON-RPC 2.0 compliant client and server for Javascript.

It is transport-independent, runs in client and server environments, has no dependencies.

It is tiny (< 2kB).

Installation

npm install --save jr2

You can use jr2 with module bundlers.

The jr2 npm package also includes precompiled production and development UMD builds in the dist folder. They can be used without a bundler.

The UMD builds make jr2 available as window.jr2 global variable.

jr2 works in any modern browser and Node.js.

Usage

Client

import { Client } from 'jr2'

const client = new Client()

const request = client.request('sum', [23, 42], 1)

console.log(request) // { jsonrpc: '2.0', method: 'sum', params: [23, 42], id: 1 }

Server

import { Server } from 'jr2'

const delegate = {
    sum(params, { responseWithResult }, callback) {
        const result = params.reduce((a, b) => a + b, 0)
        callback(null, responseWithResult(result))
    },
}

const server = new Server(delegate)

const request = {
    jsonrpc: '2.0',
    method: 'sum',
    params: [23, 42],
    id: 1,
}

server.handle(request, (err, response) => {
    console.log(response) // { jsonrpc: '2.0', result: -19, id: 1 }
})

Delegate

The delegate implements server methods as functions. Functions are invoked with (params, context, callback) and this is bound to the delegate.

The params argument can be an array of positional parameters or an object for named parameters.

The context argument is an object implementing two helper functions: responseWithResult(result) and responseWithError(code, message, data). These helper functions help you create a compliant response and automatically match the id of the response with the id of the related request.

The callback argument is a function. It is expected to be invoked with (err, response).

License

MIT