especial

A websocket based communication protocol.

Usage

npm install especial

Server

const especial = require('especial')

const app = especial()

app.handle('utils.ping', (data, send, next) => {
  send('pong')
})

const server = app.listen(4000, () => {
  console.log(`Listening on port 4000`)
})

Client

const EspecialClient = require('especial/client')

const client = new EspecialClient('ws://localhost:4000')
const { data, message, status } = await client.send('utils.ping')

console.log(message) // "pong"

Protocol

Especial communicates across websockets using JSON encoded payloads. Clients emit a payload with a unique id and the server is expected to respond with a single message with the same id.

Request

Requests are structured like this:

{
  "_rid": "jki7uo9XsOEJkel3PrF_T",
  "route": "utils.ping",
  "data": {}
}

The fields are as follows:

• _rid: A unique identifier for the request
• route: A string indicating the function to execute
• data: An object containing arbitrary data for the function

Response

Responses are structured like this:

{
  "_rid": "jki7uo9XsOEJkel3PrF_T",
  "route": "utils.ping",
  "data": {},
  "message": "pong",
  "status": 0
}

• _rid: The same _rid emitted in the matching request
• route: The route requested
• data: Arbitrary data returned from the function
• message: String info about function execution
• status: Integer representing execution result, 0 indicates success

Broadcast

In addition to simple request/response communication servers may send data to clients without a request being made. This can be used to update data or provide new information.

The structure of such a message is the same as a response, with the _rid being a simple string the client may subscribe to.