A zero-dependency node stream for writing Server-Sent Events.

npm install ssestream

Or:

yarn add ssestream

In a (req, res) handler for a request event, Express #get route or similar:

const SseStream = require('ssestream')

function (req, res) {
  const sse = new SseStream(req)
  sse.pipe(res)
  
  const message = {
    data: 'hello\nworld',
  }
  sse.write(message)
}

Properties on message:

• data - String or object, which gets turned into JSON
• event - (optional) String
• id - (optional) String
• retry - (optional) number
• comment - (optional) String

The SseStream#writeMessage(message) method is a type-safe alias for SseStream#write(message).