Emitter

The Node.js Emitter parses raw LLM token output and emits StreamingChunk patch operations. Runs on your server. Transport is out of scope — serialise patches however your stack requires.

Constructor


import { Emitter } from 'jsoncurrent'
 
const emitter = new Emitter(options?)

Options

Option	Type	Default	Description
`root`	`string`	`''`	Namespace prefix for all emitted paths. E.g. `'prediction'` produces paths like `prediction.title`.
`completions`	`boolean`	`true`	Emit `complete` patches when a value is fully assembled. Set `false` on high-throughput routes where `pathcomplete` events are not used.

Methods

`emitter.write(token)`

Feed a raw token from the LLM stream.


emitter.write(event.delta.text)

Param	Type	Description
`token`	`string`	Raw token string from the LLM response stream.

`emitter.flush()`

Signal end of stream. Finalises any pending state, emits complete, and resets internal state. Call this when the LLM stream closes.


emitter.flush()

`emitter.reset()`

Reset internal state without emitting complete. Useful for reusing an Emitter instance across multiple requests.

`emitter.use(fn)`


emitter.use((patch, next) => {
  next(patch)
})

See Server-side Middleware for patterns.

`emitter.on(event, fn)`

Events

`patch`

Fires for each StreamingChunk emitted. This is what you serialise and send to the client.


emitter.on('patch', (chunk: StreamingChunk) => {
  res.write(`data: ${JSON.stringify(chunk)}\n\n`)
})

`complete`

Fires when flush() is called. Signal end of stream to the client.


emitter.on('complete', () => {
  res.write('data: [DONE]\n\n')
  res.end()
})

`error`

Fires on parse errors.


emitter.on('error', (err: JsonCurrentError) => {
  console.error('Emitter error', err)
})