AI Token Stream

Problem

A chat endpoint emits newline-delimited chunks and the view must stop reading once it receives completion.

Solution

Use read() with parse: 'ndjson'; leaving the loop aborts the active response immediately.

import { createCourier } from '@vielzeug/courier';

type ChatChunk = { done: boolean; delta: string };

const courier = createCourier({ baseUrl: 'https://api.example.com' });
let message = '';

for await (const chunk of courier.read<ChatChunk>('/chat', {
  body: { prompt: 'Explain cached queries briefly.' },
  method: 'POST',
  parse: 'ndjson',
})) {
  message += chunk.delta;
  if (chunk.done) break;
}
console.log(message);

Pitfalls

• parse: 'ndjson' requires one JSON value per newline; omit it for text chunks.
• Configure timeout explicitly for a bounded long-running response.
• Recreate a stream only when reconnecting or retrying is safe for the endpoint.

Related

• HTTP Streaming
• Real-time Events