In order to run this code, you must install the OpenAI SDK by running npm i openai.
npm i openai
import OpenAI from "openai"; export default { async fetch(request, env, ctx): Promise<Response> { const openai = new OpenAI({ apiKey: env.OPENAI_API_KEY }); // Create a TransformStream to handle streaming data let { readable, writable } = new TransformStream(); let writer = writable.getWriter(); const textEncoder = new TextEncoder(); ctx.waitUntil((async () => { const stream = await openai.chat.completions.create({ model: 'gpt-4o-mini', messages: [{ role: 'user', content: 'Tell me a story' }], stream: true, }); // loop over the data as it is streamed and write to the writeable for await (const part of stream) { writer.write(textEncoder.encode(part.choices[0]?.delta?.content || '')); } writer.close(); })()); // Send the readable back to the browser return new Response(readable); },} satisfies ExportedHandler<Env>;