Node.js / TypeScript SDK

Use the official openai npm package in Next.js App Router, Express, or NestJS for full-duplex streaming.

npm install openai

Next.js 15 App Router streaming route

// app/api/chat/route.ts
import OpenAI from 'openai';

const openai = new OpenAI({
  apiKey: process.env.CALLAI_API_KEY,
  baseURL: 'https://api.callaiapi.com/v1',
});

export async function POST(req: Request) {
  const { messages } = await req.json();

  const response = await openai.chat.completions.create({
    model: 'claude-3-7-sonnet',
    messages,
    stream: true,
  });

  const encoder = new TextEncoder();
  const readable = new ReadableStream({
    async start(controller) {
      for await (const chunk of response) {
        const text = chunk.choices[0]?.delta?.content || '';
        controller.enqueue(encoder.encode(text));
      }
      controller.close();
    },
  });

  return new Response(readable, {
    headers: { 'Content-Type': 'text/plain; charset=utf-8' },
  });
}

💡AbortController client cancel

Bind an AbortSignal on the client request. When the user hits Stop, abort disconnects from CallAI immediately and stops billing.

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