Heli + Vercel AI SDK

Server Route (Next.js)

import { createOpenAI } from "@ai-sdk/openai";
import { streamText } from "ai";

const heli = createOpenAI({
  baseURL: "https://getheli.ru/v1",
  apiKey: process.env.HELI_API_KEY,
});

export async function POST(req: Request) {
  const { messages } = await req.json();
  const result = streamText({
    model: heli("openai/gpt-4.1-mini"),
    messages,
  });
  return result.toDataStreamResponse();
}

Node.js + Heli