route.js

import { NextResponse } from 'next/server';
import Replicate from 'replicate';

const replicate = new Replicate({
  auth: process.env.REPLICATE_API_TOKEN,
});

// Prevent Next.js / Vercel from caching responses
// See https://github.com/replicate/replicate-javascript/issues/136#issuecomment-1728053102
replicate.fetch = (url, options) => {
  return fetch(url, { ...options, cache: "no-store" });
};

// In production and preview deployments (on Vercel), the VERCEL_URL environment variable is set.
// In development (on your local machine), the NGROK_HOST environment variable is set.
const WEBHOOK_HOST = process.env.VERCEL_URL
  ? `https://${process.env.VERCEL_URL}`
  : process.env.NGROK_HOST;

export async function POST(request) {
  if (!process.env.REPLICATE_API_TOKEN) {
    throw new Error(
      'The REPLICATE_API_TOKEN environment variable is not set. See README.md for instructions on how to set it.'
    );
  }

  const { prompt } = await request.json();

  const options = {
    version: '8beff3369e81422112d93b89ca01426147de542cd4684c244b673b105188fe5f',
    input: { prompt }
  }

  if (WEBHOOK_HOST) {
    options.webhook = `${WEBHOOK_HOST}/api/webhooks`
    options.webhook_events_filter = ["start", "completed"]
  }

  const prediction = await replicate.predictions.create(options);

  if (prediction?.error) {
    return NextResponse.json({ detail: prediction.error }, { status: 500 });
  }

  return NextResponse.json(prediction, { status: 201 });
}