npm install express multer

import express from "express";
import multer from "multer";

const app = express();
const upload = multer({ limits: { fileSize: 12 * 1024 * 1024 } });

const API_URL = process.env.FLASH_MD_API_URL || "https://api.markpdf.tech";
const API_KEY = process.env.FLASH_MD_API_KEY;

async function pollJob(jobId) {
  while (true) {
    await new Promise((r) => setTimeout(r, 5000));
    const res = await fetch(`${API_URL}/jobs/${jobId}`, {
      headers: { "x-api-key": API_KEY },
    });
    const data = await res.json();
    if (data.status === "completed") return data.body;
    if (data.status === "failed") throw new Error(data.error);
  }
}

app.post("/convert", upload.single("file"), async (req, res) => {
  if (!req.file) return res.status(400).json({ error: "Missing file" });

  const upstream = await fetch(
    `${API_URL}/convert/raw?filename=${encodeURIComponent(req.file.originalname)}&mode=fast`,
    {
      method: "POST",
      headers: {
        "x-api-key": API_KEY,
        "content-type": req.file.mimetype,
      },
      body: req.file.buffer,
    }
  );

  if (upstream.status === 200) {
    return res.type("text/markdown").send(await upstream.text());
  }

  if (upstream.status === 202) {
    const job = await upstream.json();
    const markdown = await pollJob(job.job_id);
    return res.type("text/markdown").send(markdown);
  }

  res.status(upstream.status).send(await upstream.text());
});

app.listen(3000);