How to Build a Vehicle Lookup App Without Building a Database

				
					import express from "express";
const app = express();
const VIN_PATTERN = /^[A-HJ-NPR-Z0-9]{17}$/;
function toVehicle(d) {
  return {
    vin: d.intro.vin,
    year: Number(d.basic.year),
    make: d.basic.make,
    model: d.basic.model,
    trim: d.basic.trim,
    body: d.basic.body_type,
    doors: d.basic.doors,
    seats: d.basic.seating_capacity,
    engine: d.engine.engine_description,
    cylinders: d.engine.cylinders,
    drive: d.drivetrain.drive_type,
    fuel: d.fuel.fuel_type,
    builtIn: d.manufacturer.country,
  };
}
app.get("/api/vin/:vin", async (req, res) => {
  const vin = req.params.vin.trim().toUpperCase();
  // Cheap check before spending a credit: 17 characters, no I, O or Q
  if (!VIN_PATTERN.test(vin)) {
    return res.status(400).json({ error: "Invalid VIN format" });
  }
  const upstream = await fetch(
    `https://api.vehicledatabases.com/vin-decode/${vin}`,
    { headers: { "x-authkey": process.env.VEHICLE_DATABASES_KEY } }
  );
  const body = await upstream.json().catch(() => null);

  if (!upstream.ok || body?.status !== "success") {
    if (upstream.status === 400) {
      return res.status(404).json({ error: "No record for this VIN" });
    }
    if (upstream.status === 422 || upstream.status === 429) {
      return res.status(429).json({ error: "Too many requests, try again shortly" });
    }
    // 401 and everything else is your problem, not the user's: log and alert
    return res.status(502).json({ error: "Lookup failed" });
  }
  res.json(toVehicle(body.data));
});
app.listen(3000);