Bun script: submit a Wan 3.0 video job, poll it and save clip.mp4

A Bun script needs no packages: fetch the POST /v1/videos endpoint with model: "wan-3.0", poll the polling_url until status leaves pending and in_progress, then write the response of GET /v1/videos/{id}/content?index=0 with Bun.write. The 5-second 480p test below costs $0.3125 on Sume (Video Router, read 2026-10-05).

What is the full script?

Run it with bun run clip.ts after exporting SUME_API_KEY. Bun supports top-level await and Bun.sleep.

const base = "https://api.sume.com/v1/videos";
const headers = {
  Authorization: `Bearer ${process.env.SUME_API_KEY}`,
  "Content-Type": "application/json",
};
const res = await fetch(base, {
  method: "POST",
  headers,
  body: JSON.stringify({
    model: "wan-3.0",
    prompt: "A kite rises over a grassy hill, wind in the grass",
    duration: 5,
    resolution: "480p",
    aspect_ratio: "16:9",
  }),
});
const job = await res.json();
let status = job.status;
while (status === "pending" || status === "in_progress") {
  await Bun.sleep(10_000);
  const poll = await (await fetch(job.polling_url, { headers })).json();
  status = poll.status;
  console.log(status);
}
if (status === "completed") {
  const video = await fetch(`${base}/${job.id}/content?index=0`, { headers });
  await Bun.write("clip.mp4", video);
}

Which Wan 3.0 options can I change?

Wan 3.0 accepts 2 to 30 seconds, 480p, 720p or 1080p, auto, adaptive, 16:9, 4:3, 1:1, 3:4 and 9:16 aspect ratios, and first_frame, last_frame and reference inputs. It does not take seed or size: those return 400 unsupported_parameter.

How do I make it safe to re-run?

Add an Idempotency-Key header to the submit call so a re-run returns the original job. The same idea in other runtimes is covered in the Swift version, and the Wan prompt wording is in the Wan 3.0 prompt guide.