FLUX.2 Klein 4B API

# 1. Create the task. Keep the Idempotency-Key if you retry after a network error.
export IDEMPOTENCY_KEY="$(uuidgen)"
curl -X POST https://api.popnow.ai/api/v1/jobs/createTask \
  -H "Authorization: Bearer $POPNOW_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $IDEMPOTENCY_KEY" \
  -d '{
  "model": "black-forest-labs/flux-2-klein-4b/text-to-image",
  "input": {
    "prompt": "A ceramic teapot on a linen cloth, soft window light, muted palette",
    "aspect_ratio": "1:1",
    "resolution": "1k"
  }
}'

# 2. Copy data.taskId from the response, then poll until state is succeeded, failed, canceled or expired.
TASK_ID="TASK_ID_FROM_RESPONSE"
curl "https://api.popnow.ai/api/v1/jobs/recordInfo?taskId=$TASK_ID" \
  -H "Authorization: Bearer $POPNOW_API_KEY"

// Node 18+ (or any runtime with fetch). Keep the API key on your server.
const BASE = "https://api.popnow.ai/api/v1";
const headers = { Authorization: `Bearer ${process.env.POPNOW_API_KEY}` };
const sleep = (ms) => new Promise((r) => setTimeout(r, ms));

async function call(path, init = {}) {
  const res = await fetch(BASE + path, { ...init, headers: { ...headers, ...init.headers } });
  const body = await res.json();
  if (body.code !== 200) throw new Error(`${body.code} ${body.msg}`);
  return body.data;
}

const { taskId } = await call("/jobs/createTask", {
  method: "POST",
  headers: { "Content-Type": "application/json", "Idempotency-Key": crypto.randomUUID() },
  body: JSON.stringify({
    "model": "black-forest-labs/flux-2-klein-4b/text-to-image",
    "input": {
      "prompt": "A ceramic teapot on a linen cloth, soft window light, muted palette",
      "aspect_ratio": "1:1",
      "resolution": "1k"
    }
  }),
});

// Poll with backoff. A finished task may still be copying files: wait while an asset is pending.
let task;
for (let delay = 2000; ; delay = Math.min(delay * 1.5, 15000)) {
  await sleep(delay);
  task = await call(`/jobs/recordInfo?taskId=${taskId}`);
  const copying = (task.output?.assets ?? []).some((a) => a.pending && !a.unavailable);
  if (["succeeded", "failed", "canceled", "expired"].includes(task.state) && !copying) break;
}
if (task.state !== "succeeded") throw new Error(`${task.state}: ${task.errorMessage ?? "no detail"}`);

// Each asset has a signed url (no API key needed) that expires at expiresAt: save the file.
for (const asset of task.output.assets) console.log(asset.url);

import os, time, uuid, requests

BASE = "https://api.popnow.ai/api/v1"
HEADERS = {"Authorization": f"Bearer {os.environ['POPNOW_API_KEY']}"}


def call(method, path, **kwargs):
    body = requests.request(method, BASE + path, headers={**HEADERS, **kwargs.pop("headers", {})}, timeout=30, **kwargs).json()
    if body["code"] != 200:
        raise RuntimeError(f'{body["code"]} {body["msg"]}')
    return body["data"]


task_id = call(
    "POST",
    "/jobs/createTask",
    headers={"Idempotency-Key": str(uuid.uuid4())},  # reuse it if you retry
    json={
        "model": "black-forest-labs/flux-2-klein-4b/text-to-image",
        "input": {
            "prompt": "A ceramic teapot on a linen cloth, soft window light, muted palette",
            "aspect_ratio": "1:1",
            "resolution": "1k"
        }
    },
)["taskId"]

# Poll with backoff. A finished task may still be copying files: wait while an asset is pending.
delay = 2.0
while True:
    time.sleep(delay)
    task = call("GET", "/jobs/recordInfo", params={"taskId": task_id})
    assets = (task.get("output") or {}).get("assets") or []
    copying = any(a.get("pending") and not a.get("unavailable") for a in assets)
    if task["state"] in ("succeeded", "failed", "canceled", "expired") and not copying:
        break
    delay = min(delay * 1.5, 15.0)

if task["state"] != "succeeded":
    raise RuntimeError(f'{task["state"]}: {task.get("errorMessage", "no detail")}')

# Each asset has a signed url (no API key needed) that expires at expiresAt: save the file.
for asset in assets:
    print(asset["url"])