curl --fail-with-body -sS -X POST 'https://api-testnet.lumeus.dev/billing/purchases' \
  -H "Authorization: Bearer $LUMEUS_API_KEY" \
  -H 'Idempotency-Key: purchase-0001-2026-10-22' \
  -H 'Content-Type: application/json' \
  -d '{"offer_version":"prepaid-2026-10"}'

// Node 18+ (ES module)
const res = await fetch('https://api-testnet.lumeus.dev/billing/purchases', {
  method: 'POST',
  headers: {
    Authorization: `Bearer ${process.env.LUMEUS_API_KEY}`,
    'Idempotency-Key': 'purchase-0001-2026-10-22',
    'Content-Type': 'application/json',
  },
  body: JSON.stringify({
    "offer_version": "prepaid-2026-10"
  }),
});
console.log(res.status, JSON.stringify(await res.json(), null, 2));

import json
import os

import requests

res = requests.post(
    "https://api-testnet.lumeus.dev/billing/purchases",
    headers={"Authorization": f"Bearer {os.environ['LUMEUS_API_KEY']}", "Idempotency-Key": "purchase-0001-2026-10-22"},
    json={
        "offer_version": "prepaid-2026-10"
    },
    timeout=30,
)
print(res.status_code, json.dumps(res.json(), indent=2))

{
  "id": "00000000-0000-4000-8000-000000000000",
  "offer_version": "prepaid-2026-10",
  "kind": "payment",
  "state": "open",
  "checkout_url": "https://checkout.stripe.com/c/pay/cs_test_0000",
  "checkout_expires_at": "2026-10-23T09:15:04Z",
  "payment_status_url": "/billing/status"
}

{
  "id": "00000000-0000-4000-8000-000000000000",
  "offer_version": "prepaid-2026-10",
  "kind": "payment",
  "state": "prepared",
  "checkout_url": "",
  "checkout_expires_at": null,
  "payment_status_url": "/billing/status"
}

{
  "code": "invalid_request",
  "error": "Idempotency-Key must be 8 to 128 printable ASCII characters without spaces, sent once",
  "request_id": "req_6f1c2a9b0e4d4c7a8b3f5e21"
}

{
  "code": "unauthorized",
  "error": "missing credentials",
  "request_id": "req_6f1c2a9b0e4d4c7a8b3f5e21"
}

{
  "code": "forbidden",
  "error": "this API key is read-only; use a full-access key or a signed-in session",
  "request_id": "req_6f1c2a9b0e4d4c7a8b3f5e21"
}

{
  "code": "method_not_allowed",
  "error": "method GET is not allowed on /billing/purchases; allowed: POST",
  "request_id": "req_6f1c2a9b0e4d4c7a8b3f5e21"
}

{
  "code": "conflict",
  "error": "purchase key already binds another offer",
  "request_id": "req_6f1c2a9b0e4d4c7a8b3f5e21"
}

{
  "code": "rate_limited",
  "error": "rate limit exceeded",
  "request_id": "req_6f1c2a9b0e4d4c7a8b3f5e21"
}

{
  "code": "unavailable",
  "error": "prepaid purchases are not enabled",
  "request_id": "req_6f1c2a9b0e4d4c7a8b3f5e21"
}