FILE='./receipt.pdf'
SIZE=$(wc -c < "$FILE" | tr -d ' ')
SHA256=$(openssl dgst -sha256 -r "$FILE" | awk '{print $1}')
BODY=$(printf '{"method":"attachment.prepare","operation_id":"receipt-8401-prepare","params":{"purpose":"ticket","name":"receipt.pdf","mime_type":"application/pdf","size":%s,"sha256":"%s"}}' "$SIZE" "$SHA256")
SECRET='your_secret_key'
HASH=$(printf '%s%s' "$BODY" "$SECRET" | openssl dgst -sha512 -r | awk '{print $1}')

curl -X POST 'https://api.bafanglaicai88.com/public/api/multihub/v1' \
  -H 'Content-Type: application/json' -H 'X-Data-Application-Id: 1' \
  -H "X-Data-Hash: $HASH" -H "X-Data-Timestamp: $(date +%s)" \
  -H "X-Data-Nonce: $(uuidgen)" --data-binary "$BODY"

# POST every returned upload.fields entry unchanged, then add: -F "file=@${FILE};type=application/pdf"

import hashlib, json, time, uuid, requests

path = "receipt.pdf"; content = open(path, "rb").read(); secret = "your_secret_key"
payload = {"method": "attachment.prepare", "operation_id": "receipt-8401-prepare", "params": {
    "purpose": "ticket", "name": "receipt.pdf", "mime_type": "application/pdf",
    "size": len(content), "sha256": hashlib.sha256(content).hexdigest(),
}}
body = json.dumps(payload, separators=(",", ":"))
prepared = requests.post("https://api.bafanglaicai88.com/public/api/multihub/v1", data=body, headers={
    "Content-Type": "application/json", "X-Data-Application-Id": "1",
    "X-Data-Hash": hashlib.sha512((body + secret).encode()).hexdigest(),
    "X-Data-Timestamp": str(int(time.time())), "X-Data-Nonce": str(uuid.uuid4()),
}, timeout=30).json()["result"]
requests.post(prepared["upload"]["url"], data=prepared["upload"]["fields"],
              files={"file": ("receipt.pdf", content, "application/pdf")}, timeout=60).raise_for_status()

import crypto from "node:crypto";
import { readFile } from "node:fs/promises";

const content = await readFile("receipt.pdf");
const secret = "your_secret_key";
const body = JSON.stringify({
  method: "attachment.prepare",
  operation_id: "receipt-8401-prepare",
  params: {
    purpose: "ticket",
    name: "receipt.pdf",
    mime_type: "application/pdf",
    size: content.length,
    sha256: crypto.createHash("sha256").update(content).digest("hex"),
  },
});
const preparedResponse = await fetch(
  "https://api.bafanglaicai88.com/public/api/multihub/v1",
  {
    method: "POST",
    body,
    headers: {
      "Content-Type": "application/json",
      "X-Data-Application-Id": "1",
      "X-Data-Hash": crypto
        .createHash("sha512")
        .update(body + secret)
        .digest("hex"),
      "X-Data-Timestamp": String(Math.floor(Date.now() / 1000)),
      "X-Data-Nonce": crypto.randomUUID(),
    },
  },
);
const prepared = (await preparedResponse.json()).result;
const form = new FormData();
for (const [key, value] of Object.entries(prepared.upload.fields))
  form.append(key, value);
form.append(
  "file",
  new Blob([content], { type: "application/pdf" }),
  "receipt.pdf",
);
const uploadResponse = await fetch(prepared.upload.url, {
  method: "POST",
  body: form,
});
if (!uploadResponse.ok)
  throw new Error(`Upload failed: ${uploadResponse.status}`);