The Transparent FingerprintJS Alternative & Bot Detection API.

<!-- 1. Include the 8.5KB script in your HTML <head> -->
<script src="https://cdn.botrefund.com/v1.js?id=YOUR_PROJECT_ID" async></script>

<script>
async function handleSubmit() {
  // Retrieve session-bound token (generated in <12ms)
  const token = window.__botrefundToken || await window.BotRefund?.getToken();

  // Send token along with your form or auth request
  await fetch("/api/auth/register", {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({
      email: document.getElementById("email").value,
      deviceToken: token
    })
  });
}
</script>

// 1. Install: npm install @botrefund/web
import { BotRefund } from "@botrefund/web";

// Initialize client (or pass custom first-party proxy)
const br = BotRefund.init({
  apiKey: "pk_live_your_project_id"
});

async function onRegisterSubmit(formData) {
  // Obtain token in <12ms (passive background probe)
  const deviceToken = await br.getToken();

  await fetch("/api/auth/register", {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({ ...formData, deviceToken })
  });
}

// 100% Adblocker Immunity: Route via /btr/*
import { BotRefund } from "@botrefund/web";

// Point to your Fastly, Cloudflare or Next.js route:
const br = BotRefund.init({
  apiKey: "pk_live_your_project_id",
  endpoint: "/btr" // Proxies to ingress.botrefund.com
});

// uBlock Origin & Brave Shields cannot block your own domain!
const token = await br.getToken();

// Node.js (Express / Next.js Route Handler)
import { BotRefundClient } from "@botrefund/sdk";

const botRefund = new BotRefundClient({ 
  apiKey: process.env.BOTREFUND_SECRET_KEY 
});

app.post("/api/auth/register", async (req, res) => {
  const { deviceToken, email } = req.body;

  // Verify token and retrieve detailed device signals
  const result = await botRefund.verify(deviceToken);

  if (result.is_bot || result.bot_score > 0.65) {
    return res.status(403).json({ error: "Automated access blocked" });
  }

  if (result.is_returning) {
    // Prevent multi-accounting and free trial token churning
    console.warn("Returning device detected: " + result.visitor_id);
    return res.status(409).json({ error: "Free trial already claimed" });
  }

  // Proceed to create human user account
  return createUser({ email, visitorId: result.visitor_id });
});

# Python (FastAPI / Flask)
import httpx, os

async def verify_visitor(device_token: str):
    async with httpx.AsyncClient() as client:
        resp = await client.post(
            "https://api.botrefund.com/v1/verify",
            json={"request_id": device_token},
            headers={"Authorization": f"Bearer {os.environ['BOTREFUND_API_KEY']}"}
        )
        data = resp.json()

    # Check bot flags and multi-accounting status
    if data.get("is_bot") or data.get("bot_score", 0) > 0.65:
        raise HTTPException(status_code=403, detail="Bot detected")
        
    if data.get("is_returning"):
        raise HTTPException(status_code=409, detail="Duplicate device registration")
        
    return data

# Direct REST API call via cURL
curl -X POST https://api.botrefund.com/v1/verify \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer sec_live_your_api_key" \
  -d '{
    "request_id": "req_8f31b209aef14c"
  }'