Node.js integration

Block disposable emails in Node.js

You're running a Node.js app and fake signups keep getting through. Add one request to your signup route and Fidro checks the email and IP before the account exists.

How it works

Send the user's email and IP to Fidro with fetch, which ships with Node 18 and later. Fidro checks the address, the network and what it has already seen from them, then answers allow, challenge or block. No SDK and no extra packages.

One fake signup can look perfectly normal. Five from the same IP in an hour don't. Send event and user_id with each call and Fidro remembers, so it catches the pattern as well as the person. You get a score from 0 to 100 and one answer: allow, challenge or block.

1. Install what you need

# Node 18+ has fetch built in. On older versions:
npm install node-fetch

You'll also need an API key. Sign up free and you'll have one in a minute, no card needed.

2. Check every signup

Send the email and IP to POST /api/validate. Fidro checks for disposable domains, missing mail servers, VPNs, proxies and Tor, and answers allow, challenge or block. Let the allows straight in, ask the challenges to confirm their email, and turn the blocks away.

const FIDRO_API_KEY = process.env.FIDRO_API_KEY;

async function checkSignup(email, ip) {
  const response = await fetch("https://fidro.io/api/validate", {
    method: "POST",
    headers: {
      Authorization: `Bearer ${FIDRO_API_KEY}`,
      "Content-Type": "application/json",
    },
    body: JSON.stringify({ email, ip, event: "signup" }),
  });

  if (!response.ok) {
    throw new Error(`Fidro API error: ${response.status}`);
  }

  return response.json();
}

// Usage
checkSignup("test@example.com", "8.8.8.8").then((result) => {
  console.log("Risk score:", result.risk_score);         // 0 to 100
  console.log("Recommendation:", result.recommendation); // allow, challenge or block

  if (result.recommendation === "block") {
    // Refuse the signup
  }
});

3. Look up an IP

Just want to know where a request came from? GET /api/ip/{ip} returns the country, city, ISP and network, without scoring. The VPN, proxy and Tor flags come from /api/validate, under data.checks.

const FIDRO_API_KEY = process.env.FIDRO_API_KEY;

async function lookupIp(ip) {
  const response = await fetch(`https://fidro.io/api/ip/${ip}`, {
    headers: { Authorization: `Bearer ${FIDRO_API_KEY}` },
  });

  if (!response.ok) {
    throw new Error(`Fidro API error: ${response.status}`);
  }

  const result = await response.json();
  console.log("Country:", result.location.country_name);
  console.log("ISP:", result.location.isp);
  return result;
}

// Usage
lookupIp("8.8.8.8").catch((err) => console.error(err));

Want to see real results first? Try any address in the free IP checker.

Next steps

The API reference has every field. The free checker shows you real results. And if you're weighing up alternatives, the comparisons are honest about where others fit.

API Documentation Free email checker Compare Fidro

Frequently Asked Questions

How do I add fraud detection to Node.js?

Send a POST request to https://fidro.io/api/validate from your signup route with the user's email and IP. Fidro returns a risk score from 0 to 100 and one recommendation: allow, challenge or block. It takes a few minutes to wire up.

Does Fidro have a Node.js SDK?

You don't need one. Fidro is a plain REST API, so Node's built-in fetch (Node 18 and later) or node-fetch on older versions is all it takes: send JSON, read JSON.

Is Fidro free to use with Node.js?

Yes. The free plan covers 200 validations a month with no credit card, and it works with any Node.js app, whether you use Express, Fastify, Hapi or plain Node.

What should I do when Fidro says challenge?

Ask for something a real person will happily do and a script won't: confirm the email address, solve a CAPTCHA, or wait for a quick manual review. Save outright blocks for the clear cases.

Start catching bad signups in the next 5 minutes

Create your account, grab your API key, and send your first request. Free plan with 200 validations/month. No credit card. Cancel anytime.

Start for free Read the docs