Keep fake signups and stolen cards
out of your SaaS.
One API call scores the email, the IP and the network, remembers who it has seen, and tells you to allow, challenge or block. When the payment arrives, it scores that too.
Free plan with 200 validations/month. No credit card required.
- 50,000+
- Disposable email domains, updated daily
- VPN, proxy, Tor
- Plus datacenter IPs, signup bursts and impossible travel
- 25+
- Risk factors scored on every Stripe payment
- Under 200ms
- Average response, safe to call inline
Try it: check any email for fraud risk
See how Fidro scores an email address for risk. The full API also checks IP, geolocation, and Stripe payment data. Try our email checker or VPN detector for more.
Emails you test are checked in real time and never stored.
Free demo limited to 1 request per 30 seconds per IP. Previously tested emails are cached for 24 hours. Sign up to start on the free plan with 200 validations/month.
Abusers cost you twice: at signup, then at checkout
First they burn your free tier with disposable emails behind a VPN. Then the ones that reach checkout with a stolen card cost you the product, the revenue, and a $15-100 dispute fee on top.
- Under Visa's 2026 VAMP rules, dispute rates above 1.5% trigger $8-per-dispute fees and account reviews. Processors like Stripe enforce even tighter limits.
- Stolen cards processed through Stripe become disputes you can't win and revenue you can't recover.
- Fake accounts also skew your metrics. Activation, retention and conversion are all measured against users who were never real.
The average chargeback costs merchants $190 once you count the fee, the lost product and the time spent fighting it. Ten a month is $1,900 you never see. How the VAMP thresholds work. (Source: Chargebacks911)
One API call. Every signal. One answer.
Add one request to your signup flow. Fidro checks the email, the IP, the network and the location, counts what it has already seen from them, then returns a score from 0 to 100 with a clear allow, challenge or block recommendation.
- Check email validity, disposable domains, VPNs, proxies, Tor and datacenter IPs in a single call.
- Tell it the event and the user and it flags the third signup from one IP, the login from a new country, the user in two countries within an hour.
- And when the payment arrives, score it against 25+ chargeback risk factors too.
POST /api/validate
{
"email": "jd8842@tempmail.plus",
"ip": "185.220.101.4",
"event": "signup"
}
Response:
{
"risk_score": 100,
"recommendation": "block",
"message": "High risk signup detected due to: disposable email
provider, Tor network. We recommend blocking this
signup. Velocity: ip signup burst.",
"data": {
"checks": {
"disposable_email": true,
"tor": true,
"ip_signup_burst": true
},
"velocity": { "ip_signups_1h": 3 },
"anomalies": [
{ "code": "ip_signup_burst", "severity": "high",
"detail": "3 signups from 185.220.101.4 in the last hour." }
]
}
}What is Fidro?
Fidro is a fraud detection API for developers. A single request scores an email address and an IP against disposable-email, VPN, proxy, Tor, datacenter, blocklist and geolocation checks, and returns one risk score from 0 to 100 with an allow, challenge or block recommendation. Tell it what is happening (a signup, a login, a checkout) and who it is, and it also remembers the call, so the third signup from one IP in an hour or a user appearing in two countries within an hour is flagged as an anomaly. Where single-signal vendors return one attribute and leave the judgement to you, Fidro returns a decision. It also scores Stripe transactions at payment time against 25+ risk factors, so one integration covers both signup fraud and chargebacks.
50,000+
Disposable email domains tracked and updated daily
25+
Risk factors evaluated per Stripe transaction
< 200ms
Average API response time for real-time validation
Live today
—
API calls today
—
Emails validated
—
Risks detected
—
Requests right now
One integration instead of three vendors
Stop stitching together Stripe fraud tools, email validators, and IP lookup services. Fidro runs all checks in a single request and returns one risk score.
Refund high-risk payments before they become chargebacks
Fidro listens to your Stripe webhooks and scores every completed payment against 25+ chargeback risk factors: card-country mismatches, geolocation, disposable emails, transaction velocity, and the same card popping up across multiple accounts. High-risk charges get a refund recommendation while a refund is still just a refund, not a dispute counting against your VAMP ratio.
Already using Stripe Radar? Keep it. Radar scores the card at payment time. Fidro scores the email, IP, and signup behavior around it, then keeps watching after the charge. How Radar and Fidro fit together →
Webhook: payment_intent.succeeded
{
"risk_score": 78,
"recommendation": "refund",
"risk_message": "HIGH RISK - Disposable email, card
used across multiple accounts",
"checks": {
"disposable_email": true,
"card_reuse": true,
"high_value_transaction": true
}
}Risk score every signup
Every signup and payment gets a 0-100 score with an allow/challenge/block recommendation, so your code decides in one if statement instead of a manual review queue.
Block disposable emails
Detect 50,000+ disposable email domains at signup. Stop free tier abuse and fake accounts before they enter your system.
Detect VPNs and proxies
Flag VPNs, proxies, Tor nodes, and datacenter IPs. Match geolocation against billing address to catch mismatches.
Build your own blocklists
Block specific emails, domains, IPs, or card fingerprints you've seen before. Build once, apply across all your apps.
Built for developers
REST API with copy-paste code samples. 5 lines of code and you're live in minutes, not sprint cycles.
From API key to blocked fraud in three steps
No SDK to install, no webhook gymnastics. One REST call from any language.
Sign Up
Create your account and get your API key in seconds. Start on the free plan, no credit card required.
Integrate
Add one API call to your Stripe webhook or signup form. Copy the code from our docs. 5 lines to start catching fraud.
Protect
Each request returns a risk score and a plain-English recommendation: allow, challenge, or block.
Teams using Fidro catch fraudulent payments before they become chargebacks, keep disposable emails out of their user base, and stop free tier abuse at the source.
The numbers behind it
Three figures worth knowing before you decide this is not a problem you have.
$190
Per chargeback
Lost product, fees, penalties, and operational costs per dispute. Just 10 chargebacks/month = $1,900 lost.
1 in 8
Signups are disposable
12% of form signups use throwaway emails. That's wasted infrastructure, skewed metrics, and inflated user counts.
1.5%
Visa VAMP threshold
Cross Visa's 2026 VAMP threshold and every dispute costs $8 in fees. Stripe and other processors flag accounts well before that.
Fidro's free plan starts catching these problems for $0, today. No credit card, no sales call, no procurement cycle.
Start free, scale as you grow
The free plan covers testing and small apps. Paid plans start at $29/month, less than the cost of a single chargeback.
Free
- 200 validations/month
- Email, IP & geolocation checks
- Velocity and anomaly detection
- GitHub Issues support
Starter
That's $0.97/day
- 5,000 validations/month
- Custom blocklists
- Webhook callbacks
- 90 day event memory
- Email support
Pro
That's $6.63/day
- 50,000 validations/month
- Stripe chargeback prevention
- Risk trend dashboard
- 365 day event memory
- Priority email support
Enterprise
- Custom validations
- Dedicated account manager
- Custom risk weights
- SLA guarantee
All plans include full email, IP, and geolocation checks. Upgrade or downgrade anytime. No contracts, no lock-in.
Fidro never stores the emails or IPs you validate. Data is processed in real-time and discarded.
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 free