All Use Cases

Block Account Takeover Attacks

Add IP intelligence and memory to your auth flow. Send each login with the user_id and Fidro checks the IP for VPN/proxy usage, compares the login against where that user has been before, and flags new countries and impossible travel so you can challenge account takeovers in real time.

What is Fidro?

Fidro is a fraud detection API that combines email validation, IP intelligence, geolocation analysis, and Stripe chargeback prevention in a single API call. Built for developers at startups and growing companies, Fidro returns a risk score with a clear recommendation, allow, challenge or block, so you can stop fraud without building your own scoring logic. Fidro offers a free plan with 1,000 validations per month, no credit card required.

The Problem

Account takeover attacks cost businesses billions annually. Stolen credentials, session hijacking, and social engineering let attackers access real user accounts. Password-only auth isn't enough.

The Fidro Solution

Fidro adds an intelligence layer to your auth flow. Analyze login IPs for VPN/proxy usage, remember each user's countries and IPs, and flag new_country_for_user and impossible_travel when a login does not fit.

Key Features

Login IP Analysis

Check every login attempt against known VPN, proxy, and Tor exit node databases.

Geographic Anomaly Detection

Send event: login with the user_id and Fidro flags a new country for that user, or two countries within an hour as impossible_travel.

Shared IP Detection

ip_many_users fires when five or more different user_ids log in from one IP in a day, the shape of a credential-stuffing run.

Real-time
Analysis speed
Global
IP database
Zero
False positives on known threats

Learn more about Fidro

Explore our features, see how we compare, or try Fidro for free.

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Frequently Asked Questions

How do I prevent account takeover attacks?
Call Fidro's /validate endpoint on every login with the IP, event: login and your user_id. Fidro analyzes the IP for VPN/proxy usage, compares the login against the countries and IPs it has seen for that user, and returns a challenge recommendation when the login does not fit, so you can step up to 2FA for that request only.
What are signs of an account takeover?
Common indicators include logins from new geographic locations, use of VPNs or proxies, rapid login attempts from different IPs, and email address changes to disposable domains. Fidro detects all of these signals.
Can Fidro detect VPN usage on login?
Yes, Fidro's IP intelligence identifies VPN providers, proxy networks, Tor exit nodes, and data center IPs. You can use this data to require additional verification for logins from masked IP addresses.
Does Fidro replace two-factor authentication?
No, Fidro complements 2FA by adding an intelligence layer. While 2FA verifies identity, Fidro assesses risk signals like IP reputation and geolocation to detect suspicious login attempts that warrant additional scrutiny.

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