Stop fraud before it costs you money
Fraudsters rent real home internet connections to hide where they are, and run browsers built to fake who they are. Kaidn reads the handshake underneath, the part they have to send before your page even loads.
No credit card. One API call. No sales team to get past.
This reads how your browser renders graphics, audio and text to build a device fingerprint — exactly what Kaidn does for customers. We don’t run it on you without asking.
What it reads →Built for the operators big fraud vendors ignore. One API for rewards, affiliates, crypto, SaaS, games or fintech. No enterprise contracts, no sales calls.
Both sides can be bought
- Clean home IP addresses cost pennies. Fraudsters buy them by the thousand, so checking the address stopped working years ago.
- The browser can be faked just as cheaply. A whole industry sells tools that give every fake account a convincing, different-looking device.
- So you turn away real customers while the professionals walk straight through.
The layer underneath
- We read the handshake, not the claim. How a connection is opened is set by the software, not by anything the page can edit.
- Then we check it against the whole network. Caught somewhere else this morning means known here, even on a new address and a new device.
- You get allow, review or block with the evidence in a sentence, not a score you have to take on faith.
Never a number you can’t explain.
Every answer tells you what we found, how much it counted, and why, in a sentence your support team could send to the customer. No mystery score.
The handshake gives it away
A bot can change everything its browser claims to be. It cannot easily change how it opens the connection in the first place, and we read that before your page even loads.
"t13d3112h2_8daaf61527df_845e22731872"One attack teaches the network
When one site on the network catches a fraudster, everyone else already knows them. Nothing readable is shared, so nobody, us included, can see another operator's customer list.
Where they connect from
VPNs, proxies, and the rented home connections fraud rings hide behind.
The same device, again
Recognise a returning browser after they clear cookies and change their details.
Too much, too fast
Ten signups from one place in a minute are not ten customers.
One inbox, many accounts
Throwaway addresses, and the tricks that turn one mailbox into fifty.
Run a check without an account
Rate limited, no key required. Results appear inline.
Fraud caught at every step
Block the farm
Bulk account creation, fake inboxes and residential proxy farms.
Catch the takeover
Account takeover, credential stuffing and session hijacking.
Stop card testing
Promo abuse and chargeback-prone proxy orders.
Guard the money
Device change or a suspicious geo shift before funds leave.
Anything else in your stack
Referral links, API keys, support requests. Name the event, set the rules, POST it.
How to stop it, by fraud type
How each attack actually runs, the defences that look sensible and fail anyway, and the signals that catch it.
All fraud typesHonest comparisons, including where we lose
What each tool is genuinely built for, and when you should buy theirs instead of ours.
All comparisonsNow the actual names
Everything above is deliberately in plain words. Here is what those things are actually called, in case you are comparing us to someone else and need to match the terms up. Anything still unclear is defined in the glossary.
JA4 TLS fingerprinting
Every piece of software opens an encrypted connection in a slightly different way, and that pattern is set by the software itself rather than by anything a page can edit. We capture it at our edge, so it survives a changed user agent, incognito, and a cleared fingerprint.
IP and ASN intelligence
An ASN identifies the network an address belongs to, which is how we flag an entire proxy seller rather than chasing single addresses. It is also what separates two strangers who happen to share a device fingerprint.
Velocity
Counting how often something happens in a short window. One signup tells you almost nothing; the same signup twelve times in a minute tells you a great deal. Windows and thresholds are yours to set.
Device identity, in three rungs
A browser fingerprint is not a person: on our own traffic one iOS Safari fingerprint covers 2.30 different people. So we resolve it into an identity, tell you which of three methods produced it, and return the measured odds that it still covers more than one person.
And the part we are honest about
None of this catches everything, and we publish where it fails rather than waiting for you to find out. A browser built to spoof the operating system it is already running on defeats our engine and the market leader’s alike. We measured it, wrote it up with the numbers, and shipped the post. Read the measurement →
Integrate in minutes
One POST, one answer
A REST call or the npm package, whichever you prefer. Send the fields you already collect; anything you do not have is optional. No sales call, no onboarding project, no contract to sign before you can test it on real traffic.
See why, and change your mind
The dashboard shows every decision with the signals that fired and what each one counted for. Disagree with an outcome and you can move that signal’s weight yourself, or the threshold, without asking us.
Use the @kaidn/sdk npm package, a plain REST call, or the browser tag. Score one event or a million through the same endpoint. Every field except event is optional.
// npm install @kaidn/sdk import { Kaidn } from "@kaidn/sdk"; const kaidn = new Kaidn({ apiKey: process.env.KAIDN_API_KEY }); const { verdict, reasons, reason_text } = await kaidn.score({ event: "cashout", user_id: "u_8231", ip: req.ip, email: user.email, device_id: fingerprint, // from @kaidn/fp in the browser event_country: offer.country, // optional geo expectation }); if (verdict === "block") return deny(reason_text); if (verdict === "review") await queueForReview(user, reasons); // the SDK covers every endpoint: await kaidn.check.ip("3.5.140.1"); await kaidn.batch.score(rows); // bulk, up to 1000 rows await kaidn.label({ label: "chargeback", event_id });
Investigate fraud by asking
Connect Claude, Cursor or any MCP client to your tenant. The agent gets the evidence behind every verdict, not a bare score. Big vendors gate this to invited enterprise accounts.
claude mcp add kaidn \ --env KAIDN_API_KEY=your_key \ -- npx -y @kaidn/mcp
Read-only by default. The two tools that change anything need an explicit --allow-writes, and a per-session quota ceiling means an agent stuck in a loop cannot burn your month.
On the page, like adults
Upgrade when the fraud you prevent pays for itself.
10,000 events / mo
- All engine checks + verdicts
- Email, IP & phone lookups
- Dashboard & free checker
- Allow / blocklists
50,000 events / mo
- AI reasons & insights
- Full scoring API access
- Custom rules (weights & thresholds)
- 14-day event retention
250,000 events / mo
- AI reasons & insights
- Custom rules (weights & thresholds)
- Allow / blocklists
- 30-day event retention
1,000,000 events / mo
- Everything in Starter
- Cross-network fraud graph
- 90-day event retention
- Higher rate limits
Custom volume
- Everything in Growth
- Custom event volume
- Custom retention
- Integration support
| COMPARE PLANS | FREE | BASIC | STARTER | GROWTH | ENTERPRISE |
|---|---|---|---|---|---|
| Events / month | 10,000 | 50,000 | 250,000 | 1,000,000 | Custom |
| AI-written reasons | — | ✓ | ✓ | ✓ | ✓ |
| All engine checks + verdicts | ✓ | ✓ | ✓ | ✓ | ✓ |
| Email · IP · phone lookups | ✓ | ✓ | ✓ | ✓ | ✓ |
| Allow / blocklists | ✓ | ✓ | ✓ | ✓ | ✓ |
| Custom rules (weights & thresholds) | — | ✓ | ✓ | ✓ | ✓ |
| Cross-network fraud graph | — | — | — | ✓ | ✓ |
| Event retention | 30 days | 60 days | 90 days | 180 days | Custom |
| Support | Community support | Email support | Email support | Priority support | Dedicated support + SLA |
Pricing questions, answered here
Is there really a free tier?
Yes: 10,000 events a month, forever, no card. It includes all engine checks and verdicts so you can evaluate Kaidn on your own traffic. AI-written reasons unlock on the paid plans.
How am I billed, and what about tax?
Paid plans are billed in advance, monthly or annually, and renew until you cancel. Payments run through Paddle, our Merchant of Record, which adds any applicable VAT or sales tax at checkout and sends your receipt. We never see your full card details.
What counts as an event?
One call to POST /v1/score is one event. The free-tool checkers and dashboard views do not count against your allowance.
What happens if I go over the limit?
We will let you know before it bites. Depending on your plan we may throttle, queue overage for billing at the published rate, or ask you to upgrade. We will not silently stop scoring your traffic.
Can I cancel or get a refund?
Cancel any time from your dashboard and you keep access to the end of the period you have paid for. Your first paid subscription is covered by a 14-day money-back window.
Do you offer annual or custom pricing?
Annual billing is available on every paid plan and saves two months. Enterprise is fully custom: email support@kaidn.io and we will size it with you.
Ready to stop paying fraudsters?
Start free with 10,000 events every month. No credit card. Your first integration takes less than five minutes.