Kaidn - 2026 Pricing, Features, Reviews & Alternatives

Fraud costs you money at the moment of the transaction, not at the end of the month. Kaidn scores the event while it is still open and tells you what to do about it.

One authenticated POST to /v1/score takes any user event, a signup, a login, a checkout, a payout or a withdrawal, and returns a verdict of allow, review or block, a 0 to 100 score, and the exact list of reasons behind it. Rules catch fraud, and AI explains every decision. No black boxes and no mystery scores, so support can tell a real customer why they were held and your fraud team can audit any verdict months later.

How it works

Network layer. The TLS handshake is fingerprinted at the edge with JA4 before your page loads, so the signal reflects the client that actually connected rather than what the browser claims. Every IP is resolved to its ASN and classified as residential, mobile, hosting or datacenter, then scored against a first-party reputation built from traffic Kaidn has already seen. Public proxy and abuse blocklists refresh hourly.

Device layer. An optional browser script produces a stable device identifier plus a set of integrity checks that run entirely client side, with no extra round trip on your critical path. It compares the main thread against a Web Worker, checks whether native canvas, WebGL and navigator functions have been overridden, re-renders canvas, WebGL and audio to catch per-read noise injection, and compares the operating system the user agent claims against the system fonts and platform headers that leak the real one.

Behaviour layer. Velocity across accounts, devices and IP addresses. Repeat device identities across signups. Timezone against IP country. Disposable and pattern-generated email addresses. Cross-operator intelligence, so a fraudster caught on one platform is known on yours, exchanged as hashed identifiers rather than user lists.

Explanations you can act on

Every verdict carries reason codes and a written explanation. The dashboard shows which signals fired on an event, the weight each one carried and the running total that produced the score, so you tune thresholds against your own traffic instead of trusting a default you cannot inspect.

Integration

A REST API over TLS, authenticated with an API key. Official SDKs on npm: @kaidn/sdk for Node and TypeScript, @kaidn/fp as a drop-in browser fingerprint script, @kaidn/nextjs for Next.js, and @kaidn/mcp, an MCP server that lets an AI assistant query your events and verdicts directly. Bulk CSV scoring is available for reviewing historical cohorts. There is no mandatory onboarding call and no implementation project. A working integration is a single request.

Security and data

Kaidn stores the signals needed to make and defend a decision, not your customers' personal data. Shared intelligence is exchanged as hashed identifiers, so you benefit from fraud caught elsewhere without exposing your users. Verdicts and their reasons are retained so any decision can be reviewed or disputed later.

Pricing

10,000 events a month are free, with no card. Paid plans start at $39 a month and pricing is published rather than quoted. The cross-operator fraud graph is included from the Growth plan. Free tools let you test Kaidn against your own traffic before you commit.