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Fraud Detection for SaaS

Stop Free Trial Abuse, Fake Signups & Competitor Scraping

SaaS platforms lose revenue daily to proxy-masked trial abuse, multi-accounting, and automated scraping. Sentinel detects the tools attackers use — invisibly, in under 40ms.

< 40msResponse time globally
Free1,000 req/hr, no credit card
0CAPTCHAs required
400+Device signals per session

What SaaS platforms face in 2026

Trial abuse via proxy rotation

Competitors and freeloaders spin up hundreds of trial accounts using residential proxies that bypass IP-based limits. Each one burns your infrastructure and distorts your conversion metrics.

Multi-accounting with antidetect browsers

Users create multiple accounts using Kameleo, GoLogin, or AdsPower to game referral bonuses, avoid bans, or test your product for free indefinitely.

Feature scraping by competitors

Bots using clean residential IPs systematically map your UI, extract pricing, and benchmark your product — bypassing rate limits and bot detection.

Fake signups inflating metrics

Bot-generated signups make your funnel metrics meaningless, waste sales team time on fake leads, and inflate your MAU numbers.

What Sentinel does for you

  • Detect proxy-masked trial signups before they consume resources
  • Link multiple accounts to the same device even across different IPs and browsers
  • Identify antidetect browser usage during signup and login
  • Block automated scraping bots without adding CAPTCHAs
  • Score every session in under 40ms — zero impact on UX
€96K

recovered by a B2B SaaS in six months by blocking proxy-based trial abuse

[ Read Full Case Study ]

Where the check goes

Two call sites cover most SaaS abuse: signup (before you provision a workspace, send a verification email, or count the trial in your metrics) and login (where credential stuffing and account sharing show up). The client snippet rides along in your existing form; the server asks Sentinel for a verdict before your business logic runs.

// Gate trial signups before provisioning anything
const res = await fetch('https://sntlhq.com/v1/evaluate', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer ' + process.env.SENTINEL_KEY,
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({ token: req.body.sentinel_token })
});
const risk = await res.json();
if (risk.decision === 'block') return res.status(403).json({ error: 'Signup rejected' });
if (risk.decision === 'review') flagForReview(risk.reasons);

The signals that matter for SaaS

Devices, not IPs. Trial abusers rotate residential proxies faster than any blocklist updates, but the hardware underneath stays the same. Sentinel keys its "times seen" counter to a cross-browser hardware ID, so account #2 through #50 from the same laptop link together even when every one arrives from a different IP and a fresh browser profile. That device graph is what actually ends multi-accounting — not signup friction.

Network context at signup, not just at login. A datacenter IP or commercial VPN on a paying user's login is often just privacy hygiene. The same signal on a brand-new trial signup correlates strongly with abuse, because legitimate evaluations overwhelmingly start from home and office networks. Sentinel returns the raw signals so you can apply exactly that kind of asymmetric policy.

Antidetect artifacts before compute burns. Kameleo, GoLogin, and AdsPower spoof canvas, WebGL, and fonts — but the spoofing itself leaves measurable artifacts. Catching them at signup means the abuser never gets a workspace, never consumes an LLM quota, and never pollutes your activation metrics.

Automation on your public surface. Pricing scrapers and docs crawlers run headless Chrome with stealth patches. The device layer sees through the patches, and because the verdict is an API response rather than a challenge, you can block them without ever showing a CAPTCHA to a real prospect.

Common questions

How does Sentinel stop free-trial abuse?
Sentinel links trial signups by device fingerprint, behavioral pattern, and network signals — even when emails, payment methods, and IPs are different. Coordinated multi-accounting rings drop by an average of 93% after deployment.
Can Sentinel prevent credential-stuffing attacks?
Yes. Sentinel detects rotating residential-proxy traffic and automation signals that evade IP-based rate limiting. Login endpoints typically see a 95%+ reduction in credential-stuffing attempts within two weeks.
Does Sentinel work for B2B SaaS with low signup volume?
Yes. High-value B2B SaaS with fewer but larger deals benefits most — each blocked abuse incident saves potentially thousands in API usage, compute cost, or enterprise-lead pollution. The free tier handles most B2B volume.
Will it degrade signup conversion?
No. Sentinel is invisible to legitimate users — no CAPTCHAs, no latency above 40ms. False-positive rates measured across SaaS deployments sit below 0.3%, and legitimate signup conversion is unaffected.
How quickly can a SaaS team deploy Sentinel?
Most SaaS teams integrate in under an hour: drop the JS snippet on signup and login pages, then call the risk API from the server. Detailed guides exist for Node.js, Python, Go, Ruby, Rails, Django, and Next.js.

Start protecting your SaaS platform

Free tier. 1,000 API requests per hour. No credit card. Detects residential proxies, antidetect browsers, and AI bots.

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