Castle
Castle protects user accounts and transactions from takeover, fraudulent signups and abusive usage with a developer-first API. It offers risk scoring, device fingerprinting, webhooks and policies, and is popular with SaaS companies like Sho
Our Verdict
The right pick for SaaS teams that want ATO and signup protection via API without an enterprise contract.
Pros
- Developer-first API with clear docs and webhooks
- Policies let you codify risk rules without retraining
- Fast integration for SaaS login and signup flows
- Reasonable pricing for mid-market SaaS
Cons
- Weaker on payment fraud vs PSP-native tools
- Smaller data network than LexisNexis or Ekata
- Requires you to tune rules and thresholds yourself
- Limited out-of-box bot mitigation vs DataDome
When to Use Castle
Good fit if you need
- Risk scoring for new user signup abuse prevention
- Account takeover detection via device fingerprint changes
- SaaS platform abuse policy enforcement via webhooks
- Fraud signal enrichment for Shopify checkout flows
- Adaptive MFA trigger based on real-time risk score
Pricing
Price wrong?Castle Pricing
- Pricing Model
- freemium
- Free Tier
- Yes
- Entry Price
- —
- Enterprise Available
- No
- Transparency Score
- —
Beta — estimates may differ from actual pricing
Estimated Monthly Cost
$25
Estimated Annual Cost
$300
Estimates are approximate and may not reflect current pricing. Always check the official pricing page.
Lock-in Assessment
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