Castle
Castle prevents account abuse with cybersecurity APIs and SDKs
Category
Recommended for
- Solo / Indie
- Idea-Stage
- Pre-Seed
- Seed
- Series A
- Scaleup
SSIE
Stage Fit Recommendations
Following data shows why Castle is recommended for listed teams. The Fit Score represents the percentage fit of Castle to each company stages, as calculated by the SSIE.
Stage
Fit Score
Fit Reasons
Solo / Indie
$0–$2,000 MRR
77- EU-US Data Privacy Framework - baseline compliance certification
- Free plan available (Free), no purchase required to start
- Self-serve signup from $5/mo, no sales call required
Idea-Stage
$0
93- Expose coordinated abuse with device, email, IP and behavioral intelligence
- Assess IP reputation and risk including proxies, VPNs, Tor and datacenter traffic
Pre-Seed
$0–$10k MRR
93- Detect bots, scripts and coordinated attacks with 99.5% accurate fingerprinting
- Spot account takeover attempts and abusive behavior using self-learning AI
Seed
$10k–$100k MRR
93- Create custom signals, aggregations and rate limiters for unique abuse patterns
- Monitor, analyze and alert on up to 18 months of historical user and device data
Series A
$100k–$500k MRR
93- Single sign-on with SAML and directory provisioning
- Multi-factor authentication
- Query and visualize abuse patterns and turn them into rules
- Test risk logic on historical data before disrupting legitimate users
Scaleup
$500k–$2M+ MRR
77- Uptime SLA on the Enterprise plan
- Dedicated support / CSM on the Enterprise plan
- Provide full user and company history down to page views and custom actions
- Manage dynamic trust, block and review lists of users, devices or attributes

Castle is a security and compliance solution that offers a suite of APIs and SDKs to monitor user behavior, block malicious bots, and prevent in-app fraud. By integrating Castle into your application, you can leverage its freemium model to stop account abuse and ensure enterprise-grade cybersecurity without added friction. The platform seamlessly connects with Cloudflare or custom edge stacks, providing flexible deployment options. With various plans available, including a free plan and custom enterprise solutions, Castle caters to diverse business needs, prioritizing dedicated support and higher rate limits for its pro and enterprise users. By utilizing Castle's cybersecurity capabilities, businesses can effectively mitigate risks associated with account takeover and maintain a secure user environment.
Pricing
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