How to Build Your Own Castle
Replace Castle with a custom build. Stop bots and account abuse in minutes
Build Difficulty: 4/5
A few focused days to build a solid replacement
Estimated Timeline
Based on 41 features at Few Days difficulty, expect about 3-5 days with AI-assisted development.
Recommended Tech Stack
Full-stack React framework with API routes and server components
PostgreSQL database, auth, and real-time subscriptions
Utility-first styling for rapid UI development
Key Features to Replicate
Top features across 8 categories. See all 41 features
Detection(21 features)
Identify both bot and human account takeover attacks using scores and heuristics
Use out-of-the-box signals or create custom aggregations and rate limiters
Detect generated emails, abuse IPs, credential stuffing, web crawlers, and automated patterns
Detect bots, scripts, and coordinated attacks while identifying automated behavior and tampering
99.5% accurate fingerprinting that uncovers headless browsers, tampering, and carrier data
+16 more in this category
Analytics(4 features)
Spot network of bad user activity via shared devices, emails, IPs, payment methods, or addresses
Uncover bad user activity by querying and visualizing large amounts of data and turn into rules with a few clicks
Get a complete history of each user and company down to individual page views and custom actions
Monitor, analyze, and alert on up to 18 months of historical data enriched with user and device intelligence
Integration(3 features)
Connect Castle to Cloudflare with no code for edge deployment
Add SDK to track sessions, devices, and behavior enriched with business context for in-app fraud detection
Receive real-time webhooks for fraud events and policy decisions
Scoring(3 features)
Risk score indicating likelihood of abusive activity (0-100)
Account Takeover risk score indicating likelihood of account compromise (0-100)
Risk score indicating likelihood of bot activity (0-100)
Customization(2 features)
Define and track custom metrics for your fraud detection
Create custom signals based on your application's specific needs
Policy & Rules(2 features)
Create and manage security policies for different user actions and risk levels
Real-time allow, challenge, or deny actions with seamless rule management without code changes
AI & ML(1 features)
Self-learning AI that spots account takeover attempts and abusive behavior
API(1 features)
Query Castle risk data in real-time via API
Cost Calculator
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Total Cost Comparison
DIY hosting estimate based on Vercel + Supabase free/pro tiers (~$20/mo). Build time estimated from 41 features at easy complexity.