TanStack Start Best Practices

Comprehensive guidelines for implementing TanStack Start patterns in full-stack React applications. These rules cover server functions, middleware, SSR, authentication, and deployment.

When to Apply

• Creating server functions for data mutations
• Setting up middleware for auth/logging
• Configuring SSR and hydration
• Implementing authentication flows
• Handling errors across client/server boundary
• Organizing full-stack code
• Deploying to various platforms

Rule Categories by Priority

Priority	Category	Rules	Impact
CRITICAL	Server Functions	5 rules	Core data mutation patterns
CRITICAL	Security	4 rules	Prevents vulnerabilities
HIGH	Middleware	4 rules	Request/response handling
HIGH	Authentication	4 rules	Secure user sessions
MEDIUM	API Routes	1 rule	External endpoint patterns
MEDIUM	SSR	6 rules	Server rendering patterns
MEDIUM	Error Handling	3 rules	Graceful failure handling
MEDIUM	Environment	1 rule	Configuration management
LOW	File Organization	3 rules	Maintainable code structure
LOW	Deployment	2 rules	Production readiness

Quick Reference

Server Functions (Prefix: sf-)

• sf-create-server-fn — Use createServerFn for server-side logic
• sf-input-validation — Always validate server function inputs
• sf-method-selection — Choose appropriate HTTP method
• sf-error-handling — Handle errors in server functions
• sf-response-headers — Customize response headers when needed

Security (Prefix: sec-)

• sec-validate-inputs — Validate all user inputs with schemas
• sec-auth-middleware — Protect routes with auth middleware
• sec-sensitive-data — Keep secrets server-side only
• sec-csrf-protection — Implement CSRF protection for mutations

Middleware (Prefix: mw-)

• mw-request-middleware — Use request middleware for cross-cutting concerns
• `...