Security

UI Component Isolation

Fractal renders every component inside an isolated iframe. This creates a secure sandbox that:

• Prevents components from accessing data outside their iframe
• Blocks the main application from seeing inside component iframes
• Ensures complete isolation between components and host applications

Since Fractal effectively transforms any chat application into a browser capable of running arbitrary code, security isolation is critical.

Data Flow Control

Communication between components and the host application uses a controlled messaging protocol with strict limitations:

• Current release: Only lifecycle management messages are permitted
• Upcoming release: Selective data sharing controls will allow marking specific data as non-sensitive, enabling richer agent interactions while maintaining security

MCP Server Protection

Fractal-powered MCP servers include built-in authentication that restricts access to:

• localhost connections
• Fractal MCP proxy requests only

This default configuration protects your server from unauthorized access while maintaining seamless integration with the Fractal ecosystem.