Concepts
Hooks
Middleware pattern for MCP request processing
Overview
Hooks provide a middleware layer for intercepting and processing MCP requests and responses. They enable you to add custom logic, security rules, or transformations without modifying the underlying MCP servers.How Hooks Work
- Inspect the request/response data
- Modify parameters or results
- Block requests based on custom rules
- Enrich data with additional context
Common Hook Patterns
- Security Filtering: Validate requests against security policies
- Rate Limiting: Control request frequency and volume
- Data Transformation: Modify request/response formats
- Audit Logging: Record all tool interactions
- Content Filtering: Remove or redact sensitive information
In Civic Labs
Hooks power several of our security tools:- The Pass-through Proxy provides the core hook infrastructure
- The Guardrail Proxy implements security rules as hooks
- Bodyguard can be deployed as a hook for threat detection
Learn More
- Pass-through Proxy - The middleware system that enables hooks
- Guardrail Proxy - Security implementation using hooks