Skip to content

MCP Context Forge Plugin Framework Specification

Version: 1.0 Status: Draft Last Updated: January 2025 Authors: Plugin Framework Team

Table of Contents

  1. Introduction
  2. Architecture Overview
  3. Core Components
  4. Plugin Types and Models
  5. Hook Function Architecture
  6. Hook System
  7. Gateway Admin Hooks
  8. MCP Security Hooks
  9. External Plugin Integration
  10. Security and Protection
  11. Error Handling
  12. Performance Requirements
  13. Development Guidelines
  14. Testing Framework
  15. Conclusion

1. Introduction

1.1 Purpose

The MCP Context Forge Plugin Framework provides a comprehensive, production-ready system for extending MCP Gateway functionality through pluggable middleware components. These plugins interpose calls to MCP and agentic components to apply security, AI, business logic, and monitoring capabilities to existing flows. This specification defines the architecture, interfaces, and protocols for developing, deploying, and managing plugins within the MCP ecosystem.

1.2 Scope

This specification covers: - Plugin architecture and component design - Plugin types and deployment patterns - Hook system and execution model - Configuration and context management - Security and performance requirements - External plugin integration via MCP protocol - Development and testing guidelines - Operational considerations

1.3 Design Principles

  1. Platform Agnostic: Framework can be embedded in any Python application. The framework can also be ported to other languages.
  2. Protocol Neutral: Supports multiple transport mechanisms (HTTP, WebSocket, STDIO, SSE, Custom)
  3. MCP Native: Remote plugins are fully compliant MCP servers
  4. Security First: Comprehensive protection, validation, and isolation
  5. Production Ready: Built for high-throughput, low-latency environments
  6. Developer Friendly: Simple APIs with comprehensive tooling

1.4 Terminology

  • Plugin: A middleware component that processes MCP requests/responses
  • Hook: A specific point in the MCP lifecycle where plugins execute
  • Native Plugin: Plugin running in-process with the gateway
  • External Plugin: Plugin running as a remote MCP server
  • Plugin Manager: Core service managing plugin lifecycle and execution
  • Plugin Context: Request-scoped state shared between plugins
  • Plugin Configuration: YAML-based plugin setup and parameters