MCP Fusion

What it does

MCP Fusion is a professional TypeScript framework designed for building production-ready Model Context Protocol (MCP) servers. It shifts security and governance from the system prompt to the architectural level, ensuring that raw data is filtered through typed egress firewalls before reaching the LLM.

Tools

As a framework, MCP Fusion provides tools for developers to build their own servers, including:

• Presenter API: Enforces Zod-based schema validation and PII redaction for all server responses.
• FSM State Gating: Dynamically removes tools from the agent's namespace based on the current workflow state (using XState v5).
• Governance Stack: Provides behavioral digests, lockfiles, and crypto-attestations to ensure server behavior is auditable and version-controlled.
• Sandbox Engine: Executes LLM-provided JavaScript in sealed V8 isolates for safe code execution.

Installation

To start a new project with MCP Fusion, run:

npx @mcpfusion/core create my-server

For Claude Desktop, add the resulting server to your claude_desktop_config.json using the stdio transport.

Supported hosts

Confirmed support for Cursor, Claude Code, GitHub Copilot, and Windsurf through its AI-ready SKILL.md and llms.txt integration.