# McpMux - The Largest MCP Server Registry & Manager (Complete Technical Reference)

> McpMux is the largest MCP server registry and marketplace, plus a free, open-source desktop application and local MCP gateway for centralized Model Context Protocol (MCP) server management. Browse, install, and manage 100+ MCP servers for Cursor, Claude Desktop, Claude Code, VS Code (GitHub Copilot), ChatGPT, Windsurf, JetBrains, Cline, Zed, Gemini CLI, and Amazon Q Developer through a single localhost:45818 endpoint with encrypted credential storage.

## Overview

McpMux solves the fragmented MCP configuration problem. Today, every AI-powered application (Cursor, Claude Desktop, VS Code, ChatGPT, Windsurf, JetBrains) requires separate MCP configuration files with duplicated credentials stored in plain-text JSON. McpMux centralizes this into a single desktop app with:

1. A curated registry of 100+ MCP servers
2. One-click installation and configuration
3. DPAPI-based credential encryption (AES-256-GCM)
4. Multi-workspace isolation via Spaces
5. Granular permission control via FeatureSets
6. A local HTTP gateway that routes MCP requests to the correct servers

## Core Concepts

### Spaces
Isolated environments with separate credentials and server configurations. Examples:
- **Work Space**: Company GitHub, Jira, Confluence access
- **Personal Space**: Personal GitHub, hobby project tools
- **Client Space**: Client-specific tools and access credentials

### MCP Servers
MCP servers provide tools, resources, and prompts to AI clients. McpMux manages their lifecycle:
- Browse and install from the curated server registry
- Configure authentication (API keys, OAuth 2.1 + PKCE)
- Monitor server health and connection status
- Automatic startup/shutdown management

### FeatureSets
Named bundles of MCP primitives (tools, prompts, resources) for granular access control:
- **As Domain Profiles**: "Android Development" (GitHub + Firebase + Play Store), "Web Development" (GitHub + Vercel + NPM)
- **As Permissions**: "Read Only" (search, view, list), "Write Access" (create, update), "No Delete" (safety net)
- **As Role Bundles**: "Senior Developer" (full access), "Junior Developer" (safe mode), "Product Manager" (docs + visibility)

### Clients
AI applications connected to McpMux, each with their own access key and assigned FeatureSets:
- Cursor, Claude Desktop, Claude Code, VS Code (GitHub Copilot), ChatGPT, Windsurf, JetBrains, Cline, Zed, Gemini CLI, or any MCP-compatible host
- Per-client access keys for authentication
- FeatureSet assignments control what each client can access

## Architecture

### Data Flow
```
AI Clients -> McpMux Gateway (localhost:45818/mcp) -> MCP Servers (stdio/HTTP)
                     |
              Authenticates (per-client access keys)
              Routes (per-space server configuration)
              Filters (FeatureSet permission evaluation)
              OAuth token refresh (automatic)
              Credentials (DPAPI-encrypted keys + encrypted SQLite)
```

### Technology Stack
- **Desktop App**: Tauri 2 (Rust backend + React 19 frontend)
- **HTTP Gateway**: Axum (Rust) bound to localhost:45818
- **Storage**: SQLite with AES-256-GCM field-level encryption via ring crate
- **Credential Security**: Platform-native DPAPI encryption, zeroize for secure memory clearing
- **MCP Client**: rmcp SDK for MCP protocol communication
- **Frontend**: React 19, Zustand state management, Tailwind CSS, Monaco Editor

### Rust Crate Architecture
- **mcpmux-core**: Domain layer (entities, repository traits, services, EventBus)
- **mcpmux-gateway**: Axum HTTP gateway (routing, OAuth, FeatureSet filtering, connection pooling)
- **mcpmux-storage**: SQLite persistence with encryption and DPAPI key management
- **mcpmux-mcp**: MCP protocol client management using rmcp SDK

### MCP Protocol Support (Specification 2025-11-25)
| Feature | Support |
|---------|---------|
| stdio transport | Full |
| Streamable HTTP | Full |
| OAuth 2.1 | Full |
| Tools, Prompts, Resources | Full |
| Notifications (list_changed) | Full |
| Elicitation (user input) | Full |
| Sampling (LLM requests) | Pass-through |
| Roots (directory boundaries) | Per Space |

## Security Features

1. **Encrypted Storage**: Secrets encrypted with platform-native DPAPI and stored securely by McpMux
2. **AES-256-GCM**: Field-level database encryption for all sensitive data
3. **OAuth 2.1 + PKCE**: Standard auth flow with automatic token refresh
4. **Local-only gateway**: Binds to 127.0.0.1 only, nothing exposed to the network
5. **Per-client access keys**: Granular permissions for each connected AI client
6. **Sanitized logs**: Tokens and secrets never appear in log files
7. **Memory zeroization**: Secrets wiped from memory after use via zeroize crate

## MCP Server Registry

The McpMux server registry at mcpmux.com is the largest curated catalog of MCP servers, organized by category. Each server can be installed with one click and works with all MCP-compatible AI clients.

### Popular MCP Servers

- **GitHub MCP Server** (Official, HTTP) — Repository management, issues, pull requests, code search via GitHub API. URL: https://mcpmux.com/servers/com.github-mcp-http-pat/
- **Slack MCP Server** (Official, stdio) — Send messages, manage channels, search conversations. URL: https://mcpmux.com/servers/com.slack-mcp-npx/
- **PostgreSQL MCP Server** (Community, stdio) — Query databases, manage schemas, inspect tables, run migrations. URL: https://mcpmux.com/servers/crystaldba.postgres-mcp-uvx/
- **Cloudflare MCP Server** (Official, HTTP) — Search and browse Cloudflare documentation and APIs. URL: https://mcpmux.com/servers/com.cloudflare-docs/
- **Brave Search MCP Server** (Community, stdio) — Web search with privacy-focused results. URL: https://mcpmux.com/servers/community.brave-search-npx/
- **Notion MCP Server** (Official, HTTP) — Create pages, query databases, manage workspaces. URL: https://mcpmux.com/servers/com.notion-mcp-http/
- **Linear MCP Server** (Official, HTTP) — Issue tracking, project management, sprint workflows. URL: https://mcpmux.com/servers/com.linear-mcp-http/
- **Sentry MCP Server** (Official, HTTP) — Error tracking, performance monitoring. URL: https://mcpmux.com/servers/com.sentry-mcp-http/
- **Redis MCP Server** (Official, stdio) — Key-value operations, pub/sub, cache management. URL: https://mcpmux.com/servers/com.redis-mcp-docker/
- **Puppeteer MCP Server** (Community, stdio) — Browser automation, screenshots, web scraping. URL: https://mcpmux.com/servers/community.puppeteer/
- **Filesystem MCP Server** (Community, stdio) — Secure file operations with access controls. URL: https://mcpmux.com/servers/community.filesystem/
- **SQLite MCP Server** (Community, stdio) — Local database queries with schema inspection. URL: https://mcpmux.com/servers/community.sqlite/

### MCP Server Categories

- **Developer Tools**: GitHub, Docker, Puppeteer, Sentry, and more — https://mcpmux.com/servers/category/developer-tools/
- **Database**: PostgreSQL, SQLite, Redis, MongoDB, and more — https://mcpmux.com/servers/category/database/
- **Search & Web**: Brave Search, web crawlers, and more — https://mcpmux.com/servers/category/search/
- **Productivity**: Slack, Notion, Linear, and more — https://mcpmux.com/servers/category/productivity/
- **Cloud Services**: AWS, Cloudflare, Stripe, Vercel, and more — https://mcpmux.com/servers/category/cloud/
- **File System**: Filesystem, Google Drive, and more — https://mcpmux.com/servers/category/file-system/

### Server Listing Details

Each server listing includes transport type (stdio/HTTP), authentication requirements (none, API key, OAuth), capabilities (tools/resources/prompts), trust level (Official/Verified/Community), and one-click installation via mcpmux:// deep links. Browse all servers at: https://mcpmux.com/

## Installation

McpMux is available for:
- **macOS**: Apple Silicon (.dmg) and Intel (.dmg)
- **Windows**: MSI installer and portable .exe
- **Linux**: AppImage, .deb (Ubuntu/Debian), .rpm (Fedora/RHEL)

Download from: https://mcpmux.com/download/
Source code: https://github.com/mcpmux/mcp-mux

## Links

- Website: https://mcpmux.com
- GitHub Organization: https://github.com/mcpmux
- Server Registry Source: https://github.com/mcpmux/mcp-servers
- API: https://api.mcpmux.com