MCP Hub

MCP Hub is a local web UI for testing LLMs and MCP servers. Connect providers, inspect tool calls, and run multi-turn chats in one place.

MCP Hub chat interface

Architecture Overview

┌──────────────────────────────────────────────┐
│                  Browser UI                  │
│        (Next.js App Router + shadcn/ui)      │
└─────────────────────┬────────────────────────┘
                      │
┌─────────────────────▼────────────────────────┐
│           Next.js Server (local)             │
│                                              │
│  ┌──────────────────┐  ┌──────────────────┐  │
│  │    AI Routes     │  │    MCP Routes    │  │
│  │  Vercel AI SDK   │  │  @mcp/sdk client │  │
│  └────────┬─────────┘  └────────┬─────────┘  │
└───────────┼─────────────────────┼────────────┘
            │                     │
┌───────────▼────────┐  ┌─────────▼────────────┐
│   LLM Providers    │  │     MCP Servers      │
│   (10 providers)   │  │  stdio / SSE / HTTP  │
└────────────────────┘  └──────────────────────┘

MCP Hub consists of two components that work together:

MCP Hub Server: A Next.js standalone server that runs locally via npx. It acts as the bridge between the browser and external services, spawning MCP stdio processes, connecting to remote MCP servers over SSE or Streamable HTTP, and forwarding LLM requests to the configured provider.

MCP Hub Client: A React-based web UI served by the local server. It provides the interface for configuring providers, managing MCP connections, inspecting tool schemas, and running multi-turn chats with live tool call traces.

All traffic stays on localhost except direct calls to the LLM providers you configure.

Quick Start
Features
Stack
Security
Limitations
Links

Quick Start

npx @thiagorufino/mcp-hub

Starts on http://127.0.0.1:3000 by default and opens the browser automatically. If the port is already taken, the CLI picks the next free local port.

To update to the latest version:

npx @thiagorufino/mcp-hub@latest

# Custom port
npx @thiagorufino/mcp-hub --port 4010

# Bind explicitly to localhost without auto-opening the browser
npx @thiagorufino/mcp-hub --host localhost --port 3000 --no-open

# IPv6 loopback is also allowed
npx @thiagorufino/mcp-hub --host ::1

# Show all options
npx @thiagorufino/mcp-hub --help

Requires Node.js 20+

The public CLI refuses non-local host binding. Allowed hosts: 127.0.0.1, localhost, ::1.

Features

LLM Providers

Configure any of the 10 supported providers directly in the UI:

Provider	Supported
Anthropic	✅
AWS Bedrock	✅
DeepSeek	✅
Google Gemini	✅
Groq	✅
Microsoft Foundry	✅
Mistral AI	✅
Ollama	✅
OpenAI	✅
xAI	✅

MCP Servers

Connect to MCP servers over all three transports:

Transport	Description
stdio	Local process spawned by the app
SSE	Remote server-sent events endpoint
Streamable HTTP	Modern MCP transport

Inspect tools, schemas, and execute calls directly from the sidebar.

Automatic health revalidation: MCP status updates when a server goes offline or comes back
Per-server recovery logic: one failing MCP does not block others from being revalidated
Manual retest controls: force validation whenever you want from the sidebar

Chat

Streaming responses with live token display
Multi-turn conversation history
System Prompt support
Token usage tracking: input, output, and total tokens per message and accumulated per session
Tool activity trace: see every MCP tool call and result in real time
Chart rendering: ask for charts, get interactive visualizations inline
Audio input support
MCP-aware chat requests: fresh validated MCP snapshot before exposing tools to the model

Stack

Layer	Technology
Framework	Next.js 16 (App Router, standalone output)
AI	Vercel AI SDK 6, unified streaming across all providers
MCP	@modelcontextprotocol/sdk
UI	Tailwind CSS 4 + Radix UI + shadcn/ui
Icons	@lobehub/icons, official AI provider brand icons

Security

Runs locally on loopback interfaces only. Credentials are sent only to providers you configure and never stored in any remote backend.

LLM credentials and MCP auth headers/env stored only in browser sessionStorage
Closing the tab clears all sensitive config
Chat history and non-sensitive UI preferences may persist locally
MCP stdio servers are spawned as child processes, so only connect to servers you trust
CLI refuses non-local host binding by design

See SECURITY.md for the full security model.

Limitations

CLI app distributed via npm, not a library API
First launch downloads the standalone Next.js bundle, which may take a moment
Provider credentials are session-scoped, so you must re-enter them in new browser sessions
Remote multi-user deployment is out of scope

License

Apache License 2.0. See LICENSE.

@thiagorufino/mcp-hub

Quick Install