Mcp Explorer

MCP Explorer

A web-based GUI for exploring and interacting with Model Context Protocol (MCP) servers. Connect to any MCP server, browse its capabilities, and execute tools, read resources, and test prompts — all from your browser.

Features

• Connect to any MCP server — supports both Streamable HTTP and SSE transports (auto-detects)
• Authentication — Bearer token, custom header, or no auth
• Browse Tools — list all tools, view schemas, fill in parameters, and execute them
• Browse Resources — list and read resources exposed by the server
• Browse Prompts — list prompts, fill in arguments, and retrieve rendered output
• Parameter Store — save and reuse frequently used parameter values across sessions
• URL History — remembers previously connected server URLs
• Clean UI — minimal, responsive interface with tabbed navigation

Quick Start

Prerequisites

• Python 3.13+
• uv (recommended) or pip

Install & Run

# Clone the repo
git clone https://github.com/ventz/mcp-explorer.git
cd mcp-explorer

# Install dependencies
uv sync

# Run the server
uv run python app.py

Open http://localhost:8000 in your browser.

Using pip

pip install fastapi 'uvicorn[standard]' jinja2 mcp
python app.py

Usage

1. Enter an MCP server URL (e.g., http://localhost:3000/mcp)
2. Optionally configure authentication (Bearer token or custom header)
3. Click Connect
4. Use the tabs to explore Tools, Resources, and Prompts
5. Select an item to view its details, fill in parameters, and execute

Project Structure

mcp-explorer/
├── app.py              # FastAPI backend — MCP client + API routes
├── pyproject.toml       # Python project metadata & dependencies
├── templates/
│   └── index.html       # Main HTML template
└── static/
    ├── app.js           # Frontend application logic
    └── style.css        # Styles

API Endpoints

| Method | Path | Description | |--------|---------------------|------------------------------| | GET | / | Web UI | | GET | /health | Health check | | POST | /api/connect | Connect to an MCP server | | POST | /api/disconnect | Disconnect | | GET | /api/status | Connection status | | GET | /api/tools | List available tools | | POST | /api/tools/call | Execute a tool | | GET | /api/resources | List available resources | | POST | /api/resources/read | Read a resource | | GET | /api/prompts | List available prompts | | POST | /api/prompts/get | Get a rendered prompt |

Security & Deployment Notes

This is a local developer tool. It connects to whatever URL you give it and has no authentication of its own, so keep the following in mind:

• Binds to 127.0.0.1 by default. Only processes on your machine can reach

it. Override with MCP_EXPLORER_HOST only if you understand that exposing the proxy lets anyone who can reach it connect outward through your machine.

• SSRF guard. Requests to link-local (including the cloud metadata address

169.254.169.254), multicast, and reserved addresses are always refused. Loopback and private (RFC1918) addresses are allowed by default so you can reach local MCP servers; set MCP_EXPLORER_BLOCK_PRIVATE=1 to refuse those too (useful if you ever expose the server).

• Run as a single worker. Connection state is held in-process, so do not run

under multiple uvicorn workers — each worker would have its own state.

• Auth credentials are only saved to localStorage when you tick

Remember; otherwise the token is used for the connection but not stored.

Protocol

Uses the official mcp Python SDK, which negotiates the latest MCP protocol version (2025-11-25) during initialization and terminates the session (DELETE /mcp) on disconnect. The negotiated version is reported by /api/status.

License

MIT

Source & license

This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: ventz
• Source: ventz/mcp-explorer
• License: MIT

Install and usage instructions live in the source repository linked above.