Installation - MCPJam Inspector

MCPJam Inspector runs three ways: a hosted web app, a desktop app for Mac and Windows, or via your terminal. The web app is HTTPS-only and has no install. Terminal and Desktop support HTTP/S and local STDIO servers.

Web App

Open app.mcpjam.com. HTTPS only. No install. Share servers with your team.

Desktop App

Download for Mac or Windows. HTTP/S and local STDIO.

Terminal

npx @mcpjam/inspector@latest. HTTP/S and local STDIO.

Which one do I need?

Capability	Web App	Desktop	Terminal (`npx`)	Docker
Install required	None	Mac/Windows download	Node.js	Docker
HTTPS MCP servers	✓	✓	✓	✓
HTTP MCP servers	—	✓	✓	✓
Local STDIO servers	—	✓	✓	✓ (with `--` args)
Skills	—	✓	✓	✓
Shareable server URLs	✓	—	—	—
Always on latest version	✓	Re-download to update	Per-run (`@latest`)	Per-tag pull

If your server is local (running on localhost), the web app cannot reach it — pick Desktop or Terminal. If you want teammates to one-click into the same server, pick Web App.

Web app

Go to app.mcpjam.com in your browser. No install required. The web app accepts HTTPS MCP server URLs only — for HTTP or local STDIO servers, use the desktop or terminal options below. See Hosted App for more.

Desktop app

Download the installer for your OS and run it:

Mac
Windows

The desktop app supports HTTP/S and local STDIO servers, and does not require Node.js.

Terminal

Run the command in your terminal:

npx @mcpjam/inspector@latest

pnpm dlx @mcpjam/inspector@latest

yarn dlx @mcpjam/inspector@latest

bunx @mcpjam/inspector@latest

After installing the package, you should see a link to localhost. Open that link up to see the inspector.

Widget rendering (Chromium): On first startup, Inspector automatically downloads and installs the Playwright Chromium browser needed to render widgets. This happens in the background — you’ll see download progress in the terminal. No manual playwright install step is required. Docker images already include Chromium and are unaffected.

From your editor (VS Code, Cursor, Windsurf)

There is no dedicated editor extension — and you don’t need one. Open your editor’s integrated terminal, run the same npx @mcpjam/inspector@latest command, and click the printed localhost link. The inspector runs alongside your dev server in any editor that has a terminal pane. If you want the inspector to auto-launch from your project’s dev script (so it boots whenever you start your server), see Launch from Code.

Docker

Run MCPJam Inspector using Docker, bound to localhost for security:

docker run -p 127.0.0.1:6274:6274 mcpjam/mcp-inspector

The app is available at http://127.0.0.1:6274. Always use -p 127.0.0.1:6274:6274 (not -p 6274:6274) to keep the inspector local-only. On macOS/Windows, connect to host MCP servers via http://host.docker.internal:PORT instead of 127.0.0.1.

Docker with Arguments

You can pass command-line arguments to the Docker container:

# Launch with STDIO server
docker run -p 127.0.0.1:6274:6274 mcpjam/mcp-inspector -- \
  npx -y @modelcontextprotocol/server-everything

# Launch with HTTP server
docker run --rm -p 127.0.0.1:6274:6274 mcpjam/mcp-inspector -- \
  --url http://host.docker.internal:8080/mcp \
  --name "HTTP Server" \
  --tab tools

For more information check out our docs on Launch from Code

Important for macOS/Windows users:

Access the app via http://127.0.0.1:6274 (not localhost)
When connecting to MCP servers on your host machine, use http://host.docker.internal:PORT instead of http://127.0.0.1:PORT

Example:

# Your MCP server runs on host at: http://127.0.0.1:8080/mcp
# In Docker, configure it as: http://host.docker.internal:8080/mcp

Start with STDIO server

This will open the MCPJam inspector and connect to a STDIO using the commands you provided.

Python Server
Node.js Server

# Starts MCPJam inspector with a FastMCP server
npx @mcpjam/inspector@latest uv run fastmcp run /path/to/your/server.py

This command assumes uv is installed and on your PATH. If you see Unknown command: uv (fish), command not found: uv (bash/zsh), or 'uv' is not recognized (Windows), install it first:

curl -LsSf https://astral.sh/uv/install.sh | sh

# NPX package
npx @mcpjam/inspector@latest npx -y your-mcp-package

# Direct Node.js execution
npx @mcpjam/inspector@latest node /path/to/your/server.js

Use Absolute Paths: Always use absolute file paths (e.g., /Users/yourname/project/server.py) to avoid path resolution issues.

Start with custom port

This will start the MCPJam inspector with a custom port number. The default port is 6274.

npx @mcpjam/inspector@latest --port 4000

The port must be a valid integer between 1 and 65535. Passing an invalid value (e.g. a string or out-of-range number) exits immediately with an error.

Start with Ollama

This will open the MCPJam inspector and start an Ollama model with the ollama serve <model> command. Make sure you have Ollama installed.

npx @mcpjam/inspector@latest --ollama llama3.2

Start with Configuration File

You can use a configuration file to connect to multiple MCP servers at once:

# Using npx directly
npx @mcpjam/inspector@latest --config path/to/config.json --server myserver

# If running from the repository
npm run build
npm start -- --config path/to/config.json --server myserver

Note: When using npm start, you need the -- separator to pass arguments to the underlying script.

All servers in the config get added to your project. By default they all connect on launch; pass --server <name> to only connect that one. If you’re not signed in, we’ll send you to sign in and bring you right back. Example configuration file structure:

config.json

{
  "mcpServers": {
    "everything": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-everything"],
      "env": {
        "HELLO": "Hello MCP!"
      }
    },
    "weather-server": {
      "command": "python",
      "args": ["weather_server.py"],
      "env": {
        "WEATHER_API_KEY": "your-api-key"
      }
    }
  }
}

Mixing STDIO and HTTP/SHTTP servers

You can mix STDIO and HTTP (Streamable HTTP / SHTTP) server entries in the same config. Each entry’s transport is inferred from its fields: command + args means STDIO, url means HTTP/SHTTP.

config.json

{
  "mcpServers": {
    "local-everything": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-everything"],
      "env": {
        "HELLO": "Hello MCP!"
      }
    },
    "hosted-weather": {
      "url": "https://weather.example.com/mcp",
      "headers": {
        "Authorization": "Bearer YOUR_TOKEN_HERE"
      }
    }
  }
}

The terminal and desktop installs accept both shapes in the same file. The hosted web app accepts HTTP/SHTTP entries only — STDIO entries are ignored because the hosted runtime cannot spawn local processes. For per-server Authorization headers, see API keys → Playground BYOK.

Start with Verbose Logging

Enable verbose HTTP request logging for debugging purposes. This is useful when troubleshooting connection issues with MCP servers.

npx @mcpjam/inspector@latest --verbose

Or use the short form:

npx @mcpjam/inspector@latest -v

Verbose mode logs all HTTP requests made by the inspector, which can help diagnose connectivity problems or inspect server communication.

Web App

Desktop App

Terminal

​Which one do I need?

​Web app

​Desktop app

​Terminal

​From your editor (VS Code, Cursor, Windsurf)

​Docker

​Docker with Arguments

​Start with STDIO server

​Start with custom port

​Start with Ollama

​Start with Configuration File

​Mixing STDIO and HTTP/SHTTP servers

​Start with Verbose Logging

Which one do I need?

Web app

Desktop app

Terminal

From your editor (VS Code, Cursor, Windsurf)

Docker

Docker with Arguments

Start with STDIO server

Start with custom port

Start with Ollama

Start with Configuration File

Mixing STDIO and HTTP/SHTTP servers

Start with Verbose Logging