MCP Log Proxy

v1.0.0โ€ขDeveloper Toolsโ€ขstable

๐ŸŽ๏ธ ๐Ÿ  - MCP server proxy that offers a Web UI to the full message flow

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What is MCP Log Proxy?

MCP Log Proxy is a Model Context Protocol (MCP) server that allows AI assistants like Claude, Cursor, and VS Code to ๐ŸŽ๏ธ ๐Ÿ  - mcp server proxy that offers a web ui to the full message flow

๐ŸŽ๏ธ ๐Ÿ  - MCP server proxy that offers a Web UI to the full message flow

This server falls under the Developer Tools category on MCPgee, the world's largest MCP server directory with 33,000+ servers.

Features

  • ๐ŸŽ๏ธ ๐Ÿ  - MCP server proxy that offers a Web UI to the full mes

Use Cases

Debug MCP message flows with a web UI for full visibility.
Monitor and inspect all MCP server interactions.
emicklei

Maintainer

LicenseMIT
Languagego
Versionv1.0.0
UpdatedApr 26, 2026
Statushealthy
Maintenanceactive

Works with

ClaudeOpenAIwindowsmacoslinux

Installation

Manual Installation

npx mcp-log-proxy

Configuration

Configuration Details

Config File

claude_desktop_config.json

Performance

Response Metrics

Response Time< 200ms
ThroughputMedium

Resource Usage

Memory UsageLow
CPU UsageLow

How to Set Up and Use MCP Log Proxy

MCP Log Proxy is a transparent stdio proxy for MCP servers that captures every JSON-RPC message exchanged between an MCP client and server and makes them visible through a local web UI at http://localhost:5656. It sits between your MCP client (such as Claude Desktop) and the actual MCP server binary, forwarding messages unchanged while logging the full message flow in real time. Developers use it to debug tool call payloads, inspect error responses, trace unexpected behavior, and monitor multiple concurrent MCP server instances โ€” each proxy registers itself in ~/.mcp-log-proxy-instances.json and the web UI lets you switch between them.

Prerequisites

  • Go 1.21 or higher (for go install method), or Homebrew on macOS
  • An existing MCP server to proxy (e.g., any stdio-based MCP server)
  • Claude Desktop or another MCP client configured to use stdio transport
  • A web browser to view the log UI at http://localhost:5656
1

Install mcp-log-proxy

Install via Homebrew on macOS or directly with Go.

# macOS via Homebrew:
brew tap emicklei/tap
brew install emicklei/tap/mcp-log-proxy

# Or via Go:
go install github.com/emicklei/mcp-log-proxy@latest
2

Identify the MCP server you want to proxy

Find the full command for the MCP server you want to inspect. You will wrap this command with mcp-log-proxy.

# Example: proxying the melrose-mcp server
which melrose-mcp
# /Users/yourname/go/bin/melrose-mcp
3

Test the proxy from the command line

Run mcp-log-proxy with the -command flag pointing to the target MCP server. Messages will be visible at http://localhost:5656.

mcp-log-proxy -command melrose-mcp
4

Update your Claude Desktop configuration to use the proxy

Replace the direct server command with mcp-log-proxy, passing the original server command via the -command argument.

5

Open the web UI to inspect messages

Open a browser to http://localhost:5656 to see the live MCP message flow. Use the selector to switch between multiple proxy instances if you are proxying more than one server.

MCP Log Proxy Examples

Client configuration

Claude Desktop config that wraps the browsermcp server with mcp-log-proxy for debugging, logging to a file and exposing the web UI on port 7799.

{
  "mcpServers": {
    "browsermcp": {
      "command": "/Users/yourname/go/bin/mcp-log-proxy",
      "args": [
        "-command",
        "npx @browsermcp/mcp@latest",
        "-log",
        "/Users/yourname/Library/Logs/claude-browsermcp-proxy.log",
        "-port",
        "7799",
        "-title",
        "Claude Browser MCP"
      ]
    }
  }
}

Prompts to try

mcp-log-proxy is a debugging tool โ€” use these approaches to inspect MCP traffic while interacting with the proxied server normally through Claude.

- Open http://localhost:5656 in your browser, then ask Claude any question that triggers the proxied server's tools
- "List all files in the current directory" (when proxying a filesystem MCP server)
- After each Claude response, refresh the proxy web UI to see the exact JSON-RPC tool call and result payloads
- Run two proxies on different ports (e.g. -port 7788 and -port 7799) and use the web UI selector to switch between them

Troubleshooting MCP Log Proxy

Web UI at http://localhost:5656 shows no messages

Ensure the proxy is running (it starts when Claude Desktop launches the MCP server). Trigger a tool call from Claude Desktop and then refresh the browser. If port 5656 is taken by another process, mcp-log-proxy will auto-select a different port โ€” check the proxy's startup output or ~/.mcp-log-proxy-instances.json for the actual port.

Port conflict when running multiple proxies

mcp-log-proxy automatically detects port conflicts and picks a different port. Use the -port flag explicitly on each proxy instance to assign fixed ports (e.g., -port 7788 and -port 7799). All instances are discoverable through the web UI's instance selector.

The proxied MCP server fails to start when wrapped with mcp-log-proxy

Ensure the command passed to -command is available on the PATH that Claude Desktop uses (which may differ from your shell PATH). Use full absolute paths for both mcp-log-proxy and the target server command in the Claude Desktop config.

Frequently Asked Questions about MCP Log Proxy

What is MCP Log Proxy?

MCP Log Proxy is a Model Context Protocol (MCP) server that ๐ŸŽ๏ธ ๐Ÿ  - mcp server proxy that offers a web ui to the full message flow It connects AI assistants to external tools and data sources through a standardized interface.

How do I install MCP Log Proxy?

Follow the installation instructions on the MCP Log Proxy GitHub repository. Clone the repo, install dependencies, and add the server config to your AI client.

Which AI clients work with MCP Log Proxy?

MCP Log Proxy works with all major MCP-compatible AI clients including Claude Desktop, Claude Code, Cursor, VS Code (GitHub Copilot), Windsurf, and Cline.

Is MCP Log Proxy free to use?

Yes, MCP Log Proxy is open source and available under the MIT license. You can use it freely in both personal and commercial projects.

Browse More Developer Tools MCP Servers

Explore all developer tools servers available in the MCPgee directory. Each server includes setup guides for Claude, Cursor, and VS Code.

Quick Config Preview

{ "mcpServers": { "mcp-log-proxy": { "command": "npx", "args": ["-y", "mcp-log-proxy"] } } }

Add this to your claude_desktop_config.json or .cursor/mcp.json

Read the full setup guide โ†’

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