Echo MCP Server For Testing

A simple echo MCP (Model Context Protocol) Server for testing MCP Clients.

python

2

GitHub Stars

python

Language

6 months ago

First Indexed

2 months ago

Catalog Refreshed

Documentation & install

Readme and setup notes from the catalogue, plus a client-ready config you can copy for your MCP host.

Installation

Add the following to your MCP client configuration file.

Configuration

View docs

{
  "mcpServers": {
    "piebro-echo-mcp-server-for-testing": {
      "command": "uvx",
      "args": [
        "echo-mcp-server-for-testing"
      ],
      "env": {
        "SECRET_KEY": "123456789"
      }
    }
  }
}

You can run a lightweight echo MCP server to test MCP clients and explore basic MCP interactions. This server echoes input through a simple tool, making it ideal for verifying client handshakes, round-trips, and integration flows without building a full backend.

How to use

To use the echo MCP server, add it to your MCP configuration so your client can connect and send test messages. You can run it as a local process that your MCP client talks to, or run it via a managed tool launcher that starts the server in a controlled environment.

How to install

Prerequisites you need before starting the server are Python (for the Python-based script) and the MCP launcher utilities you use to run MCP servers (such as uv/uvx). Install Python from the official site and ensure it is available on your PATH.

Option A: run via a local launcher with uvx to start the server by name. Use the following configuration to register the server for MCP use. The environment key SECRET_KEY is required for this setup.

{
  "name": "echo-mcp-server-for-testing",
  "command": "uvx",
  "args": ["echo-mcp-server-for-testing"],
  "env": {
    "SECRET_KEY": "123456789"
  }
}

Option B: run via a directory with a Python entry point (for example a main.py script) using the standard launcher. This approach also requires the SECRET_KEY and exposes the server locally for MCP clients to connect.

{
  "name": "echo-mcp-server-for-testing",
  "command": "uv",
  "args": [
    "--directory",
    "path/to/root/dir/",
    "run",
    "main.py"
  ],
  "env": {
    "SECRET_KEY": "123456789"
  }
}

Additional configuration and notes

The server exposes an echo tool for testing. You can exercise the echo_tool by issuing test tool calls from your MCP client to verify message flow and response handling.

If your setup requires testing through client tooling, you can pair the server with a test client that sends a message through the echo_tool and checks that the response matches expectations.

Troubleshooting and tips

Ensure the SECRET_KEY is passed to the server environment exactly as shown and that the MCP launcher you use can access the server's start command. If you encounter connection failures, verify that your MCP client is configured to reach the server on the correct host and port as exposed by your launcher.

Security considerations

Keep the SECRET_KEY secret and rotate it if you believe it may have been exposed. Run the server in a controlled environment and limit access to the host running the MCP server during testing.

Examples and quick reference

Two common ways to start the echo MCP server are shown here. Choose the method that matches your environment and launcher.

Tooling and capabilities

Tools available for testing include the echo_tool, which echoes back messages and helps validate client behavior during development and testing.

Available tools

echo_tool

A simple MCP tool that echoes back the input to test client interactions and message round-trips.