MCP Test

Small Python workspace for experimenting with Model Context Protocol (MCP) servers, clients, gateways, and third-party MCP integrations.

The repository contains examples for:

• Creating a local MCP server with FastMCP
• Connecting to an MCP server over stdio
• Running an MCP server over streamable HTTP
• Loading MCP tools through LangChain MCP adapters
• Trying community/third-party MCP servers such as DuckDuckGo, Tavily, and AWS ECS
• Mounting/proxying external MCP servers behind a FastMCP gateway

Project Structure

.
|-- create_mcp/
|   |-- first_mcp_server_stdio.py   # Local stdio FastMCP server
|   |-- python_client.py            # Native MCP stdio client
|   `-- langchain_client.py         # LangChain MCP client for stdio server
|-- http_mcp/
|   |-- http_mcp.py                 # FastMCP HTTP server on port 8050
|   `-- langchain_client.py         # LangChain client for stdio + HTTP MCP servers
|-- 3rd party mcp/
|   |-- community_mcp.py            # DuckDuckGo MCP server example
|   |-- tavily_mcp.py               # Tavily remote MCP example
|   |-- aws.py                      # AWS ECS MCP + Groq model example
|   `-- aws_tools_llm.py            # AWS ECS MCP + LangGraph/Gemini example
|-- 4th_mcp_gateway/
|   `-- mcp.py                      # FastMCP gateway/proxy example
|-- main.py                         # Minimal Python entry point
|-- pyproject.toml                  # Python project metadata and dependencies
|-- package.json                    # Basic Node package metadata
`-- uv.lock                         # uv lockfile

Requirements

• Python >=3.14 as configured in pyproject.toml
• uv for dependency installation and running scripts
• uvx for examples that launch third-party MCP servers
• API keys for examples that call hosted LLMs or remote MCP services
• AWS credentials/profile for AWS ECS MCP examples

Setup

Install dependencies:

uv sync

Activate the virtual environment if you want to run Python directly:

.\.venv\Scripts\Activate.ps1

Or run scripts through uv run, which uses the project environment automatically.

Environment Variables

Create a local .env file for secrets used by remote examples. This file is ignored by git and should stay only on your machine.

TAVILY_API_KEY="your-tavily-api-key"
GROQ_API_KEY="your-groq-api-key"
GOOGLE_API_KEY="your-google-api-key"
AWS_REGION="ap-south-1"

Do not commit real API keys. If you want to share required environment variables with other developers, create an .env.example file with placeholder values. .env.example is allowed by .gitignore, while .env and .env.* remain ignored.

Some prototype scripts currently contain hard-coded local paths or credentials; replace those with environment variables before sharing or using the project beyond local testing.

Running the Examples

Basic project entry point

uv run python main.py

Local stdio MCP server

Start the server:

uv run python .\create_mcp\first_mcp_server_stdio.py

The server exposes two tools:

• fetch
• process

Native Python stdio client

This client starts first_mcp_server_stdio.py, initializes an MCP session, and prints the available tools.

uv run python .\create_mcp\python_client.py

LangChain stdio client

uv run python .\create_mcp\langchain_client.py

Before running, update the hard-coded Python executable and script paths in the file so they match your local checkout.

HTTP MCP server

Start the HTTP server:

uv run python .\http_mcp\http_mcp.py

The server listens on:

http://localhost:8050/mcp

It exposes:

• http_fetch
• http_process

LangChain HTTP client

In another terminal, after starting the HTTP server:

uv run python .\http_mcp\langchain_client.py

This example loads tools from both the local stdio server and the HTTP MCP server.

DuckDuckGo community MCP example

uv run python '.\3rd party mcp\community_mcp.py'

This uses uvx duckduckgo-mcp-server, loads the exposed tools, and invokes the first search tool.

Tavily remote MCP example

Set TAVILY_API_KEY in .env, then run:

uv run python '.\3rd party mcp\tavily_mcp.py'

This connects to Tavily's remote MCP endpoint and lists available tools.

AWS ECS MCP examples

These examples launch the AWS Labs ECS MCP server through uvx:

uv run python '.\3rd party mcp\aws.py'
uv run python '.\3rd party mcp\aws_tools_llm.py'

You need valid AWS configuration before running them. The Groq example reads GROQ_API_KEY from .env, and the Gemini/LangGraph example reads GOOGLE_API_KEY from .env.

For write-capable operations, review the AWS ECS MCP server settings carefully before enabling any write or sensitive-data options.

MCP gateway/proxy

uv run python .\4th_mcp_gateway\mcp.py

This starts a FastMCP HTTP server on port 8050 and mounts a proxied external MCP server.

Notes

• create_mcp/langchain_client.py and http_mcp/langchain_client.py include absolute Windows paths from the original local environment. Update them to use your current project path before running.
• 3rd party mcp/tavily_mcp.py expects TAVILY_API_KEY from .env.
• 3rd party mcp/aws.py expects GROQ_API_KEY from .env.
• 3rd party mcp/aws_tools_llm.py expects GOOGLE_API_KEY from .env.
• Some scripts reference packages such as python-dotenv or langgraph; install them if your current lockfile does not include them.
• package.json is present, but the working examples in this repository are Python based.

Security Checklist

• Keep .env out of git.
• Use .env.example for non-secret placeholders when documenting required variables.
• Replace hard-coded API keys with environment variables.
• Avoid committing local machine paths.
• Review third-party MCP tool permissions before connecting them to an LLM agent.