MCP Client for Testing

A minimalistic MCP (Model Context Protocol) client for testing tool calls in MCP servers.

Usage

Install uv and test a tool call in an MCP server like this:

uvx mcp-client-for-testing \
    --config '
    [
        {
            "name": "name of mcp server",
            "command": "uv",
            "args": [
                "--directory", 
                "path/to/root/dir/", 
                "run", 
                "server.py"
            ],
            "env": {}
        }
    ]
    ' \
    --client_log_level "WARNING" \
    --server_log_level "INFO" \
    --tool_call '{"name": "tool-name", "arguments": {}}'

To use it in code, install the package:

uv pip install mcp-client-for-testing 

and use it like this:

import asyncio

from mcp_client_for_testing.client import execute_tool

async def main():
    config = [
        {
            "name": "name of mcp server",
            "command": "uv",
            "args": [
                "--directory", 
                "path/to/root/dir/", 
                "run", 
                "server.py"
            ],
            "env": {}
        }
    ]
    tool_call = {"name": "tool-name", "arguments": {}}
    
    await execute_tool(config, tool_call)

if __name__ == "__main__":
    asyncio.run(main())

Example

Use the echo-mcp-server-for-testing with uvx to test the MCP client.

uvx mcp-client-for-testing \
    --config '
    [
        {
            "name": "echo-mcp-server-for-testing",
            "command": "uvx",
            "args": [
                "echo-mcp-server-for-testing"
            ],
            "env": {
                "SECRET_KEY": "123456789"
            }
        }
    ]
    ' \
    --client_log_level "WARNING" \
	--server_log_level "INFO" \
    --tool_call '{"name": "echo_tool", "arguments": {"message": "Hello, world!"}}'

Development

Installation from source

1. Clone the repo git clone git@github.com:piebro/mcp-client-for-testing.git.
2. Go into the root dir cd mcp-client-for-testing.
3. Install in development mode: uv pip install -e .

Formatting and Linting

The code is formatted and linted with ruff:

uv run ruff format
uv run ruff check --fix

Building with uv

Build the package using uv:

uv build

Releasing a New Version

To release a new version of the package to PyPI, create and push a new Git tag:

1. Checkout the main branch and get the current version:

   git checkout main
   git pull origin main
   git describe --tags
   

2. Create and push a new Git tag:

   git tag v0.2.0
   git push origin v0.2.0
   

The GitHub Actions workflow will automatically build and publish the package to PyPI when a new tag is pushed. The python package version number will be derived directly from the Git tag.

License

This project is licensed under the MIT License. See the LICENSE file for details.