import asyncio
from mcp import ClientSession, StdioServerParameters
from mcp.client.stdio import stdio_client
import json

async def main():
    # Start the MCP server as a subprocess and connect to it via stdio
    server_params = StdioServerParameters(command="uv", args=["run", "tax_server.py"])
    async with stdio_client(server_params) as (reader, writer):
        async with ClientSession(reader, writer) as session:
            await session.initialize()  # Handshake with the MCP server

            while True:
                # Simple text menu for the user to choose an action
                print("=== MENU ===")
                print("1. Calculate VAT for a country and price")
                print("2. View VAT rates by country")
                print("3. Get a greeting message")
                print("4. Exit")
                choice = input("Select an option (1/2/3/4): ").strip()

                if choice == "4":
                    break

                elif choice == "1":
                    # Ask the user for the tool's required arguments manually
                    price = float(input("Enter a price: "))
                    country = input("Enter a country: ").strip()

                    # Call the MCP tool directly with the provided arguments
                    tool_response = await session.call_tool(
                        "calculate_tax", {"country": country, "price": price}
                    )
                    result = json.loads(tool_response.content[0].text)
                    print(f"VAT amount: {result['vat_amount']}")
                    print(f"Total price: {result['total_price']}")

                elif choice == "2":
                    # Read an MCP resource exposing all VAT rates
                    resource = await session.read_resource(uri='tax://vat/rates')
                    result = json.loads(resource.contents[0].text)
                    for k, v in result.items():
                        print(f"{k}: {v * 100} %")

                elif choice == "3":
                    # Fetch a pre-written MCP prompt, filled with user-provided values
                    name = input("Enter Your Name: ").strip()
                    country = input("Enter a country: ").strip()
                    prompt = await session.get_prompt(
                        "tax_greeting", {"user_name": name, "country": country}
                    )
                    print(prompt.messages[0].content.text)

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

uv run mcp dev tax_server.py

{
  "mcpServers": {
    "TaxAssistant": {
      "command": "uv",
      "args": [
        "--directory",
        "C:\\Path\\to\\MCP_Server",
        "run",
        "tax_server.py"
      ]
    }
  }
}

async def select_tool(session: ClientSession, user_input: str, history: list[dict]) -> dict:
    # 1. Fetch and render the tool classification prompt using the MCP server
    prompt_result = await session.get_prompt("tool_classifier", {"user_input": user_input})
    rendered_prompt = prompt_result.messages[0].content.text

    # 2. Build the message list (system prompt + recent history + current input) and query Ollama
    messages = [{"role": "system", "content": rendered_prompt}]
    context = history[-4:]
    messages.extend(context)
    messages.append({"role": "user", "content": user_input})

    print("Processing your request with Ollama, this may take a moment...")
    ollama_response = ollama.chat(model="llama3", messages=messages)
    response_text = ollama_response.message.content

    # 3. Clean and parse the model's output into a Python dictionary
    clean = response_text.replace("```json", "").replace("```", "").strip()
    try:
        return json.loads(clean)
    except json.JSONDecodeError:
        return {"error": "Invalid JSON from model"}

Your role is to identify which tool should be used and extract its corresponding arguments.

- Available tools:
    - Name: "tax_calculate"
        - Role: Calculates the VAT/tax amount based on the price and country.
        - Arguments:
            - "price": float
            - "country": str (must be one of: {country_list})

- Output format:
    Respond with valid JSON only - no text, no explanation, no extra characters.
    There are only two possible output formats, both JSON:

    - 1st (when a matching tool is found):
        {
            "tool_name": "tool_name_here",
            "args": {
                "arg1": "value1",
                "arg2": "value2"
            }
        }

    - 2nd (when no matching tool is found):
        {
            "tool_name": null
        }

- Examples:

    - User: "What is the tax on 1000 in Saudi Arabia?"
      Output:
        {
            "tool_name": "tax_calculate",
            "args": {
                "price": 1000,
                "country": "Saudi Arabia"
            }
        }

    - User: "What's the weather like today?"
      Output:
        {
            "tool_name": null
        }

    - User: "What is the VAT on 500 dirhams?"
      Output:
        {
            "tool_name": "tax_calculate",
            "args": {
                "price": 500,
                "country": "UAE"
            }
        }

- Guidelines:
    - Always use the country names exactly as written in this list: [{country_list}]
    - If the country is not mentioned explicitly, try to infer it from context
      (e.g., currency terms like "riyals", "dirhams", "pounds", or location words
      like "Riyadh", "Dubai", "Cairo", etc.)
    - Always include both "price" and "country" in the response.
    - If either is missing or unclear, return: {"tool_name": null}
    - Try to infer the country from currency symbols if the country name is not
      clearly mentioned. For example:
        - SAR → Saudi Arabia
        - AED → UAE

uv run tax_client.py

uv run ./ollama/tax_client_ollama.py

TAX-MCP-AGENT/
├── __pycache__/
├── .venv/
├── ollama/
│   ├── tax_client_ollama.py    # MCP client using Ollama for tool selection
│   └── tax_server_ollama.py    # MCP server variant used by the Ollama client
├── .gitignore
├── .python-version
├── main.py
├── pyproject.toml
├── README.md
├── tax_client.py                # No-LLM interactive test client
├── tax_server.py                # Core MCP server exposing the tax tool/resources/prompts
└── uv.lock