I made PolyMCP so I could quickly turn normal functions (Python or TypeScript) into MCP tools without much extra work.
Python example:
from polymcp.polymcp_toolkit import expose_tools
def greet(name: str) -> str:
"""Say hello."""
return f"Hello, {name}!"
def add(a: int, b: int) -> int:
"""Add two numbers."""
return a + b
app = expose_tools([greet, add], title="My MCP Tools")
Run with:
uvicorn server:app --reload
MCP endpoints appear at /mcp/list_tools and /mcp/invoke/.
TypeScript example:
import { z } from 'zod';
import { tool, exposeTools } from 'polymcp';
const uppercaseTool = tool({
name: 'uppercase',
description: 'Convert text to uppercase',
inputSchema: z.object({ text: z.string() }),
function: async ({ text }) => text.toUpperCase(),
});
const app = exposeTools([uppercaseTool], { title: "Text Tools" });
app.listen(3000);
Business example (Python):
import pandas as pd
from polymcp.polymcp_toolkit import expose_tools
def calculate_commissions(sales_data: list[dict]):
df = pd.DataFrame(sales_data)
df["commission"] = df["sales_amount"] * 0.05
return df.to_dict(orient="records")
app = expose_tools([calculate_commissions], title="Business Tools")
What you get:
• Reuse existing code with minimal changes
• Compatible with MCP clients (Claude Desktop, agents, Ollama, etc.)
• HTTP and stdio and Wasm support
• Automatic validation
• Basic production features (budgets, retries, redaction, logs)
• Inspector: polymcp inspector for testing/monitoring
Install:
• Python: pip install polymcp
• TypeScript: clone repo → cd polymcp-ts → npm install → npm run build
Repo: https://github.com/poly-mcp/Polymcp
Curious what kind of function people would expose first if it was this simple. Feedback welcome.
