mcp-agent-kit

A pure standard-library Model Context Protocol (MCP) server & tool harness for Claude Desktop, Cursor, and autonomous agent fleets.

Quickstart • Architecture • Claude Desktop Setup • Comparison • Engineering Rigor

Architecture

Related MCP server: MCP-123

Why mcp-agent-kit?

The official MCP SDKs introduce dozens of heavy third-party dependencies (pydantic, anyio, httpx, starlette), creating unnecessary supply-chain attack surfaces and installation friction in enterprise environments.

mcp-agent-kit provides a complete, production-ready implementation of the Model Context Protocol using 100% Python Standard Library:

• 🚀 Zero Runtime Dependencies: Pure Python (json, sys, inspect, dataclasses).

• 🔒 Enterprise-Ready: Instant auditability with zero package vulnerability exposure.

• ⚡ Ultra Lightweight: <5MB package memory overhead with no dependency resolution delay, ideal for CLI tools, serverless environments, and embedded forward-deployed agent integrations.

• 🛠️ Automatic Schema Generation: Infers JSON Schema definitions directly from native Python type hints and docstrings.

mcp-agent-kit vs Official MCP SDK

Quickstart

1. Build an MCP Server in 20 Lines

from mcp_agent_kit import MCPServer

app = MCPServer(name="my-agent-tools", version="1.0.0")

@app.tool(description="Calculate tax and total invoice amounts")
def calculate_invoice(subtotal: float, tax_rate: float = 0.07) -> dict:
    tax = round(subtotal * tax_rate, 2)
    return {"subtotal": subtotal, "tax": tax, "total": round(subtotal + tax, 2)}

if __name__ == "__main__":
    app.run_stdio()

Claude Desktop Integration

Add your server directly to claude_desktop_config.json:

{
  "mcpServers": {
    "my-tools": {
      "command": "python",
      "args": ["-m", "examples.simple_server"]
    }
  }
}

Restart Claude Desktop, and your custom tools will immediately appear in Claude's tool belt! 🔨

Features

• Full MCP Handshake: initialize, notifications/initialized, ping.

• Dynamic Tool Discovery: tools/list with automatic JSON schema generation.

• Robust Error Boundaries: tools/call isolates tool runtime exceptions and reports structured error messages back to the LLM without crashing the stdio process.

• Zero Dependencies: Runs out of the box on Python 3.10+.

Engineering Rigor & Verification

• Tests: 100% passing pytest test suite covering initialization, tool discovery, argument validation, and exception handling.

• Dependencies: 0 runtime dependencies.

• Author: Reuben Bowlby — LinkedIn | Resume

Enterprise Scale

mcp-agent-kit is part of the HUMMBL developer ecosystem. For enterprise-grade multi-agent governance (4-stage kill switches, HMAC-signed delegation tokens, and cryptographic audit buses), visit github.com/hummbl-io.