MCP/U

Transform any Arduino-compatible MCU into an AI-ready device via the Model Context Protocol.

Quick Start GitHub

⚡ by 2edge.co · LGPL-3.0

Why MCP/U?

Self-Describing Firmware

Devices auto-declare their tools via JSON Schema. The client registers tools dynamically — zero hardcoded names.

Universal Transport

Serial, WiFi (TCP), and Bluetooth — one library, one API, any Arduino Stream.

Minimalist Integration

Just add_pin(), add_tool(), begin(). No protocol complexity in your sketch.

Multi-Device Ready

Connect any number of MCUs to a single MCP client. Tools auto-namespaced per device.

How It Works

┌─────────────────┐        ┌──────────────────────┐        ┌───────────────┐
│  Claude / LLM   │◄─MCP──►│  mcpu-client (npm)   │◄─────►│  MCU Firmware │
│                 │  stdio │  Dynamic tool regist. │ Serial │  McpIot lib   │
└─────────────────┘        └──────────────────────┘   /TCP └───────────────┘

Client connects to MCU over Serial or TCP
Calls list_tools — MCU responds with full tool + pin registry (JSON Schema)
Client dynamically registers one MCP tool per MCU tool
Claude can now call any MCU tool by name

3-Step Setup

#include <McpIot.h>

McpDevice mcp("my-device", "1.0.0");

void setup() {
  mcp.add_pin(2,  "led",    MCP_DIGITAL_OUTPUT, "Onboard LED");
  mcp.add_pin(34, "sensor", MCP_ADC_INPUT,      "Analog Sensor");
  mcp.begin(Serial, 115200);
}

void loop() { mcp.loop(); }

claude mcp add mcpu -e SERIAL_PORT=/dev/ttyACM0 -- npx mcpu-client

{
  "mcpServers": {
    "mcpu": {
      "command": "npx",
      "args": ["mcpu-client"],
      "env": { "SERIAL_PORT": "/dev/ttyACM0" }
    }
  }
}

Built-in Tools

Every device running MCP/U exposes these tools automatically:

Tool	Description
`list_tools`	Discovery: tools + pin registry
`get_info`	Device name, version, platform
`gpio_write`	Set digital output HIGH / LOW
`gpio_read`	Read digital level
`pwm_write`	PWM output (duty 0–255)
`adc_read`	Read ADC value (0–4095)

Firmware Guide →

Install the McpIot library and learn the full API. Get started

Client Guide →

Set up the TypeScript MCP client and connect to Claude. Get started