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 and WiFi (TCP) — 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

graph LR
    A["Claude / LLM"]
    B["mcpu-client (npm)<br/>Dynamic tool regist."]
    C["MCU Firmware<br/>MCP-U lib"]

    A <-->|"MCP (stdio)"| B
    B <-->|"Serial / TCP"| C

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 <MCP-U.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 (`volts` on ESP32, `mv` on AVR)

Firmware API →

The complete McpDevice API: pins, tools, transport, and error handling. Read reference

Client Setup →

Configure the TypeScript MCP client for any AI agent. Read guide