Arduino Agent

The AI-native Arduino IDE. Arduino Agent is a full Arduino IDE 2.x with a Model Context Protocol (MCP) server built into its core — so an AI agent like Claude can write sketches, compile them, upload to real boards, read the serial monitor, and manage libraries alongside you, editing the same files you see in the editor in real time.

There's no plugin to install into the AI, no sidecar process, no copy-pasting code back and forth. The IDE itself is the agent's workbench. You launch it, point your assistant at http://127.0.0.1:3847, and the two of you share one editor, one board, one serial monitor.

_{Built on Arduino IDE 2.x · An independent community project, not affiliated with or endorsed by Arduino SA · AGPL-3.0}

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Why it exists

The Arduino IDE is where embedded projects get built. Modern AI agents are great at embedded code — but they work blind, guessing at your board, your errors, and your wiring, and handing you snippets to paste. Arduino Agent closes that gap by making the IDE a first-class participant in the conversation:

• The agent sees what you see — the open sketch, the selected board and port, connected devices, and real compiler output (not a guess).
• You see what the agent does — when it writes a file, the editor opens it, reloads it, and shows a "Created by Claude" notification. True pair programming on hardware.
• It drives the real toolchain — the same arduino-cli, clang-format, and serial monitor the IDE uses. Compile results, memory usage, and upload status are the genuine article.

Download

Latest release: v0.5.2 — unsigned development builds:

• Windows x64
• macOS
• Linux x64

Unzip and run Arduino IDE (Arduino IDE.exe on Windows). Older builds are on the Releases page.

These are unsigned dev builds. On macOS you may need to allow the app under System Settings → Privacy & Security; on Windows, dismiss SmartScreen with More info → Run anyway. Prefer to build it yourself? See Building from source.

Quick start — connect your agent

1. Launch the IDE. The MCP server starts automatically on http://127.0.0.1:3847 and prints a ready-to-paste client configuration — including your auth token — to the console.

2. Add it to your MCP client. For Claude Code / Claude Desktop, drop this into your .mcp.json (the token lives in ~/.arduinoIDE/mcp-token):

   {
     "mcpServers": {
       "arduino": {
         "type": "http",
         "url": "http://127.0.0.1:3847/mcp",
         "headers": { "Authorization": "Bearer <your-token>" }
       }
     }
   }

3. Talk to your board.

   • "Create a Blink sketch and open it."
   • "What boards are connected?"
   • "Compile for the Uno and explain any errors."
   • "Upload it, then show me the serial output at 115200."

What the agent can do

Category	Operations
Sketches	Create, open, and edit sketches; read/write code; browse and clone built-in examples
Build	Compile with live progress; capture real compiler output and structured errors
Upload	Flash firmware to a connected board (guarded as a destructive action)
Boards	Detect connected boards; query pin capabilities (PWM/I2C/SPI); install cores
Serial	Connect, read, and write the serial monitor — shared with the IDE's own monitor
Libraries	Search the registry; install/remove; browse library examples
Formatting	Format Arduino/C++ with clang-format
Config	Sketchbook location, board-manager URLs, IDE settings

By default the tools are exposed through a router pattern — 4 meta-tools (list_tool_categories, get_category_tools, execute_tool, search_tools) so the agent discovers tools on demand instead of loading every definition into its context. A direct mode exposes all tools individually if you prefer.

How it works

+------------------+     HTTP (Bearer auth)     +---------------------------+
|    AI agent      | <------------------------> |      Arduino Agent        |
|  (MCP client)    |   http://127.0.0.1:3847    |  (Theia/Electron + MCP)    |
+------------------+           /mcp             +------------------------------+
                                                      |
                                             Arduino toolchain
                                        (arduino-cli daemon, clang-format,
                                         pluggable serial monitor)

The MCP server is embedded in the IDE's backend and speaks the modern Streamable HTTP transport (plus legacy SSE for older clients), supporting multiple simultaneous sessions.

Security is on by default:

• Binds to 127.0.0.1 only.
• Requires a bearer token (generated on first launch, stored in ~/.arduinoIDE/mcp-token).
• Rejects browser-originated requests and sends no CORS headers, so a web page can't reach it.
• Confines file access to your sketchbook and the built-in examples.

The only unauthenticated endpoint is a health check:

curl http://127.0.0.1:3847/health

Settings

File → Preferences → MCP:

Setting	Description	Default
Enable MCP server	Turn the integration on/off	true
Start automatically	Launch the server with the IDE	true
Server port	HTTP port (1024–65535)	3847
Require auth	Require the bearer token	true
Log level	none / error / info / debug	info
Tool mode	Router (4 meta-tools) or Direct (all tools)	router

Made for learning, too

Arduino Agent ships extras aimed at STEM and classroom use:

• Example browser — every built-in Arduino example, with descriptions.
• Hardware reference — ask for a board's pin map, PWM/I2C/SPI pins, memory.
• Beginner-friendly errors — compiler errors returned with plain-language explanations and suggested fixes.

It also carries a modernized UI (refined buttons, dialogs, board selector, progress bars, and serial monitor) that respects both light and dark themes.

Building from source

Prerequisites: Node.js 18+, Yarn 4 (via Corepack), Python 3.11, Go 1.21, and a C/C++ toolchain (VS 2022 Build Tools on Windows).

git clone https://github.com/mixelpixx/arduino-mcp.git
cd arduino-mcp

corepack enable
yarn install
yarn prepare:shims      # create the launcher shims Theia's build expects

yarn build:dev          # build all packages, including the MCP extension
cd electron-app && yarn start

Windows has a few extra native-module notes (mostly automated now) — see docs/BUILDING-WINDOWS.md. Full extension documentation lives in arduino-mcp-extension/README.md.

Project status

Actively developed. Verified working end-to-end: the MCP server and auth, IDE-state sync, sketch create/read/write with live editor reload, compile with real captured output, and all read-only tools. Upload and live serial are implemented and need a physical board to fully exercise. The Windows build is verified from source and installed; the macOS and Linux release builds are newer and still being hardened.

Contributions and bug reports are welcome via Issues and pull requests.

Relationship to the Arduino IDE

Arduino Agent is a fork of the open-source Arduino IDE 2.x (a Theia/Electron application that drives the arduino-cli). All of the core IDE work is theirs; this project adds the embedded MCP server, the AI-collaboration features, and the UI refinements on top.

Arduino® is a trademark of Arduino SA. Arduino Agent is an independent, community project and is not affiliated with, sponsored by, or endorsed by Arduino SA. The name describes this project's purpose — an agent-driven Arduino development environment — and implies no official connection.

License

Licensed under the GNU AGPL-3.0-or-later, the same license as the upstream Arduino IDE. Distributions include third-party components under compatible licenses (GPLv2, MIT, BSD-3). See LICENSE.txt.