---
title: "MCP for Raspberry Pi Pico W"
url: "https://maker.wiznet.io/matthew/projects/mcp-for-raspberry-pi-pico-w/"
markdown_url: "https://maker.wiznet.io/matthew/projects/mcp-for-raspberry-pi-pico-w/md"
type: "UCC: User Created Content"
author: "Hiroaki Nagashima"
author_url: "https://github.com/h7ga40/pico_mcp_wireguard"
editor: "WIZnet"
editor_url: "https://maker.wiznet.io/"
original_author: "Hiroaki Nagashima"
original_url: "https://github.com/h7ga40/pico_mcp_wireguard"
published: "2025-09-16"
language: "en"
hardware: ["WIZnet W55RP20-EVB-Pico"]
likes: 0
views: 4324
comments: 0
source: "WIZnet Makers (https://maker.wiznet.io/)"
---

# MCP for Raspberry Pi Pico W

> Pico W MCP firmware with JSON-RPC tools and WireGuard-ready build; build via Pico SDK and toggle the onboard LED from an agent.

Original author: Hiroaki Nagashima (source: https://github.com/h7ga40/pico_mcp_wireguard)

## Components

- **WIZnet W55RP20-EVB-Pico** x 1 ([docs](https://wiznet.io/products/powered-by-raspberry-pi/w55rp20-evb-pico))

## Documents and links

- [Source](https://github.com/h7ga40/pico_mcp_wireguard) (code)

## Article

## Overview

This project delivers an **MCP (Model Context Protocol)–oriented firmware** for the **Raspberry Pi Pico W**. It exposes device capabilities as **JSON-RPC tools** so an IDE agent (e.g., Copilot Chat) can remotely perform actions like **toggling the onboard LED**. The repo includes **PICO-SDK build instructions** and a **WireGuard import script** to scaffold a secure tunnel around MCP traffic for remote operation scenarios. ([GitHub](https://github.com/h7ga40/pico_mcp_wireguard))

---

## Original Language & Author

The source is written in **English** and maintained by **@h7ga40**. The README outlines an **agent-driven workflow** (VS Code Copilot Chat) that invokes the device’s JSON-RPC tools, making it a practical bridge between **LLM/IDE agents** and **embedded targets**. ([GitHub](https://github.com/h7ga40/pico_mcp_wireguard))

---

## Key Highlights

**JSON-RPC tool surface (LED control)**
The firmware exposes `tools/list` and `tools/call` with three tools: `set_location`, `set_switch_id`, and `set_switch`. Typical sequence: set a location and switch id, then call `set_switch` with `"on"`/`"off"` to toggle the LED. The LED changes only when the request’s `location`/`switch_id` matches prior settings (or both are omitted). ([GitHub](https://github.com/h7ga40/pico_mcp_wireguard))

**Agent workflow**
Intended to run under **GitHub Copilot Chat (agent mode)** in VS Code; the repo references a short flow (“how_it_works.mp4”). ([GitHub](https://github.com/h7ga40/pico_mcp_wireguard))

**PICO-SDK setup & environment**
The README summarizes installing **pico-sdk 2.2.0** under `~/.pico-sdk/sdk/2.2.0` and exporting `PICO_SDK_PATH` accordingly. ([GitHub](https://github.com/h7ga40/pico_mcp_wireguard))

**Build in a few commands**

```plaintext
mkdir build
cd build
cmake -E env PICO_SDK_FETCH_FROM_GIT=1 cmake ..
make -j$(nproc)
```

On success, artifacts like `**pico_mcp.uf2**` appear in `build/`. ([GitHub](https://github.com/h7ga40/pico_mcp_wireguard))

**Networking stack & WireGuard scaffold**
The tree includes **llhttp** (HTTP parser), **parson** (JSON), `lwipopts.h` for **lwIP**, and a CMake import named `**pico_wireguard_import.cmake**`—handy if you want to protect MCP traffic through a **WireGuard VPN**. (WireGuard key/peer setup is not yet documented in the repo.) ([GitHub](https://github.com/h7ga40/pico_mcp_wireguard))

---

## Why It Matters (Curator’s View)

**Hands-on with modern control patterns:** Recreate the **MCP** model—an IDE/LLM agent calls device “tools” over JSON-RPC—on real hardware. ([GitHub](https://github.com/h7ga40/pico_mcp_wireguard))

**Security-ready architecture:** The WireGuard import script hints at a clean path to **VPN-protected remote control**, ideal for field boxes, labs, or home setups. ([GitHub](https://github.com/h7ga40/pico_mcp_wireguard))

**Lean networking practice:** Work directly with **lwIP + llhttp + parson** to internalize JSON-RPC control beyond classic REST-style sketches. ([GitHub](https://github.com/h7ga40/pico_mcp_wireguard))

**MIT-licensed starting point:** Easy to repurpose for commercial/education use, with a clear template to add more tools (GPIO, I²C, SPI, sensors). ([GitHub](https://github.com/h7ga40/pico_mcp_wireguard))

---

## Quick Reproduce (Checklist)

**Install PICO-SDK** under `~/.pico-sdk/sdk/2.2.0` and set `PICO_SDK_PATH`. ([GitHub](https://github.com/h7ga40/pico_mcp_wireguard))

**Build**

```plaintext
mkdir build && cd build
cmake -E env PICO_SDK_FETCH_FROM_GIT=1 cmake ..
make -j$(nproc)
```

Expect `**pico_mcp.uf2**` in `build/`. ([GitHub](https://github.com/h7ga40/pico_mcp_wireguard))

**Flash & run**: Copy the UF2 via BOOTSEL.

**Call tools**: Use `tools/list` to discover tools, then call `set_location` → `set_switch_id` → `set_switch` to toggle the LED. ([GitHub](https://github.com/h7ga40/pico_mcp_wireguard))

**(Optional) Secure tunnel**: Use `**pico_wireguard_import.cmake**` as a starting point to integrate WireGuard and test MCP over a VPN. ([GitHub](https://github.com/h7ga40/pico_mcp_wireguard))

---

## Next-Step Ideas

**Expand the toolset:** Add JSON-RPC tools for **relays, GPIO, sensors**; pattern mirrors the LED tool.

**Port to Ethernet boards:** Try a **W55RP20-EVB-Pico** (wired) variant to evaluate stability and latency on Ethernet vs. Wi-Fi.

**Operational demo:** Build a small **VPN-protected remote maintenance** scenario (agent ↔ field device) and document provisioning.

---

Source: https://maker.wiznet.io/matthew/projects/mcp-for-raspberry-pi-pico-w/