Xiaozhi MCP Client (小智 MCP 客户端)

Introduction

Mind+ upload mode extension that enables boards to act as an MCP (Model Context Protocol) client for the Xiaozhi AI service. It connects via WebSocket and supports registering sensor tools that Xiaozhi can call.

• Extension ID: xiaozhimcp
• Version: 0.0.2
• Author: Nick
• Mode: Upload Mode (upload)

Version History

Compatible Hardware

This extension requires a WiFi network connection to connect to the MCP server.

Feature Overview

Provides the following block capabilities for WebSocket MCP communication:

Dependencies

This extension depends on the following Arduino libraries:

• WiFi: WiFi connection
• WebSocketMCP: WebSocket client for MCP protocol
• ArduinoJson: JSON parsing and serialization library

Block Description

Initialization

Initialize WiFi SSID [SSID] Password [PASSWORD]

Configure and maintain a WiFi connection. Automatically attempts to reconnect if the connection drops.

• SSID: The name of the WiFi network
• PASSWORD: The WiFi password

Initialize MCP Connection Endpoint [ENDPOINT]

Set up the WebSocket connection to the MCP server. Automatically registers all tools once connected.

• ENDPOINT: The WebSocket URL for the MCP server (e.g., wss://api.xiaozhi.me/mcp/?token=your_token)

Main Loop

Maintain MCP Connection

Must be placed in the main execution sequence to keep the WebSocket connection alive and process incoming messages. It also continuously checks the WiFi status.

Tool Registration & Handling

Add Parameter [PARAM_NAME] Title[PARAM_TITLE] Type[PARAM_TYPE] Desc[PARAM_DESC]

Declares a parameter for the next Register Tool block. Place one or more of these blocks immediately before Register Tool. The parameter information is used to build the JSON Schema that tells the AI what arguments to provide.

• PARAM_NAME: The parameter key name (used in code to read the value)
• PARAM_TITLE: A human-readable title for the parameter
• PARAM_TYPE: The data type — string, number, or boolean
• PARAM_DESC: A description of what the parameter means

Set Last Param Choices [CHOICES]

Sets an enum (allowed values list) on the most recently declared parameter. Place immediately after Add Parameter.

• CHOICES: Comma-separated list of allowed values (e.g., on,off,blink,flow)

Register Tool [TOOL_NAME] Description [DESCRIPTION]

Registers a new tool that the AI can call. Place after all Add Parameter blocks for this tool.

• TOOL_NAME: The identifier for the tool
• DESCRIPTION: A description of what the tool does (helps the AI understand when to call it)

When MCP receives tool call [TOOL_NAME]

An event block (Hat block) that triggers when the AI decides to use the registered tool.

• TOOL_NAME: The identifier for the tool being called

Get MCP string param [KEY]

Reporter block. Returns the string value of a named argument passed by the AI in the current tool call.

• KEY: The parameter name to read

Get MCP number param [KEY]

Reporter block. Returns the numeric (float) value of a named argument passed by the AI.

• KEY: The parameter name to read

Get MCP boolean param [KEY]

Boolean block. Returns true/false for a named argument passed by the AI.

• KEY: The parameter name to read

Return MCP result [KEY] : [VALUE]

Sends data back to the AI after a tool has been executed. This must be used inside the "When MCP receives tool call" block.

• KEY: The JSON key for the return data
• VALUE: The corresponding value to return

Usage Example

Add Parameter "state"  Title["LED状态"] Type[string]  Desc["LED mode"]
Set Last Param Choices "on,off,blink,flow"
Register Tool "led_control"  Description[...]

When MCP receives tool call "led_control"
  → if (Get MCP string param "state") == "on"  →  turn on LED
  → Return MCP result "result" : "done"