Cars MCP Server

This is an MCP (Model Context Protocol) server built using Spring AI. The project demonstrates the use of Spring AI's ToolCallback API to expose tools for interacting with a list of cars, which represents Amarpreet's wishlist.

Demo

Demo Video

Project Structure

The project is organized as follows:

• src/main/java/com/amarpreet/carsmcpserver/

  • CarsmcpserverApplication.java: The main entry point of the Spring Boot application. It initializes the application and registers the ToolCallback beans using the CarService class.
  • Car.java: A simple record class representing a car with two fields: modelName and buildYear.
  • CarService.java: A service class that provides methods to interact with the list of cars. These methods are exposed as tools using the ToolCallback API.

• src/main/resources/application.properties: Contains configuration properties for the Spring Boot application.

• src/test/java/com/amarpreet/carsmcpserver/

  • CarsmcpserverApplicationTests.java: Contains a basic test to ensure the application context loads correctly.

ToolCallback API

The ToolCallback API is used to expose methods from the CarService class as tools. These tools can be invoked programmatically or through an AI-driven interface. The CarsmcpserverApplication class registers these tools using the ToolCallbacks.from() method.

Tool Registration

In CarsmcpserverApplication.java:

@Bean
public List<ToolCallback> amarpreetTools(CarService carService) {
    return List.of(ToolCallbacks.from(carService));
}

This registers all methods annotated with @Tool in the CarService class as ToolCallback instances.

CarService

The CarService class is the core of this application. It manages a list of cars and provides the following methods:

Methods in CarService

getCars()

• Tool Name: get_cars
• Description: Retrieves the list of cars in Amarpreet's wishlist.
• Return Type: List<Car>

getCar(String name)

• Tool Name: get_car_by_name
• Description: Finds a car by its model name.
• Parameters:
  • name - The model name to search for.
• Return Type: Car (or null if not found)

getCarByYear(Integer year)

• Tool Name: get_car_by_years
• Description: Finds a car by its build year.
• Parameters:
  • year - The build year to search for.
• Return Type: Car (or null if not found)

Initialization

The CarService class initializes a list of cars during application startup using the @PostConstruct annotation:

public void init() {
    log.info("Initializing cars MCP server...");
    cars.addAll(List.of(
        new Car("BMW Neue Klasse", 2025),
        new Car("Ferrari EV", 2025),
        new Car("Mercedes AMG 4dr EV", 2025),
        new Car("Porsche 718 Boxster", 2025)
    ));
}

How to Run

Build the project using Maven:

mvn clean install

Run the application:

java -jar target/carsmcpserver-0.0.1-SNAPSHOT.jar

Configuration

The application can be configured using the application.properties file located in src/main/resources. Key properties include:

• spring.application.name: The name of the application.
• spring.main.web-application-type: Set to none for a non-web application.
• spring.ai.mcp.server: The name of the MCP server.
• spring.ai.mcp.version: The version of the MCP server.