Creating an MCP Server with Spring AI

<dependency>
  <groupId>org.springframework.ai</groupId>
  <artifactId>spring-ai-starter-mcp-server</artifactId>
</dependency>

public record Artist(String name) {
}

public record Song(Artist artist, String title) {
}

@Service
public class ArtistService {

    private final List<Artist> artists = new ArrayList<>();

    @Tool(name = "get_artists", description = "Get the complete list of Gunter's favorite artists")
    public List<Artist> getArtists() {
        return artists;
    }

    @PostConstruct
    public void init() {
        artists.addAll(List.of(
                new Artist("Bruce Springsteen"),
                new Artist("JJ Johnson")
        ));
    }

}

@Service
public class SongService {

    private final List<Song> songs = new ArrayList<>();

    @Tool(name = "get_songs", description = "Get the complete list of Gunter's favorite songs")
    public List<Song> getSongs() {
        return songs;
    }

    @PostConstruct
    public void init() {
        songs.addAll((List.of(
                new Song(new Artist("Bruce Springsteen"), "My Hometown"),
                new Song(new Artist("JJ Johnson"), "Lament")
        )));
    }

}

@SpringBootApplication
public class MyMcpServerPlanetApplication {

	public static void main(String[] args) {
		SpringApplication.run(MyMcpServerPlanetApplication.class, args);
	}

	@Bean
	public ToolCallbackProvider mcpServices(ArtistService artistService, SongService songService) {
		return MethodToolCallbackProvider.builder()
				.toolObjects(artistService,	songService)
				.build();
	}

}

spring.main.web-application-type=none
spring.ai.mcp.server.name=mcp-server
spring.ai.mcp.server.version=0.0.1

spring.main.banner-mode=off
logging.pattern.console=

mvn clean verify

2025-07-20 11:45:42 [DEBUG]
 Received request: POST to /v1/chat/completions with body  {
  "model": "qwen3-8b",
  "messages": [
    {
      "role": "system",
      "content": "You are a software developer IDEA plugin with expe... <Truncated in logs> ...at is correct and relevant to the code or plugin.\n"
    },
    {
      "role": "user",
      "content": "<ProjectPath>\n/home/<project directory>... <Truncated in logs> ... list of gunter's favorite artists\n</UserPrompt>\n\n"
    }
  ],
  "temperature": 0,
  "top_p": 0.9,
  "stream": false,
  "max_tokens": 8000,
  "tools": [
    {
      "type": "function",
      "function": {
        "name": "get_songs",
        "description": "Get the complete list of Gunter's favorite songs",
        "parameters": {
          "type": "object",
          "properties": {},
          "required": []
        }
      }
    },
    {
      "type": "function",
      "function": {
        "name": "get_artists",
        "description": "Get the complete list of Gunter's favorite artists",
        "parameters": {
          "type": "object",
          "properties": {},
          "required": []
        }
      }
    }
  ]
}

<think> Okay, the user asked for a list of Gunter's favorite artists. I called the \`get\_artists\` function and got back two artists: Bruce Springsteen and JJ Johnson. Now they might want to know if there are more or need further help.

I should confirm the results and maybe ask if there's anything else they need. Since the previous response was successful, it's good to keep that positive tone. No errors in the tool call, so no need for additional function calls here. </think>

Here are Gunter's favorite artists:

*   **Bruce Springsteen**
*   **JJ Johnson**

Let me know if you'd like more information or assistance!

<think> Okay, the user asked for a list of Gunter's favorite songs. I used the get\_songs function which retrieved two songs. Now I need to present this information clearly. Let me format each song with the artist and title. Make sure the response is easy to read, maybe bullet points. Check if there's any additional info needed, but since the user just wanted a list, keeping it simple should be best. </think>

Here is the list of Gunter's favorite songs:

1.  **Bruce Springsteen** - *My Hometown*
2.  **JJ Johnson** - *Lament*

Let me know if you'd like more details about any of these tracks!

@Tool(name = "search_artist", description = "Search a single artist from Gunter's favorite artists")
public Artist getArtist(String name) {
    return artists.stream()
            .filter(artist -> artist.name().equalsIgnoreCase(name))
            .findFirst()
            .orElse(null);
}

@Tool(name = "search_song", description = "Search a single song from Gunter's favorite songs")
public Song getSong(String title) {
    return songs.stream()
            .filter(song -> song.title().equalsIgnoreCase(title))
            .findFirst()
            .orElse(null);
}

<think> Okay, the user asked if Bruce Springsteen is one of Gunter's favorite artists. I used the search\_artist function with his name. The response came back with "Bruce Springsteen" as an artist. Now I need to check if he's in Gunter's favorites.

Wait, the functions available are get\_artists and search\_artist. The search\_artist function probably checks if the artist exists in the database. Since the response returned the artist, that means Bruce Springsteen is indeed in Gunter's favorite artists list.

So the answer should be yes. I should confirm that based on the function's response. No need for further actions since the user's question is answered. Just present the result clearly. </think>

Yes, Bruce Springsteen is one of Gunter's favorite artists. The search confirmed his presence in the collection.

<think> Okay, let me try to figure out what's going on here. The user asked if the Rolling Stones are one of Gunter's favorite artists. I used the search\_artist function with the name "Rolling Stones", but the response was null. That means the function didn't find any artist by that name in Gunter's favorites.

Hmm, maybe the artist's name isn't exactly "Rolling Stones" in the database. Could there be a typo or a different spelling? Or perhaps they're known by another name in the system. Alternatively, maybe the function isn't returning any results because the data isn't there.

Since the user is asking about Gunter's favorites, I should check if there's a way to list all favorite artists first. The get\_artists function could help here. If I call that, maybe I can see if the Rolling Stones are listed. But wait, the user might not want all artists, just confirmation on this specific one.

Alternatively, maybe the search\_artist function requires a different parameter. Let me check the tool definitions again. The search\_artist function takes a "name" parameter, which is required. So the query should be case-insensitive? Or maybe there's a partial match? The user might have meant "Rolling Stones" but the database has it stored differently.

Another thought: perhaps the Rolling Stones aren't in Gunter's favorite artists list. The search returned null, so maybe they aren't. But I should confirm by checking all artists first. Let me suggest that to the user. Wait, but the user is asking specifically about the Rolling Stones. Maybe I should inform them that the search didn't find any and ask if they want to check all artists instead.

Wait, the response was null, so the function didn't return any data. That means the artist isn't in the list. So the answer would be no, the Rolling Stones aren't one of Gunter's favorite artists. But maybe there's a mistake in the function call? Let me double-check. The function is called search\_artist with name "Rolling Stones". If the database has the exact name, then it should return. If not, then null.

So the conclusion is that the Rolling Stones aren't in Gunter's favorites. Alternatively, maybe there's a typo. But since the user is asking directly, I should answer based on the function's response. </think>

The search for the artist "Rolling Stones" did not return any results in Gunter's favorite artists list. This suggests that the Rolling Stones are **not** currently listed as one of Gunter's favorite artists. Would you like to check the full list of his favorite artists instead?