api2mcp4j

Zero-to-low code MCP integration for your Spring Boot REST APIs
Turn your existing Spring Boot controllers into an MCP (Model Context Protocol) server in minutes — no @Tool annotations everywhere, no rewriting business logic.

✨ Why api2mcp4j?

Most MCP integrations require you to:
- Add @Tool / @McpTool annotations to every method
- Duplicate or heavily refactor code
- Maintain separate tool descriptions

api2mcp4j changes that.

It automatically scans your existing @RestController / @Service beans and exposes them as MCP tools with minimal configuration — leveraging parsers from:

- Swagger/OpenAPI (v2 & v3)
- Javadoc
- Spring MVC metadata
- Jackson
- Spring AI native descriptions
- Custom @Tool / @McpTool (optional)

Result: Your current REST APIs become AI-callable tools almost for free.

🔥 Key Features

- Non-intrusive — No need to change business code (like MyBatis-Plus enhances MyBatis)
- Auto-discovery — Scans controllers/services and registers methods as MCP tools
- Multi-parser support — Smartly combines descriptions & parameter info from Swagger, Javadoc, etc.
- Custom annotations — @ToolScan, @ResourceScan, @PromptScan for fine-grained control
- Isolated MCP tool system — Uses McpTool annotation (independent of Spring AI @Tool)
- Full MCP SDK compatibility — Supports latest MCP Java SDK features (callbacks, resources, prompts)
- Easy debugging — Works great with Cursor, Continue, or any MCP client

Quick Start (≈ 5 minutes)

1. Add dependency

> Note: Project not yet in Maven Central — build from source for now.

# Clone & build
git clone https://github.com/TheEterna/api2mcp4j.git
cd api2mcp4j/server2mcp-starter-webmvc
mvn clean install

<!-- pom.xml -->
<dependency>
    <groupId>com.ai.plug</groupId>
    <artifactId>server2mcp-starter-webmvc</artifactId>
    <version>1.1.4-SNAPSHOT</version> <!-- or latest after build -->
</dependency>

2. Enable in application.yml

plugin:
  mcp:
    enabled: true
    # Recommended: use multiple parsers for best description quality
    parser:
      params: SWAGGER3, SWAGGER2, SpringMVC, JACKSON, TOOL  # JAVADOC needs extra setup
      des:    SWAGGER3, SWAGGER2, JAVADOC, TOOL, JACKSON
    # 'interface' = auto-register all controller methods (skip @Deprecated)
    # 'custom'   = only register via @ToolScan / manual
    scope: interface

3. (Optional) Javadoc parser setup

To enable Javadoc parsing in production (bytecode doesn't contain comments):

<!-- pom.xml - package sources -->
<plugin>
    <groupId>org.apache.maven.plugins</groupId>
    <artifactId>maven-resources-plugin</artifactId>
    <executions>
        <execution>
            <id>copy-java-sources</id>
            <phase>prepare-package</phase>
            <goals><goal>copy-resources</goal></goals>
            <configuration>
                <outputDirectory>${project.build.outputDirectory}</outputDirectory>
                <resources>
                    <resource>
                        <directory>src/main/java</directory>
                        <includes><include>/.java</include></includes>
                    </resource>
                </resources>
            </configuration>
        </execution>
    </executions>
</plugin>

作者的话**
这是一个我投入大量心血的个人项目，希望能真正帮助到更多 Spring Boot 开发者快速拥抱 MCP/AI Agent 时代。感谢每一位 star 和使用它的人！
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- 语言更流畅、专业、吸引人

你可以直接发给作者，建议他 review 后合并（或作为 PR）。如果需要，我可以再调整语气、加 GIF/demo 图位置提示，或写中文版。