java-sdk/mcp-docs/0.5.0-BREAKING-CHANGES.md

Breaking Changes for Spring AI MCP 0.5.0-SNAPSHOT

Major Changes

1. Transport Implementation Modularization

   • SSE transport implementations have been moved to dedicated modules:
     • mcp-webflux-sse-transport: WebFlux-based SSE transport
     • mcp-webmvc-sse-transport: WebMVC-based SSE transport
   • Base MCP module no longer includes transport implementations

2. Class Renames

   • SseClientTransport → WebFluxSseClientTransport
   • SseServerTransport → WebFluxSseServerTransport

3. Project Structure

   • Test utilities moved to new mcp-test module
   • All samples moved to the the https://github.com/spring-projects/spring-ai-examples/tree/main/model-context-protocol

Migration Guide

1. Update Dependencies

If using SSE transport, add the appropriate transport module to your pom.xml:

For WebFlux SSE transport:

<dependency>
    <groupId>org.springframework.experimental</groupId>
    <artifactId>mcp-webflux-sse-transport</artifactId>
    <version>0.5.0-SNAPSHOT</version>
</dependency>

For WebMVC SSE transport:

<dependency>
    <groupId>org.springframework.experimental</groupId>
    <artifactId>mcp-webmvc-sse-transport</artifactId>
    <version>0.5.0-SNAPSHOT</version>
</dependency>

2. Update Transport Class References

Replace:

import org.springframework.ai.mcp.client.transport.SseClientTransport;
import org.springframework.ai.mcp.server.transport.SseServerTransport;

With:

// For WebFlux
import org.springframework.ai.mcp.client.transport.WebFluxSseClientTransport;
import org.springframework.ai.mcp.server.transport.WebFluxSseServerTransport;

// Or for WebMVC
import org.springframework.ai.mcp.server.transport.WebMvcSseServerTransport;

3. Update Transport Instantiation

Replace:

var transport = new SseClientTransport(webClientBuilder);

With:

var transport = new WebFluxSseClientTransport(webClientBuilder);

Replace:

var serverTransport = new SseServerTransport(objectMapper, messageEndpoint);

With:

// For WebFlux
var serverTransport = new WebFluxSseServerTransport(objectMapper, messageEndpoint);

// Or for WebMVC
var serverTransport = new WebMvcSseServerTransport(objectMapper, messageEndpoint);

4. Test Dependencies

If you're using MCP test utilities, add the test module dependency:

<dependency>
    <groupId>org.springframework.experimental</groupId>
    <artifactId>mcp-test</artifactId>
    <version>0.5.0-SNAPSHOT</version>
    <scope>test</scope>
</dependency>

Other Changes

• Spring AI dependency updated to 1.0.0-M5
• Improved dependency management and reduced transitive dependencies
• Sample application restructured under samples/ directory
• New test utilities and base test classes in mcp-test module