refactor: restructure MCP server auto-configuraitons, adding streamable-http support

- Extract MCP server functionality into specialized modules:
  * STDIO/SSE servers (existing functionality)
  * Streamable-HTTP servers with change notifications
  * Stateless servers for simplified deployments

- Add new auto-configuration modules:
  * spring-ai-autoconfigure-mcp-streamable-server-common
  * spring-ai-autoconfigure-mcp-streamable-server-webflux/webmvc
  * spring-ai-autoconfigure-mcp-stateless-server-common
  * spring-ai-autoconfigure-mcp-stateless-server-webflux/webmvc
  * Add server-specific property prefixes for different server types

- Extract ToolCallbackConverter into separate auto-configuration
  with conditional enablement via tool-callback-converter property

- Enhance transport providers with builder patterns and new features:
  * Keep-alive interval support for connection health
  * Add keep-alive-interval and other transport-specific options

- Add comprehensive integration tests for all server types

- Update documentation to reflect new architecture and server options

Signed-off-by: Christian Tzolov <[email protected]>

Author: tzolov

auto-configurations/mcp/spring-ai-autoconfigure-mcp-client-common/src/main/java/org/springframework/ai/mcp/client/common/autoconfigure/McpClientAutoConfiguration.java

@@ -104,8 +104,6 @@
 		"org.springframework.ai.mcp.client.httpclient.autoconfigure.StreamableHttpHttpClientTransportAutoConfiguration",
 		"org.springframework.ai.mcp.client.webflux.autoconfigure.SseWebFluxTransportAutoConfiguration",
 		"org.springframework.ai.mcp.client.webflux.autoconfigure.StreamableHttpWebFluxTransportAutoConfiguration" })
-
-// @AutoConfiguration
 @ConditionalOnClass({ McpSchema.class })
 @EnableConfigurationProperties(McpClientCommonProperties.class)
 @ConditionalOnProperty(prefix = McpClientCommonProperties.CONFIG_PREFIX, name = "enabled", havingValue = "true",

auto-configurations/mcp/spring-ai-autoconfigure-mcp-client-common/src/main/java/org/springframework/ai/mcp/client/common/autoconfigure/properties/McpStreamableHttpClientProperties.java

@@ -31,7 +31,7 @@
  * <p>
  * Example configuration: <pre>
  * spring.ai.mcp.client.streamable-http:
- *   connections-http:
+ *   connections:
  *     server1:
  *       url: http://localhost:8080/events
  *     server2:

auto-configurations/mcp/spring-ai-autoconfigure-mcp-server/pom.xml

@@ -68,6 +68,25 @@
 			<scope>test</scope>
 		</dependency>
 
+		<dependency>
+			<groupId>net.javacrumbs.json-unit</groupId>
+			<artifactId>json-unit-assertj</artifactId>
+			<version>${json-unit-assertj.version}</version>
+			<scope>test</scope>
+		</dependency>
+
+		<dependency>
+			<groupId>org.springframework.ai</groupId>
+			<artifactId>spring-ai-autoconfigure-mcp-client-webflux</artifactId>
+			<version>${project.parent.version}</version>
+			<scope>test</scope>
+		</dependency>
+
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-webflux</artifactId>
+			<scope>test</scope>
+		</dependency>
 
 	</dependencies>
 

auto-configurations/mcp/spring-ai-autoconfigure-mcp-server/src/main/java/org/springframework/ai/mcp/server/autoconfigure/McpServerAutoConfiguration.java

@@ -20,14 +20,26 @@
 import java.util.List;
 import java.util.function.BiConsumer;
 import java.util.function.BiFunction;
-import java.util.stream.Collectors;
+
+import org.springframework.ai.tool.ToolCallback;
+import org.springframework.beans.factory.ObjectProvider;
+import org.springframework.boot.autoconfigure.AutoConfiguration;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.context.annotation.Bean;
+import org.springframework.core.env.Environment;
+import org.springframework.core.log.LogAccessor;
+import org.springframework.util.CollectionUtils;
+import org.springframework.web.context.support.StandardServletEnvironment;
 
 import io.modelcontextprotocol.server.McpAsyncServer;
 import io.modelcontextprotocol.server.McpAsyncServerExchange;
 import io.modelcontextprotocol.server.McpServer;
 import io.modelcontextprotocol.server.McpServer.AsyncSpecification;
 import io.modelcontextprotocol.server.McpServer.SyncSpecification;
-import io.modelcontextprotocol.server.McpServerFeatures;
 import io.modelcontextprotocol.server.McpServerFeatures.AsyncCompletionSpecification;
 import io.modelcontextprotocol.server.McpServerFeatures.AsyncPromptSpecification;
 import io.modelcontextprotocol.server.McpServerFeatures.AsyncResourceSpecification;
@@ -44,23 +56,6 @@
 import io.modelcontextprotocol.spec.McpServerTransportProvider;
 import reactor.core.publisher.Mono;
 
-import org.springframework.ai.mcp.McpToolUtils;
-import org.springframework.ai.tool.ToolCallback;
-import org.springframework.ai.tool.ToolCallbackProvider;
-import org.springframework.beans.factory.ObjectProvider;
-import org.springframework.boot.autoconfigure.AutoConfiguration;
-import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
-import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
-import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
-import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
-import org.springframework.boot.context.properties.EnableConfigurationProperties;
-import org.springframework.context.annotation.Bean;
-import org.springframework.core.env.Environment;
-import org.springframework.core.log.LogAccessor;
-import org.springframework.util.CollectionUtils;
-import org.springframework.util.MimeType;
-import org.springframework.web.context.support.StandardServletEnvironment;
-
 /**
  * {@link EnableAutoConfiguration Auto-configuration} for the Model Context Protocol (MCP)
  * Server.
@@ -110,7 +105,8 @@
  * @see McpWebFluxServerAutoConfiguration
  * @see ToolCallback
  */
-@AutoConfiguration(after = { McpWebMvcServerAutoConfiguration.class, McpWebFluxServerAutoConfiguration.class })
+@AutoConfiguration(after = { ToolCallbackConverterAutoConfiguration.class, McpWebMvcServerAutoConfiguration.class,
+		McpWebFluxServerAutoConfiguration.class })
 @ConditionalOnClass({ McpSchema.class, McpSyncServer.class })
 @EnableConfigurationProperties(McpServerProperties.class)
 @ConditionalOnProperty(prefix = McpServerProperties.CONFIG_PREFIX, name = "enabled", havingValue = "true",
@@ -131,44 +127,6 @@ public McpSchema.ServerCapabilities.Builder capabilitiesBuilder() {
 		return McpSchema.ServerCapabilities.builder();
 	}
 
-	@Bean
-	@ConditionalOnProperty(prefix = McpServerProperties.CONFIG_PREFIX, name = "type", havingValue = "SYNC",
-			matchIfMissing = true)
-	public List<McpServerFeatures.SyncToolSpecification> syncTools(ObjectProvider<List<ToolCallback>> toolCalls,
-			List<ToolCallback> toolCallbacksList, McpServerProperties serverProperties) {
-
-		List<ToolCallback> tools = new ArrayList<>(toolCalls.stream().flatMap(List::stream).toList());
-
-		if (!CollectionUtils.isEmpty(toolCallbacksList)) {
-			tools.addAll(toolCallbacksList);
-		}
-
-		return this.toSyncToolSpecifications(tools, serverProperties);
-	}
-
-	private List<McpServerFeatures.SyncToolSpecification> toSyncToolSpecifications(List<ToolCallback> tools,
-			McpServerProperties serverProperties) {
-
-		// De-duplicate tools by their name, keeping the first occurrence of each tool
-		// name
-		return tools.stream() // Key: tool name
-			.collect(Collectors.toMap(tool -> tool.getToolDefinition().name(), tool -> tool, // Value:
-																								// the
-																								// tool
-																								// itself
-					(existing, replacement) -> existing)) // On duplicate key, keep the
-															// existing tool
-			.values()
-			.stream()
-			.map(tool -> {
-				String toolName = tool.getToolDefinition().name();
-				MimeType mimeType = (serverProperties.getToolResponseMimeType().containsKey(toolName))
-						? MimeType.valueOf(serverProperties.getToolResponseMimeType().get(toolName)) : null;
-				return McpToolUtils.toSyncToolSpecification(tool, mimeType);
-			})
-			.toList();
-	}
-
 	@Bean
 	@ConditionalOnProperty(prefix = McpServerProperties.CONFIG_PREFIX, name = "type", havingValue = "SYNC",
 			matchIfMissing = true)
@@ -179,7 +137,7 @@ public McpSyncServer mcpSyncServer(McpServerTransportProvider transportProvider,
 			ObjectProvider<List<SyncPromptSpecification>> prompts,
 			ObjectProvider<List<SyncCompletionSpecification>> completions,
 			ObjectProvider<BiConsumer<McpSyncServerExchange, List<McpSchema.Root>>> rootsChangeConsumers,
-			List<ToolCallbackProvider> toolCallbackProvider, Environment environment) {
+			Environment environment) {
 
 		McpSchema.Implementation serverInfo = new Implementation(serverProperties.getName(),
 				serverProperties.getVersion());
@@ -195,15 +153,6 @@ public McpSyncServer mcpSyncServer(McpServerTransportProvider transportProvider,
 			List<SyncToolSpecification> toolSpecifications = new ArrayList<>(
 					tools.stream().flatMap(List::stream).toList());
 
-			List<ToolCallback> providerToolCallbacks = toolCallbackProvider.stream()
-				.map(pr -> List.of(pr.getToolCallbacks()))
-				.flatMap(List::stream)
-				.filter(fc -> fc instanceof ToolCallback)
-				.map(fc -> (ToolCallback) fc)
-				.toList();
-
-			toolSpecifications.addAll(this.toSyncToolSpecifications(providerToolCallbacks, serverProperties));
-
 			if (!CollectionUtils.isEmpty(toolSpecifications)) {
 				serverBuilder.tools(toolSpecifications);
 				logger.info("Registered tools: " + toolSpecifications.size());
@@ -268,41 +217,6 @@ public McpSyncServer mcpSyncServer(McpServerTransportProvider transportProvider,
 		return serverBuilder.build();
 	}
 
-	@Bean
-	@ConditionalOnProperty(prefix = McpServerProperties.CONFIG_PREFIX, name = "type", havingValue = "ASYNC")
-	public List<McpServerFeatures.AsyncToolSpecification> asyncTools(ObjectProvider<List<ToolCallback>> toolCalls,
-			List<ToolCallback> toolCallbackList, McpServerProperties serverProperties) {
-
-		List<ToolCallback> tools = new ArrayList<>(toolCalls.stream().flatMap(List::stream).toList());
-		if (!CollectionUtils.isEmpty(toolCallbackList)) {
-			tools.addAll(toolCallbackList);
-		}
-
-		return this.toAsyncToolSpecification(tools, serverProperties);
-	}
-
-	private List<McpServerFeatures.AsyncToolSpecification> toAsyncToolSpecification(List<ToolCallback> tools,
-			McpServerProperties serverProperties) {
-		// De-duplicate tools by their name, keeping the first occurrence of each tool
-		// name
-		return tools.stream() // Key: tool name
-			.collect(Collectors.toMap(tool -> tool.getToolDefinition().name(), tool -> tool, // Value:
-																								// the
-																								// tool
-																								// itself
-					(existing, replacement) -> existing)) // On duplicate key, keep the
-															// existing tool
-			.values()
-			.stream()
-			.map(tool -> {
-				String toolName = tool.getToolDefinition().name();
-				MimeType mimeType = (serverProperties.getToolResponseMimeType().containsKey(toolName))
-						? MimeType.valueOf(serverProperties.getToolResponseMimeType().get(toolName)) : null;
-				return McpToolUtils.toAsyncToolSpecification(tool, mimeType);
-			})
-			.toList();
-	}
-
 	@Bean
 	@ConditionalOnProperty(prefix = McpServerProperties.CONFIG_PREFIX, name = "type", havingValue = "ASYNC")
 	public McpAsyncServer mcpAsyncServer(McpServerTransportProvider transportProvider,
@@ -311,8 +225,7 @@ public McpAsyncServer mcpAsyncServer(McpServerTransportProvider transportProvide
 			ObjectProvider<List<AsyncResourceSpecification>> resources,
 			ObjectProvider<List<AsyncPromptSpecification>> prompts,
 			ObjectProvider<List<AsyncCompletionSpecification>> completions,
-			ObjectProvider<BiConsumer<McpAsyncServerExchange, List<McpSchema.Root>>> rootsChangeConsumer,
-			List<ToolCallbackProvider> toolCallbackProvider) {
+			ObjectProvider<BiConsumer<McpAsyncServerExchange, List<McpSchema.Root>>> rootsChangeConsumer) {
 
 		McpSchema.Implementation serverInfo = new Implementation(serverProperties.getName(),
 				serverProperties.getVersion());
@@ -324,14 +237,6 @@ public McpAsyncServer mcpAsyncServer(McpServerTransportProvider transportProvide
 		if (serverProperties.getCapabilities().isTool()) {
 			List<AsyncToolSpecification> toolSpecifications = new ArrayList<>(
 					tools.stream().flatMap(List::stream).toList());
-			List<ToolCallback> providerToolCallbacks = toolCallbackProvider.stream()
-				.map(pr -> List.of(pr.getToolCallbacks()))
-				.flatMap(List::stream)
-				.filter(fc -> fc instanceof ToolCallback)
-				.map(fc -> (ToolCallback) fc)
-				.toList();
-
-			toolSpecifications.addAll(this.toAsyncToolSpecification(providerToolCallbacks, serverProperties));
 
 			logger.info("Enable tools capabilities, notification: " + serverProperties.isToolChangeNotification());
 			capabilitiesBuilder.tools(serverProperties.isToolChangeNotification());

auto-configurations/mcp/spring-ai-autoconfigure-mcp-server/src/main/java/org/springframework/ai/mcp/server/autoconfigure/McpServerProperties.java

@@ -140,6 +140,11 @@ public class McpServerProperties {
 	 */
 	private Duration requestTimeout = Duration.ofSeconds(20);
 
+	/**
+	 * The duration to keep the connection alive. Disabled by default.
+	 */
+	private Duration keepAliveInterval;
+
 	public Duration getRequestTimeout() {
 		return this.requestTimeout;
 	}
@@ -281,6 +286,14 @@ public Map<String, String> getToolResponseMimeType() {
 		return this.toolResponseMimeType;
 	}
 
+	public void setKeepAliveInterval(Duration keepAliveInterval) {
+		this.keepAliveInterval = keepAliveInterval;
+	}
+
+	public Duration getKeepAliveInterval() {
+		return this.keepAliveInterval;
+	}
+
 	public static class Capabilities {
 
 		private boolean resource = true;

auto-configurations/mcp/spring-ai-autoconfigure-mcp-server/src/main/java/org/springframework/ai/mcp/server/autoconfigure/McpWebFluxServerAutoConfiguration.java

@@ -49,7 +49,9 @@
  * <li>A RouterFunction bean that sets up the reactive SSE endpoint</li>
  * </ul>
  * <p>
- * Required dependencies: <pre>{@code
+ * Required dependencies:
+ *
+ * <pre>{@code
  * <dependency>
  *     <groupId>io.modelcontextprotocol.sdk</groupId>
  *     <artifactId>mcp-spring-webflux</artifactId>
@@ -76,12 +78,20 @@ public class McpWebFluxServerAutoConfiguration {
 	@ConditionalOnMissingBean
 	public WebFluxSseServerTransportProvider webFluxTransport(ObjectProvider<ObjectMapper> objectMapperProvider,
 			McpServerProperties serverProperties) {
+
 		ObjectMapper objectMapper = objectMapperProvider.getIfAvailable(ObjectMapper::new);
-		return new WebFluxSseServerTransportProvider(objectMapper, serverProperties.getBaseUrl(),
-				serverProperties.getSseMessageEndpoint(), serverProperties.getSseEndpoint());
+
+		return WebFluxSseServerTransportProvider.builder()
+			.objectMapper(objectMapper)
+			.basePath(serverProperties.getBaseUrl())
+			.messageEndpoint(serverProperties.getSseMessageEndpoint())
+			.sseEndpoint(serverProperties.getSseEndpoint())
+			.keepAliveInterval(serverProperties.getKeepAliveInterval())
+			.build();
 	}
 
-	// Router function for SSE transport used by Spring WebFlux to start an HTTP server.
+	// Router function for SSE transport used by Spring WebFlux to start an HTTP
+	// server.
 	@Bean
 	public RouterFunction<?> webfluxMcpRouterFunction(WebFluxSseServerTransportProvider webFluxProvider) {
 		return webFluxProvider.getRouterFunction();

auto-configurations/mcp/spring-ai-autoconfigure-mcp-server/src/main/java/org/springframework/ai/mcp/server/autoconfigure/McpWebMvcServerAutoConfiguration.java

@@ -71,9 +71,16 @@ public class McpWebMvcServerAutoConfiguration {
 	@ConditionalOnMissingBean
 	public WebMvcSseServerTransportProvider webMvcSseServerTransportProvider(
 			ObjectProvider<ObjectMapper> objectMapperProvider, McpServerProperties serverProperties) {
+
 		ObjectMapper objectMapper = objectMapperProvider.getIfAvailable(ObjectMapper::new);
-		return new WebMvcSseServerTransportProvider(objectMapper, serverProperties.getBaseUrl(),
-				serverProperties.getSseMessageEndpoint(), serverProperties.getSseEndpoint());
+
+		return WebMvcSseServerTransportProvider.builder()
+			.objectMapper(objectMapper)
+			.baseUrl(serverProperties.getBaseUrl())
+			.sseEndpoint(serverProperties.getSseEndpoint())
+			.messageEndpoint(serverProperties.getSseMessageEndpoint())
+			.keepAliveInterval(serverProperties.getKeepAliveInterval())
+			.build();
 	}
 
 	@Bean