Issue 4055

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

@@ -55,6 +55,7 @@
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Lazy;
 import org.springframework.core.log.LogAccessor;
 import org.springframework.util.CollectionUtils;
 import org.springframework.util.MimeType;
@@ -168,6 +169,7 @@ private List<McpServerFeatures.SyncToolSpecification> toSyncToolSpecifications(L
 	}
 
 	@Bean
+	@Lazy(false)
 	@ConditionalOnProperty(prefix = McpServerProperties.CONFIG_PREFIX, name = "type", havingValue = "SYNC",
 			matchIfMissing = true)
 	public McpSyncServer mcpSyncServer(McpServerTransportProvider transportProvider,
@@ -299,6 +301,7 @@ private List<McpServerFeatures.AsyncToolSpecification> toAsyncToolSpecification(
 	}
 
 	@Bean
+	@Lazy(false)
 	@ConditionalOnProperty(prefix = McpServerProperties.CONFIG_PREFIX, name = "type", havingValue = "ASYNC")
 	public McpAsyncServer mcpAsyncServer(McpServerTransportProvider transportProvider,
 			McpSchema.ServerCapabilities.Builder capabilitiesBuilder, McpServerProperties serverProperties,

auto-configurations/mcp/spring-ai-autoconfigure-mcp-server/src/test/java/org/springframework/ai/mcp/server/autoconfigure/McpServerAutoConfigurationIT.java

@@ -490,6 +490,40 @@ public Mono<Void> closeGracefully() {
 
 	}
 
+	@Test
+	void lazyInitializationConfiguration() {
+		this.contextRunner.withPropertyValues("spring.main.lazy-initialization=true").run(context -> {
+			// With lazy initialization enabled, MCP servers should still be created due
+			// to @Lazy(false)
+			assertThat(context).hasSingleBean(McpSyncServer.class);
+			assertThat(context).doesNotHaveBean(McpAsyncServer.class);
+
+			// Verify properties are properly configured even with lazy init
+			McpServerProperties properties = context.getBean(McpServerProperties.class);
+			assertThat(properties.getName()).isEqualTo("mcp-server");
+			assertThat(properties.getType()).isEqualTo(McpServerProperties.ServerType.SYNC);
+
+			// Verify server is properly initialized (not just created)
+			McpSyncServer server = context.getBean(McpSyncServer.class);
+			assertThat(server).isNotNull();
+		});
+	}
+
+	@Test
+	void asyncServerLazyInitializationConfiguration() {
+		this.contextRunner.withPropertyValues("spring.main.lazy-initialization=true", "spring.ai.mcp.server.type=ASYNC")
+			.run(context -> {
+				// With lazy initialization enabled, async MCP server should still be
+				// created due to @Lazy(false)
+				assertThat(context).hasSingleBean(McpAsyncServer.class);
+				assertThat(context).doesNotHaveBean(McpSyncServer.class);
+
+				// Verify server is properly initialized (not just created)
+				McpAsyncServer server = context.getBean(McpAsyncServer.class);
+				assertThat(server).isNotNull();
+			});
+	}
+
 	@Configuration
 	static class CustomTransportConfiguration {
 

auto-configurations/mcp/spring-ai-autoconfigure-mcp-server/src/test/java/org/springframework/ai/mcp/server/autoconfigure/McpWebMvcServerAutoConfigurationIT.java

@@ -68,4 +68,21 @@ void serverBaseUrlConfiguration() {
 				.isEqualTo("/test"));
 	}
 
+	@Test
+	void lazyInitializationWithWebMvcCompatibility() {
+		this.contextRunner.withPropertyValues("spring.main.lazy-initialization=true").run(context -> {
+			// Even with lazy initialization, WebMvc transport should work properly
+			assertThat(context).hasSingleBean(WebMvcSseServerTransportProvider.class);
+			assertThat(context).hasSingleBean(RouterFunction.class);
+
+			// Transport provider should be properly configured
+			WebMvcSseServerTransportProvider transport = context.getBean(WebMvcSseServerTransportProvider.class);
+			assertThat(transport).isNotNull();
+
+			// Router function should be available
+			RouterFunction<?> routerFunction = context.getBean(RouterFunction.class);
+			assertThat(routerFunction).isNotNull();
+		});
+	}
+
 }