Spring AI with 1.1.0-snapshot and 1.1.0-M1 can't call the mcp server by SSE in the starter-webmvc-server status: 404, error: Not Found

Bug description Cant access the mcp server by http://localhost:port/sse with 1.1.0-snapshot or 1.1.0-M1

When I pull the project and open the module starter-webmvc-server. The default version is here:

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.ai</groupId>
                <artifactId>spring-ai-bom</artifactId>
                <version>1.1.0-SNAPSHOT</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

I want to run the module starter-webmvc-server here is the application.properties

# spring.main.web-application-type=none

# NOTE: You must disable the banner and the console logging 
# to allow the STDIO transport to work !!!
server.port=9090
spring.main.banner-mode=off
# logging.pattern.console=

spring.ai.mcp.server.stdio=false
spring.ai.mcp.server.enabled=true

spring.ai.mcp.server.name=my-weather-server
spring.ai.mcp.server.version=0.0.1
spring.ai.mcp.server.sse-message-endpoint=/mcp/messages

spring.ai.mcp.server.protocol=STREAMABLE
# spring.ai.mcp.server.protocol=STATELESS

logging.file.name=./model-context-protocol/weather/starter-webmvc-server/target/starter-webmvc-server.log

The server can start however the connection is always failed with http://localhost:port/sse

% curl -v -N  http://localhost:9090/sse
* Host localhost:9090 was resolved.
* IPv6: ::1
* IPv4: 127.0.0.1
*   Trying [::1]:9090...
* Connected to localhost (::1) port 9090
> GET /sse HTTP/1.1
> Host: localhost:9090
> User-Agent: curl/8.7.1
> Accept: */*
> 
* Request completely sent off
< HTTP/1.1 404 
< Vary: Origin
< Vary: Access-Control-Request-Method
< Vary: Access-Control-Request-Headers
< Content-Type: application/json
< Transfer-Encoding: chunked
< Date: Tue, 23 Sep 2025 03:42:28 GMT
< 
{"timestamp":"2025-09-23T03:42:28.228+00:00","status":404,"error":"Not Found","path":"/sse"}* Connection #0 to host localhost left intact

Environment in my localhost

Steps to reproduce Download the project and run it.

Expected behavior The sse could work

Minimal Complete Reproducible example I also test 1.1.0-M1 it doesn't wok.

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.ai</groupId>
                <artifactId>spring-ai-bom</artifactId>
                <version>1.1.0-M1</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

However When I change the version to 1.0.2 It works.

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.ai</groupId>
                <artifactId>spring-ai-bom</artifactId>
                <version>1.0.2</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

I want to use the HttpClientStreamableHttpTransport in 1.1.0-X. So how could I run the project with 1.1.0-snapshot

Many thanks in advance

Comment From: YunKuiLu

The configuration related to SSE is spring.ai.mcp.server.protocol=SSE. Can you modify the application.properties and try again?