docs(security): allow /v3/api-docs(.yaml) & Swagger UI when Spring Security is enabled (management port)

README.md

@@ -56,6 +56,8 @@ This project is sponsored by
     - [Error Handling for REST using @ControllerAdvice](#error-handling-for-rest-using-controlleradvice)
     - [Adding API Information and Security documentation](#adding-api-information-and-security-documentation)
     - [spring-webflux support with Annotated Controllers](#spring-webflux-support-with-annotated-controllers)
+    - [Using a separate management port (Spring Boot 3)](#using-a-separate-management-port-spring-boot-3)
+    - [When Spring Security is enabled](#when-spring-security-is-enabled)
 - [Acknowledgements](#acknowledgements)
     - [Contributors](#contributors)
     - [Additional Support](#additional-support)
@@ -253,6 +255,59 @@ Snapshots:
 * [https://central.sonatype.com/service/rest/repository/browse/maven-snapshots/org/springdoc/](https://central.sonatype.com/service/rest/repository/browse/maven-snapshots/org/springdoc/)
   .
 
+## Using a separate management port (Spring Boot 3)
+
+Some Spring Boot apps run **Actuator** on a separate management port. In that case:
+
+- **Application port** (e.g., `8080`) serves your app and springdoc endpoints:
+  - `http://localhost:8080/v3/api-docs`
+  - `http://localhost:8080/swagger-ui/index.html`
+
+- **Management port** (e.g., `9090`) serves Actuator:
+  - `http://localhost:9090/actuator`
+  - `http://localhost:9090/actuator/health`
+
+Minimal `application.yml`:
+
+```yaml
+server:
+  port: 8080
+
+management:
+  server:
+    port: 9090
+  endpoints:
+    web:
+      exposure:
+        include: health,info
+
+# springdoc is enabled by default with the starter;
+# endpoints remain on the application port.
+# (OpenAPI JSON = /v3/api-docs, Swagger UI = /swagger-ui/index.html)
+```
+
+### When Spring Security is enabled
+
+With Spring Boot 3, `/v3/api-docs` and Swagger UI are served on the **application port**, while Actuator runs on the **management port**.  
+If Spring Security is enabled, explicitly permit the docs paths on the **application port**:
+
+```java
+@Bean
+SecurityFilterChain api(HttpSecurity http) throws Exception {
+  http
+    .authorizeHttpRequests(auth -> auth
+      .requestMatchers(
+        "/v3/api-docs/**",   
+        "/v3/api-docs.yaml", 
+        "/swagger-ui/**",
+        "/swagger-ui.html"
+      ).permitAll()
+      .anyRequest().authenticated()
+    );
+  return http.build();
+}
+```
+
 # Acknowledgements
 
 ## Contributors