diff --git a/rustfs/src/admin/route_registration_test.rs b/rustfs/src/admin/route_registration_test.rs
index fc3566f5..ee2fc485 100644
--- a/rustfs/src/admin/route_registration_test.rs
+++ b/rustfs/src/admin/route_registration_test.rs
@@ -15,6 +15,7 @@
 use crate::admin::{
     handlers::{bucket_meta, heal, health, kms, pools, profile_admin, quota, rebalance, replication, sts, system, tier, user},
     router::{AdminOperation, S3Router},
+    rpc,
 };
 use crate::server::{ADMIN_PREFIX, HEALTH_PREFIX, HEALTH_READY_PATH, PROFILE_CPU_PATH, PROFILE_MEMORY_PATH};
 use hyper::Method;
@@ -49,6 +50,7 @@ fn test_register_routes_cover_representative_admin_paths() {
     replication::register_replication_route(&mut router).expect("register replication route");
     profile_admin::register_profiling_route(&mut router).expect("register profile route");
     kms::register_kms_route(&mut router).expect("register kms route");
+    rpc::register_rpc_route(&mut router).expect("register rpc route");
 
     assert_route(&router, Method::GET, HEALTH_PREFIX);
     assert_route(&router, Method::HEAD, HEALTH_PREFIX);
@@ -100,4 +102,44 @@ fn test_register_routes_cover_representative_admin_paths() {
     assert_route(&router, Method::POST, &admin_path("/v3/kms/keys"));
     assert_route(&router, Method::GET, &admin_path("/v3/kms/keys"));
     assert_route(&router, Method::GET, &admin_path("/v3/kms/keys/test-key"));
+    assert_route(&router, Method::GET, "/rustfs/rpc/read_file_stream");
+    assert_route(&router, Method::HEAD, "/rustfs/rpc/read_file_stream");
+}
+
+#[test]
+fn test_phase5_admin_info_and_rpc_read_file_contract() {
+    let system_src = include_str!("handlers/system.rs");
+    let rpc_src = include_str!("rpc.rs");
+
+    let server_info_impl_marker = "impl Operation for ServerInfoHandler";
+    let server_info_impl_start = system_src
+        .find(server_info_impl_marker)
+        .expect("Expected impl Operation for ServerInfoHandler in handlers/system.rs");
+    let server_info_impl_block = &system_src[server_info_impl_start..];
+
+    assert!(
+        server_info_impl_block.contains("DefaultAdminUsecase::from_global()")
+            && server_info_impl_block.contains("execute_query_server_info(QueryServerInfoRequest { include_pools: true })"),
+        "admin server info path must be served through DefaultAdminUsecase::execute_query_server_info"
+    );
+
+    let register_route_marker = "pub fn register_rpc_route";
+    let register_route_start = rpc_src
+        .find(register_route_marker)
+        .expect("Expected register_rpc_route in rpc.rs");
+    let register_route_block = &rpc_src[register_route_start..];
+
+    let read_file_marker = "pub struct ReadFile {}";
+    let read_file_start = rpc_src.find(read_file_marker).expect("Expected ReadFile operation in rpc.rs");
+    let read_file_block = &rpc_src[read_file_start..];
+
+    assert!(
+        register_route_block.contains("format!(\"{}{}\", RPC_PREFIX, \"/read_file_stream\")"),
+        "rpc read_file_stream route path must remain registered with RPC_PREFIX"
+    );
+
+    assert!(
+        read_file_block.contains(".read_file_stream(&query.volume, &query.path, query.offset, query.length)"),
+        "rpc read_file_stream route must remain wired to disk.read_file_stream"
+    );
 }
diff --git a/rustfs/src/app/context.rs b/rustfs/src/app/context.rs
index 8280a4e5..c0ab28b2 100644
--- a/rustfs/src/app/context.rs
+++ b/rustfs/src/app/context.rs
@@ -384,14 +384,14 @@ pub fn default_buffer_config_interface() -> Arc<dyn BufferConfigInterface> {
     Arc::new(BufferConfigHandle)
 }
 
-static GLOBAL_APP_CONTEXT: OnceLock<Arc<AppContext>> = OnceLock::new();
+static APP_CONTEXT_SINGLETON: OnceLock<Arc<AppContext>> = OnceLock::new();
 
 /// Initialize global application context once and return the canonical instance.
 pub fn init_global_app_context(context: AppContext) -> Arc<AppContext> {
-    GLOBAL_APP_CONTEXT.get_or_init(|| Arc::new(context)).clone()
+    APP_CONTEXT_SINGLETON.get_or_init(|| Arc::new(context)).clone()
 }
 
 /// Get global application context if it has been initialized.
 pub fn get_global_app_context() -> Option<Arc<AppContext>> {
-    GLOBAL_APP_CONTEXT.get().cloned()
+    APP_CONTEXT_SINGLETON.get().cloned()
 }
diff --git a/rustfs/src/config/workload_profiles.rs b/rustfs/src/config/workload_profiles.rs
index 2de5b7e8..79b8a46e 100644
--- a/rustfs/src/config/workload_profiles.rs
+++ b/rustfs/src/config/workload_profiles.rs
@@ -24,7 +24,7 @@ use std::sync::OnceLock;
 use std::sync::atomic::{AtomicBool, Ordering};
 
 /// Global buffer configuration that can be set at application startup
-static GLOBAL_BUFFER_CONFIG: OnceLock<RustFSBufferConfig> = OnceLock::new();
+static BUFFER_CONFIG_SINGLETON: OnceLock<RustFSBufferConfig> = OnceLock::new();
 
 /// Global flag indicating whether buffer profiles are enabled
 static BUFFER_PROFILE_ENABLED: AtomicBool = AtomicBool::new(false);
@@ -60,14 +60,14 @@ pub fn is_buffer_profile_enabled() -> bool {
 /// init_global_buffer_config(RustFSBufferConfig::new(WorkloadProfile::AiTraining));
 /// ```
 pub fn init_global_buffer_config(config: RustFSBufferConfig) {
-    let _ = GLOBAL_BUFFER_CONFIG.set(config);
+    let _ = BUFFER_CONFIG_SINGLETON.set(config);
 }
 
 /// Get the global buffer configuration
 ///
 /// Returns the configured profile, or GeneralPurpose if not initialized.
 pub fn get_global_buffer_config() -> &'static RustFSBufferConfig {
-    GLOBAL_BUFFER_CONFIG.get_or_init(RustFSBufferConfig::default)
+    BUFFER_CONFIG_SINGLETON.get_or_init(RustFSBufferConfig::default)
 }
 
 /// Workload profile types that define buffer sizing strategies
diff --git a/rustfs/src/storage/ecfs_test.rs b/rustfs/src/storage/ecfs_test.rs
index 2a3b5f33..978bb4b3 100644
--- a/rustfs/src/storage/ecfs_test.rs
+++ b/rustfs/src/storage/ecfs_test.rs
@@ -359,6 +359,44 @@ mod tests {
         set_buffer_profile_enabled(false);
     }
 
+    #[test]
+    fn test_phase5_s3_entrypoints_delegate_to_usecases() {
+        fn assert_delegates_within_method(src: &str, signature: &str, delegation_call: &str, error_msg: &str) {
+            let sig_pos = src
+                .find(signature)
+                .unwrap_or_else(|| panic!("Expected to find method signature: {signature}"));
+
+            let after_sig = &src[sig_pos + signature.len()..];
+            let method_body_end_rel = after_sig.find("async fn ").unwrap_or(after_sig.len());
+            let method_body = &after_sig[..method_body_end_rel];
+
+            assert!(method_body.contains(delegation_call), "{error_msg}");
+        }
+
+        let src = include_str!("ecfs.rs");
+
+        assert_delegates_within_method(
+            src,
+            "async fn put_object(&self, req: S3Request<PutObjectInput>)",
+            "usecase.execute_put_object(self, req).await",
+            "put_object must delegate to DefaultObjectUsecase::execute_put_object",
+        );
+
+        assert_delegates_within_method(
+            src,
+            "async fn get_object(&self, req: S3Request<GetObjectInput>)",
+            "usecase.execute_get_object(req).await",
+            "get_object must delegate to DefaultObjectUsecase::execute_get_object",
+        );
+
+        assert_delegates_within_method(
+            src,
+            "async fn list_objects_v2(&self, req: S3Request<ListObjectsV2Input>)",
+            "usecase.execute_list_objects_v2(req).await",
+            "list_objects_v2 must delegate to DefaultBucketUsecase::execute_list_objects_v2",
+        );
+    }
+
     #[test]
     fn test_validate_list_object_unordered_with_delimiter() {
         // [1] Normal case: No delimiter specified.