diff --git a/gateway/platforms/api_server.py b/gateway/platforms/api_server.py
index 16708e725697..f01703ec9398 100644
--- a/gateway/platforms/api_server.py
+++ b/gateway/platforms/api_server.py
@@ -5367,30 +5367,12 @@ async def connect(self) -> bool:
             self._app.router.add_get("/v1/runs/{run_id}/events", self._handle_run_events)
             self._app.router.add_post("/v1/runs/{run_id}/approval", self._handle_run_approval)
             self._app.router.add_post("/v1/runs/{run_id}/stop", self._handle_stop_run)
-            # Store the adapter after native routes are registered. Local Hermes-Relay
-            # bootstrap shims use this key as a feature-detection hook; registering
-            # native routes first lets those shims no-op instead of shadowing the
-            # upstream session-control handlers.
-            self._app["api_server_adapter"] = self
-
-            # Start background sweep to clean up orphaned (unconsumed) run streams
-            sweep_task = asyncio.create_task(self._sweep_orphaned_runs())
-            try:
-                self._background_tasks.add(sweep_task)
-            except TypeError:
-                pass
-            if hasattr(sweep_task, "add_done_callback"):
-                sweep_task.add_done_callback(self._background_tasks.discard)
-            self._app.router.add_get("/api/sessions", self._handle_list_sessions)
-            self._app.router.add_post("/api/sessions", self._handle_create_session)
+            # Axiom/Relay compatibility routes that are still outside upstream's
+            # baseline session-control surface. Register these before exposing
+            # the adapter through app["api_server_adapter"] so Hermes-Relay's
+            # bootstrap hook sees the native fork routes and no-ops instead of
+            # injecting shadow handlers.
             self._app.router.add_get("/api/sessions/search", self._handle_search_sessions)
-            self._app.router.add_get("/api/sessions/{session_id}", self._handle_get_session)
-            self._app.router.add_get("/api/sessions/{session_id}/messages", self._handle_get_session_messages)
-            self._app.router.add_patch("/api/sessions/{session_id}", self._handle_update_session)
-            self._app.router.add_delete("/api/sessions/{session_id}", self._handle_delete_session)
-            self._app.router.add_post("/api/sessions/{session_id}/fork", self._handle_fork_session)
-            self._app.router.add_post("/api/sessions/{session_id}/chat", self._handle_session_chat)
-            self._app.router.add_post("/api/sessions/{session_id}/chat/stream", self._handle_session_chat_stream)
             self._app.router.add_get("/api/memory", self._handle_get_memory)
             self._app.router.add_post("/api/memory", self._handle_add_memory)
             self._app.router.add_patch("/api/memory", self._handle_replace_memory)
@@ -5401,6 +5383,21 @@ async def connect(self) -> bool:
             self._app.router.add_patch("/api/config", self._handle_update_config)
             self._app.router.add_get("/api/available-models", self._handle_available_models)
 
+            # Store the adapter after all native routes are registered. Local
+            # Hermes-Relay bootstrap shims use this key as a feature-detection
+            # hook; registering native routes first lets those shims no-op
+            # instead of shadowing first-class handlers.
+            self._app["api_server_adapter"] = self
+
+            # Start background sweep to clean up orphaned (unconsumed) run streams
+            sweep_task = asyncio.create_task(self._sweep_orphaned_runs())
+            try:
+                self._background_tasks.add(sweep_task)
+            except TypeError:
+                pass
+            if hasattr(sweep_task, "add_done_callback"):
+                sweep_task.add_done_callback(self._background_tasks.discard)
+
             # Refuse to start without authentication. The API server can
             # dispatch terminal-capable agent work, so every deployment needs
             # an explicit API_SERVER_KEY regardless of bind address.
diff --git a/tests/gateway/test_api_server.py b/tests/gateway/test_api_server.py
index 0363208b784e..9975ae322b4f 100644
--- a/tests/gateway/test_api_server.py
+++ b/tests/gateway/test_api_server.py
@@ -53,6 +53,42 @@ def test_returns_false_without_aiohttp(self):
         assert check_api_server_requirements() is False
 
 
+# ---------------------------------------------------------------------------
+# Route registration
+# ---------------------------------------------------------------------------
+
+
+def test_connect_registers_each_route_once():
+    """Regression guard: upstream-native session routes must not be re-added.
+
+    Hermes-Relay's bootstrap detects native routes by method/path. Registering
+    duplicate aiohttp routes makes route ownership ambiguous and can leave the
+    live API surface depending on registration order instead of the upstream
+    canonical handlers.
+    """
+    from collections import Counter
+    import inspect
+    import re
+
+    source = inspect.getsource(APIServerAdapter.connect)
+    registrations = [
+        (method.upper(), path)
+        for method, path in re.findall(
+            r'self\._app\.router\.add_(\w+)\("([^"]+)"',
+            source,
+        )
+    ]
+
+    duplicate_routes = {
+        route: count
+        for route, count in Counter(registrations).items()
+        if count > 1
+    }
+
+    assert duplicate_routes == {}
+    assert ("GET", "/api/sessions/search") in registrations
+
+
 # ---------------------------------------------------------------------------
 # ResponseStore
 # ---------------------------------------------------------------------------