diff --git a/headroom/proxy/handlers/openai.py b/headroom/proxy/handlers/openai.py
index 1024238c3..d2a2e39f1 100644
--- a/headroom/proxy/handlers/openai.py
+++ b/headroom/proxy/handlers/openai.py
@@ -75,7 +75,11 @@ from headroom.proxy.outcome import RequestOutcome
 from headroom.proxy.passthrough import (
     custom_base_passthrough_telemetry as _custom_base_passthrough_telemetry,
 )
-from headroom.proxy.project_context import classify_project, set_current_project
+from headroom.proxy.project_context import (
+    classify_project,
+    get_current_project,
+    set_current_project,
+)
 from headroom.proxy.token_counting import gemini_output_tokens
 
 logger = logging.getLogger("headroom.proxy")
@@ -5726,8 +5730,11 @@ class OpenAIHandlerMixin:
         # Captured in closure so per-turn RequestOutcome can stamp it.
         client = classify_client(ws_headers)
         # WS sessions bypass the HTTP middleware, so bind the project here;
-        # per-turn outcome emission inside this task inherits the context.
-        set_current_project(classify_project(ws_headers))
+        # per-turn outcome emission inside this task inherits the context. An
+        # explicit X-Headroom-Project header wins; otherwise fall back to the
+        # /p/<name> path prefix already bound by WebSocketProjectPrefixMiddleware
+        # so prefix-only clients (aider, Copilot BYOK, Cursor) stay attributed.
+        set_current_project(classify_project(ws_headers) or get_current_project())
         metrics_for_inbound_ws = getattr(self, "metrics", None)
         if metrics_for_inbound_ws is not None and hasattr(
             metrics_for_inbound_ws, "record_inbound_request"
diff --git a/headroom/proxy/server.py b/headroom/proxy/server.py
index a9ac18caa..c03c76ee8 100644
--- a/headroom/proxy/server.py
+++ b/headroom/proxy/server.py
@@ -2364,6 +2364,22 @@ _is_known_websocket_callback_failure = is_known_websocket_callback_failure
 _tool_schema_saved_from_tags = tool_schema_saved_from_tags
 
 
+class WebSocketProjectPrefixMiddleware:
+    """Normalize project-prefixed WebSocket paths before route matching."""
+
+    def __init__(self, app: Any) -> None:
+        self.app = app
+
+    async def __call__(self, scope: Any, receive: Any, send: Any) -> None:
+        if scope["type"] == "websocket":
+            prefix_project = strip_project_path_prefix(scope)
+            headers = {
+                name.decode("latin-1"): value.decode("latin-1") for name, value in scope["headers"]
+            }
+            set_current_project(classify_project(headers) or prefix_project)
+        await self.app(scope, receive, send)
+
+
 def create_app(config: ProxyConfig | None = None) -> FastAPI:
     """Create FastAPI application."""
     if not FASTAPI_AVAILABLE:
@@ -2573,6 +2589,7 @@ def create_app(config: ProxyConfig | None = None) -> FastAPI:
         version=__version__,
         lifespan=lifespan,
     )
+    app.add_middleware(WebSocketProjectPrefixMiddleware)
     loop_health_state: LoopHealthState = {
         "status": "healthy",
         "known_failures": 0,
diff --git a/tests/test_provider_proxy_routes.py b/tests/test_provider_proxy_routes.py
index 7a6ebb599..fe7f9ddd0 100644
--- a/tests/test_provider_proxy_routes.py
+++ b/tests/test_provider_proxy_routes.py
@@ -10,6 +10,7 @@ from fastapi.responses import JSONResponse
 from fastapi.testclient import TestClient
 
 from headroom.providers.codex.runtime import CodexRoutingDecision
+from headroom.proxy.project_context import get_current_project
 from headroom.proxy.server import HeadroomProxy, ProxyConfig, create_app
 
 
@@ -481,6 +482,31 @@ def test_openai_response_websocket_aliases_delegate_to_openai_ws_handler(monkeyp
     ]
 
 
+def test_project_prefixed_openai_response_websocket_delegates_to_openai_ws_handler(
+    monkeypatch,
+) -> None:
+    seen_paths: list[str] = []
+    seen_projects: list[str | None] = []
+
+    async def fake_ws(self, websocket):  # type: ignore[no-untyped-def]
+        seen_paths.append(websocket.url.path)
+        seen_projects.append(get_current_project())
+        await websocket.accept()
+        await websocket.send_json({"path": websocket.url.path})
+        await websocket.close()
+
+    monkeypatch.setattr(HeadroomProxy, "handle_openai_responses_ws", fake_ws)
+
+    with TestClient(_app()) as client:
+        with client.websocket_connect("/p/test-project/v1/responses") as websocket:
+            assert websocket.receive_json() == {"path": "/v1/responses"}
+
+    assert seen_paths == ["/v1/responses"]
+    # The /p/<name> prefix is bound as the project even without a header, so a
+    # prefix-only Codex WS client is still attributed (not just routed).
+    assert seen_projects == ["test-project"]
+
+
 def test_openai_response_subpath_passthrough_returns_502_on_http_failure() -> None:
     class FailingAsyncClient:
         async def request(self, method, url, **kwargs):  # type: ignore[no-untyped-def]