diff --git a/webext/app/credential_manager_shim.py b/webext/app/credential_manager_shim.py
index 762613b..abdbf6b 100755
--- a/webext/app/credential_manager_shim.py
+++ b/webext/app/credential_manager_shim.py
@@ -16,6 +16,7 @@
 
 from dbus_next import Variant
 from dbus_next.aio import MessageBus
+from dbus_next.proxy_object import BaseProxyInterface
 from dbus_next.constants import MessageType
 from dbus_next.message import Message
 
@@ -25,6 +26,7 @@
 
 APP_ID = "@APP_ID@"
 DBUS_DOC_FILE = "@DBUS_DOC_FILE@"
+INTERFACE: Optional[BaseProxyInterface] = None
 
 
 def getMessage():
@@ -397,20 +399,31 @@ async def get_passkey(interface, options, origin, top_origin):
     }
 
     logging.debug("Sending request to D-Bus API")
-    rsp = await interface.call_get_credential(["", req])
-    if rsp["type"].value != "public-key":
+    request_event = create_portal_request_message_handler(interface.bus)
+    req = {
+        "handle_token": Variant("s", request_event.token),
+        "public_key": Variant("s", req_json),
+    }
+    if top_origin != origin:
+        req["top_origin"] = Variant("s", top_origin)
+    _rsp = await interface.call_get_credential("", origin, req)
+    result = await request_event.wait()
+    if result["type"].value != "public-key":
         raise Exception(
-            f"Invalid credential type received: expected 'public-key', received {rsp['type'].value}"
+            f"Invalid credential type received: expected 'public-key', received {result['type'].value}"
         )
 
     response_json = json.loads(
-        rsp["public_key"].value["authentication_response_json"].value
+        result["public_key"].value["authentication_response_json"].value
     )
     return response_json
 
 
-async def run(cmd, options, origin, top_origin):
-    logging.debug("Executing command")
+async def get_interface():
+    global INTERFACE
+    if INTERFACE and INTERFACE.bus.connected:
+        return INTERFACE
+
     bus = await MessageBus().connect()
     logging.debug("Connected to bus")
     import os
@@ -438,11 +451,17 @@ async def run(cmd, options, origin, top_origin):
         "/org/freedesktop/portal/desktop",
         introspection,
     )
-
     interface = proxy_object.get_interface(
         "org.freedesktop.portal.experimental.Credential"
     )
+    INTERFACE = interface
     logging.debug(f"Connected to interface at {interface.path}")
+    return INTERFACE
+
+
+async def run(cmd, options, origin, top_origin):
+    logging.debug("Executing command")
+    interface = await get_interface()
 
     if cmd == "create":
         if "publicKey" in options:
@@ -463,10 +482,33 @@ async def run(cmd, options, origin, top_origin):
                 f"Could not get unknown credential type: {options.keys()[0]}"
             )
     elif cmd == "getClientCapabilities":
-        rsp = await interface.call_get_client_capabilities()
-        response = {}
-        for name, val in rsp.items():
-            response[name] = val.value
+        conditional_create = await interface.get_conditional_create()
+        conditional_get = await interface.get_conditional_get()
+        hybrid_transport = await interface.get_hybrid_transport()
+        passkey_platform_authenticator = (
+            await interface.get_passkey_platform_authenticator()
+        )
+        user_verifying_platform_authenticator = (
+            await interface.get_user_verifying_platform_authenticator()
+        )
+        related_origins = await interface.get_related_origins()
+        signal_all_accepted_credentials = (
+            await interface.get_signal_all_accepted_credentials()
+        )
+        signal_current_user_details = await interface.get_signal_current_user_details()
+        signal_unknown_credential = await interface.get_signal_unknown_credential()
+
+        response = {
+            "conditional_create": conditional_create,
+            "conditional_get": conditional_get,
+            "hybrid_transport": hybrid_transport,
+            "passkey_platform_authenticator": passkey_platform_authenticator,
+            "user_verifying_platform_authenticator": user_verifying_platform_authenticator,
+            "related_origins": related_origins,
+            "signal_all_accepted_credentials": signal_all_accepted_credentials,
+            "signal_current_user_details": signal_current_user_details,
+            "signal_unknown_credential": signal_unknown_credential,
+        }
         return response
     else:
         raise Exception(f"unknown cmd: {cmd}")
@@ -477,6 +519,7 @@ async def run(cmd, options, origin, top_origin):
 
 async def main():
     logging.info("starting credential_manager_shim")
+
     while not quit.is_set():
         logging.debug("starting event loop message")
         receivedMessage = getMessage()