diff --git a/clients/python/README.md b/clients/python/README.md
index 6af08cf10..ddff13e5b 100644
--- a/clients/python/README.md
+++ b/clients/python/README.md
@@ -10,7 +10,7 @@ This library provides a high level interface for interacting with a model regist
 ```py
 from model_registry import ModelRegistry
 
-registry = ModelRegistry(server_address="server-address", port=9090, author="author")
+registry = ModelRegistry("server-address", author="Ada Lovelace")  # Defaults to port 443
 
 model = registry.register_model(
     "my-model",  # model name
diff --git a/clients/python/src/model_registry/_client.py b/clients/python/src/model_registry/_client.py
index 5a3074e95..b59b1ec96 100644
--- a/clients/python/src/model_registry/_client.py
+++ b/clients/python/src/model_registry/_client.py
@@ -17,27 +17,25 @@ class ModelRegistry:
     def __init__(
         self,
         server_address: str,
-        port: int,
+        port: int = 443,
+        *,
         author: str,
-        client_key: str | None = None,
-        server_cert: str | None = None,
-        custom_ca: str | None = None,
+        custom_ca: bytes | None = None,
     ):
         """Constructor.
 
         Args:
             server_address: Server address.
-            port: Server port.
+            port: Server port. Defaults to 443.
+            custom_ca: The PEM-encoded root certificates as a byte string. Defaults to envvar CERT.
+
+        Keyword Args:
             author: Name of the author.
-            client_key: The PEM-encoded private key as a byte string.
-            server_cert: The PEM-encoded certificate as a byte string.
-            custom_ca: The PEM-encoded root certificates as a byte string.
+            custom_ca: The PEM-encoded root certificates as a byte string. Defaults to contents of path on envvar CERT.
         """
         # TODO: get args from env
         self._author = author
-        self._api = ModelRegistryAPIClient(
-            server_address, port, client_key, server_cert, custom_ca
-        )
+        self._api = ModelRegistryAPIClient(server_address, port, custom_ca)
 
     def _register_model(self, name: str) -> RegisteredModel:
         if rm := self._api.get_registered_model_by_params(name):
diff --git a/clients/python/src/model_registry/core.py b/clients/python/src/model_registry/core.py
index 9e57da09c..5f83fc5f9 100644
--- a/clients/python/src/model_registry/core.py
+++ b/clients/python/src/model_registry/core.py
@@ -2,6 +2,9 @@
 
 from __future__ import annotations
 
+import os
+from pathlib import Path
+
 from ml_metadata.proto import MetadataStoreClientConfig
 
 from .exceptions import StoreException
@@ -17,29 +20,30 @@ class ModelRegistryAPIClient:
     def __init__(
         self,
         server_address: str,
-        port: int,
-        client_key: str | None = None,
-        server_cert: str | None = None,
-        custom_ca: str | None = None,
+        port: int = 443,
+        custom_ca: bytes | None = None,
     ):
         """Constructor.
 
         Args:
             server_address: Server address.
-            port: Server port.
-            client_key: The PEM-encoded private key as a byte string.
-            server_cert: The PEM-encoded certificate as a byte string.
-            custom_ca: The PEM-encoded root certificates as a byte string.
+            custom_ca: The PEM-encoded root certificates as a byte string. Defaults to envvar CERT.
+            port: Server port. Defaults to 443.
         """
         config = MetadataStoreClientConfig()
+        if port == 443:
+            if not custom_ca:
+                ca_cert = os.environ.get("CERT")
+                if not ca_cert:
+                    msg = "CA certificate must be provided"
+                    raise StoreException(msg)
+                root_certs = Path(ca_cert).read_bytes()
+            else:
+                root_certs = custom_ca
+
+            config.ssl_config.custom_ca = root_certs
         config.host = server_address
         config.port = port
-        if client_key is not None:
-            config.ssl_config.client_key = client_key
-        if server_cert is not None:
-            config.ssl_config.server_cert = server_cert
-        if custom_ca is not None:
-            config.ssl_config.custom_ca = custom_ca
         self._store = MLMDStore(config)
 
     def _map(self, py_obj: ProtoBase) -> ProtoType: