diff --git a/src/openai/_base_client.py b/src/openai/_base_client.py
index 4933c8e2fe..a6fc653f67 100644
--- a/src/openai/_base_client.py
+++ b/src/openai/_base_client.py
@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import sys
+import os
 import json
 import time
 import uuid
@@ -831,11 +832,31 @@ def _idempotency_key(self) -> str:
         return f"stainless-python-retry-{uuid.uuid4()}"
 
 
+def _sanitize_no_proxy() -> None:
+    """Sanitize NO_PROXY/no_proxy env vars that contain newline characters.
+
+    httpx's ``get_environment_proxies()`` only splits by comma, not by newline.
+    When NO_PROXY contains newlines (common in Docker/.env files), the newline
+    becomes part of the hostname and httpx raises ``InvalidURL`` (issue #3303).
+    """
+    for key in ("NO_PROXY", "no_proxy"):
+        val = os.environ.get(key)
+        if val and "\n" in val:
+            os.environ[key] = ",".join(
+                part.strip() for part in val.replace("\n", ",").split(",") if part.strip()
+            )
+
+
 class _DefaultHttpxClient(httpx.Client):
     def __init__(self, **kwargs: Any) -> None:
         kwargs.setdefault("timeout", DEFAULT_TIMEOUT)
         kwargs.setdefault("limits", DEFAULT_CONNECTION_LIMITS)
         kwargs.setdefault("follow_redirects", True)
+        # Sanitize NO_PROXY environment variable: httpx's get_environment_proxies()
+        # only splits by comma, not by newline.  When NO_PROXY contains newlines
+        # (common in Docker/.env files), the newline becomes part of the hostname
+        # and httpx raises InvalidURL.  See issue #3303.
+        _sanitize_no_proxy()
         super().__init__(**kwargs)
 
 
@@ -1423,6 +1444,8 @@ def __init__(self, **kwargs: Any) -> None:
         kwargs.setdefault("timeout", DEFAULT_TIMEOUT)
         kwargs.setdefault("limits", DEFAULT_CONNECTION_LIMITS)
         kwargs.setdefault("follow_redirects", True)
+        # Sanitize NO_PROXY for async clients too — see _sanitize_no_proxy.
+        _sanitize_no_proxy()
         super().__init__(**kwargs)
 
 
diff --git a/src/openai/lib/_parsing/_responses.py b/src/openai/lib/_parsing/_responses.py
index c607587ec1..abf3eb2217 100644
--- a/src/openai/lib/_parsing/_responses.py
+++ b/src/openai/lib/_parsing/_responses.py
@@ -58,7 +58,13 @@ def parse_response(
 ) -> ParsedResponse[TextFormatT]:
     output_list: List[ParsedResponseOutputItem[TextFormatT]] = []
 
-    for output in response.output:
+    # Guard against `response.output` being `None` (observed in the chatgpt.com
+    # Codex backend's consolidated `response.completed` event — see issue #3325).
+    # When the streaming accumulator has already collected output items, it
+    # injects them into the response before calling this function, so reaching
+    # here with `None` means the stream genuinely had no output items and an
+    # empty list is the correct result.
+    for output in response.output or []:
         if output.type == "message":
             content_list: List[ParsedContent[TextFormatT]] = []
             for item in output.content:
diff --git a/src/openai/lib/streaming/responses/_responses.py b/src/openai/lib/streaming/responses/_responses.py
index 6975a9260d..617e5e00c6 100644
--- a/src/openai/lib/streaming/responses/_responses.py
+++ b/src/openai/lib/streaming/responses/_responses.py
@@ -357,11 +357,34 @@ def accumulate_event(self, event: RawResponseStreamEvent) -> ParsedResponseSnaps
             if output.type == "function_call":
                 output.arguments += event.delta
         elif event.type == "response.completed":
-            self._completed_response = parse_response(
-                text_format=self._text_format,
-                response=event.response,
-                input_tools=self._input_tools,
-            )
+            # The chatgpt.com Codex backend sometimes sends `response.output: null`
+            # in the consolidated `response.completed` event even when valid
+            # `output_item.done` events were streamed earlier (see issue #3325).
+            # `parse_response()` guards against `None` with `response.output or []`,
+            # but that would discard the already-accumulated `snapshot.output` and
+            # emit an empty final response.  When the completed event has no
+            # output but the snapshot has accumulated items, inject the streamed
+            # items into a shallow copy of the response so `parse_response()` can
+            # still run its text_format / parsed_arguments logic on them.
+            if event.response.output is None and snapshot.output:
+                response_with_output = construct_type_unchecked(
+                    type_=type(event.response),
+                    value={
+                        **event.response.to_dict(),
+                        "output": [item.to_dict() for item in snapshot.output],
+                    },
+                )
+                self._completed_response = parse_response(
+                    text_format=self._text_format,
+                    response=response_with_output,
+                    input_tools=self._input_tools,
+                )
+            else:
+                self._completed_response = parse_response(
+                    text_format=self._text_format,
+                    response=event.response,
+                    input_tools=self._input_tools,
+                )
 
         return snapshot