diff --git a/src/openai/types/responses/response_text_delta_event.py b/src/openai/types/responses/response_text_delta_event.py
index 4f802abfd2..2cae46d188 100644
--- a/src/openai/types/responses/response_text_delta_event.py
+++ b/src/openai/types/responses/response_text_delta_event.py
@@ -1,4 +1,6 @@
 # File generated from our OpenAPI spec by Stainless. See CONTRIBUTING.md for details.
+# NOTE: logprobs field manually changed to Optional to support non-OpenAI providers
+# that may not include logprobs in streaming responses. See #2489.
 
 from typing import List, Optional
 from typing_extensions import Literal
@@ -45,7 +47,7 @@ class ResponseTextDeltaEvent(BaseModel):
     item_id: str
     """The ID of the output item that the text delta was added to."""
 
-    logprobs: List[Logprob]
+    logprobs: Optional[List[Logprob]] = None
     """The log probabilities of the tokens in the delta."""
 
     output_index: int
diff --git a/src/openai/types/responses/response_text_done_event.py b/src/openai/types/responses/response_text_done_event.py
index 75bd479870..ab89dbc65c 100644
--- a/src/openai/types/responses/response_text_done_event.py
+++ b/src/openai/types/responses/response_text_done_event.py
@@ -1,4 +1,6 @@
 # File generated from our OpenAPI spec by Stainless. See CONTRIBUTING.md for details.
+# NOTE: logprobs field manually changed to Optional to support non-OpenAI providers
+# that may not include logprobs in streaming responses. See #2489.
 
 from typing import List, Optional
 from typing_extensions import Literal
@@ -42,7 +44,7 @@ class ResponseTextDoneEvent(BaseModel):
     item_id: str
     """The ID of the output item that the text content is finalized."""
 
-    logprobs: List[Logprob]
+    logprobs: Optional[List[Logprob]] = None
     """The log probabilities of the tokens in the delta."""
 
     output_index: int
diff --git a/tests/test_response_event_logprobs.py b/tests/test_response_event_logprobs.py
new file mode 100644
index 0000000000..61e664559a
--- /dev/null
+++ b/tests/test_response_event_logprobs.py
@@ -0,0 +1,64 @@
+"""Tests for optional logprobs in response event types.
+
+Regression tests for https://github.com/openai/openai-python/issues/2489
+Non-OpenAI providers may not include logprobs in streaming responses.
+"""
+
+from openai.types.responses.response_text_done_event import ResponseTextDoneEvent
+from openai.types.responses.response_text_delta_event import ResponseTextDeltaEvent
+
+_DELTA_BASE = {
+    "content_index": 0,
+    "delta": "Hello",
+    "item_id": "item_1",
+    "output_index": 0,
+    "sequence_number": 1,
+    "type": "response.output_text.delta",
+}
+
+_DONE_BASE = {
+    "content_index": 0,
+    "item_id": "item_1",
+    "output_index": 0,
+    "sequence_number": 2,
+    "text": "Hello world",
+    "type": "response.output_text.done",
+}
+
+_SAMPLE_LOGPROBS = [{"token": "Hello", "logprob": -0.1, "top_logprobs": None}]
+
+
+class TestResponseTextDeltaEventLogprobs:
+    def test_without_logprobs(self) -> None:
+        event = ResponseTextDeltaEvent.model_validate(_DELTA_BASE)
+        assert event.logprobs is None
+
+    def test_with_logprobs(self) -> None:
+        data = {**_DELTA_BASE, "logprobs": _SAMPLE_LOGPROBS}
+        event = ResponseTextDeltaEvent.model_validate(data)
+        assert event.logprobs is not None
+        assert len(event.logprobs) == 1
+        assert event.logprobs[0].token == "Hello"
+
+    def test_with_empty_logprobs(self) -> None:
+        data = {**_DELTA_BASE, "logprobs": []}
+        event = ResponseTextDeltaEvent.model_validate(data)
+        assert event.logprobs == []
+
+
+class TestResponseTextDoneEventLogprobs:
+    def test_without_logprobs(self) -> None:
+        event = ResponseTextDoneEvent.model_validate(_DONE_BASE)
+        assert event.logprobs is None
+
+    def test_with_logprobs(self) -> None:
+        data = {**_DONE_BASE, "logprobs": _SAMPLE_LOGPROBS}
+        event = ResponseTextDoneEvent.model_validate(data)
+        assert event.logprobs is not None
+        assert len(event.logprobs) == 1
+        assert event.logprobs[0].token == "Hello"
+
+    def test_with_empty_logprobs(self) -> None:
+        data = {**_DONE_BASE, "logprobs": []}
+        event = ResponseTextDoneEvent.model_validate(data)
+        assert event.logprobs == []