diff --git a/services/protocol/openai_v1_chat_complete.py b/services/protocol/openai_v1_chat_complete.py
index 96beb7b..d6c4c25 100644
--- a/services/protocol/openai_v1_chat_complete.py
+++ b/services/protocol/openai_v1_chat_complete.py
@@ -65,32 +65,94 @@ def completion_response(
     }
 
 
-def stream_text_chat_completion(backend, messages: list[dict[str, Any]], model: str) -> Iterator[dict[str, Any]]:
+def stream_include_usage(body: dict[str, Any]) -> bool:
+    stream_options = body.get("stream_options")
+    return isinstance(stream_options, dict) and stream_options.get("include_usage") is True
+
+
+def completion_usage(
+    messages: list[dict[str, Any]],
+    model: str,
+    content: str,
+    reasoning_content: str = "",
+) -> dict[str, int]:
+    prompt_tokens = count_message_tokens(messages, model) if messages else 0
+    completion_tokens = count_text_tokens(content, model) if messages else 0
+    reasoning_tokens = count_text_tokens(reasoning_content, model) if messages and reasoning_content else 0
+    return {
+        "prompt_tokens": prompt_tokens,
+        "completion_tokens": completion_tokens + reasoning_tokens,
+        "total_tokens": prompt_tokens + completion_tokens + reasoning_tokens,
+    }
+
+
+def completion_usage_chunk(model: str, completion_id: str, created: int, usage: dict[str, int]) -> dict[str, Any]:
+    return {
+        "id": completion_id,
+        "object": "chat.completion.chunk",
+        "created": created,
+        "model": model,
+        "choices": [],
+        "usage": usage,
+    }
+
+
+def stream_chunk(chunk: dict[str, Any], include_usage: bool) -> dict[str, Any]:
+    if include_usage:
+        chunk = dict(chunk)
+        chunk["usage"] = None
+    return chunk
+
+
+def stream_text_chat_completion(
+    backend,
+    messages: list[dict[str, Any]],
+    model: str,
+    include_usage: bool = False,
+) -> Iterator[dict[str, Any]]:
     completion_id = f"chatcmpl-{uuid.uuid4().hex}"
     created = int(time.time())
     sent_role = False
+    content_parts: list[str] = []
     request = ConversationRequest(model=model, messages=messages)
     for delta_text in stream_text_deltas(backend, request):
+        content_parts.append(delta_text)
         if not sent_role:
             sent_role = True
-            yield completion_chunk(model, {"role": "assistant", "content": delta_text}, None, completion_id, created)
+            chunk = completion_chunk(model, {"role": "assistant", "content": delta_text}, None, completion_id, created)
         else:
-            yield completion_chunk(model, {"content": delta_text}, None, completion_id, created)
+            chunk = completion_chunk(model, {"content": delta_text}, None, completion_id, created)
+        yield stream_chunk(chunk, include_usage)
     if not sent_role:
-        yield completion_chunk(model, {"role": "assistant", "content": ""}, None, completion_id, created)
-    yield completion_chunk(model, {}, "stop", completion_id, created)
+        chunk = completion_chunk(model, {"role": "assistant", "content": ""}, None, completion_id, created)
+        yield stream_chunk(chunk, include_usage)
+    yield stream_chunk(completion_chunk(model, {}, "stop", completion_id, created), include_usage)
+    if include_usage:
+        yield completion_usage_chunk(
+            model,
+            completion_id,
+            created,
+            completion_usage(messages, model, "".join(content_parts)),
+        )
 
 
 def stream_grok_app_chat_completion(body: dict[str, Any], spec, messages: list[dict[str, Any]], model: str) -> Iterator[dict[str, Any]]:
+    include_usage = stream_include_usage(body)
     completion_id = f"chatcmpl-{uuid.uuid4().hex}"
     created = int(time.time())
     sent_role = False
+    content_parts: list[str] = []
+    reasoning_parts: list[str] = []
     for event in grok.app_chat_completion_events(body, spec, messages):
         token, thinking = grok.extract_app_chat_token(event)
         if not token:
             if grok.is_app_chat_final_event(event):
                 break
             continue
+        if thinking:
+            reasoning_parts.append(token)
+        else:
+            content_parts.append(token)
         if not sent_role:
             sent_role = True
             delta: dict[str, Any] = {"role": "assistant"}
@@ -98,30 +160,55 @@ def stream_grok_app_chat_completion(body: dict[str, Any], spec, messages: list[d
                 delta["reasoning_content"] = token
             else:
                 delta["content"] = token
-            yield completion_chunk(model, delta, None, completion_id, created)
+            yield stream_chunk(completion_chunk(model, delta, None, completion_id, created), include_usage)
             continue
         if thinking:
-            yield completion_chunk(model, {"reasoning_content": token}, None, completion_id, created)
+            chunk = completion_chunk(model, {"reasoning_content": token}, None, completion_id, created)
         else:
-            yield completion_chunk(model, {"content": token}, None, completion_id, created)
+            chunk = completion_chunk(model, {"content": token}, None, completion_id, created)
+        yield stream_chunk(chunk, include_usage)
     if not sent_role:
-        yield completion_chunk(model, {"role": "assistant", "content": ""}, None, completion_id, created)
-    yield completion_chunk(model, {}, "stop", completion_id, created)
+        chunk = completion_chunk(model, {"role": "assistant", "content": ""}, None, completion_id, created)
+        yield stream_chunk(chunk, include_usage)
+    yield stream_chunk(completion_chunk(model, {}, "stop", completion_id, created), include_usage)
+    if include_usage:
+        yield completion_usage_chunk(
+            model,
+            completion_id,
+            created,
+            completion_usage(messages, model, "".join(content_parts), "".join(reasoning_parts)),
+        )
 
 
 def stream_grok_chat_completion(body: dict[str, Any], spec, messages: list[dict[str, Any]], model: str) -> Iterator[dict[str, Any]]:
     if is_grok_app_chat_model(spec):
         yield from stream_grok_app_chat_completion(body, spec, messages, model)
         return
+    include_usage = stream_include_usage(body)
     completion_id = f"chatcmpl-{uuid.uuid4().hex}"
     created = int(time.time())
     response = grok.console_chat_completion(body, spec, messages)
     if response.reasoning_content:
-        yield completion_chunk(model, {"role": "assistant", "reasoning_content": response.reasoning_content}, None, completion_id, created)
-        yield completion_chunk(model, {"content": response.content}, None, completion_id, created)
+        chunk = completion_chunk(
+            model,
+            {"role": "assistant", "reasoning_content": response.reasoning_content},
+            None,
+            completion_id,
+            created,
+        )
+        yield stream_chunk(chunk, include_usage)
+        yield stream_chunk(completion_chunk(model, {"content": response.content}, None, completion_id, created), include_usage)
     else:
-        yield completion_chunk(model, {"role": "assistant", "content": response.content}, None, completion_id, created)
-    yield completion_chunk(model, {}, "stop", completion_id, created)
+        chunk = completion_chunk(model, {"role": "assistant", "content": response.content}, None, completion_id, created)
+        yield stream_chunk(chunk, include_usage)
+    yield stream_chunk(completion_chunk(model, {}, "stop", completion_id, created), include_usage)
+    if include_usage:
+        yield completion_usage_chunk(
+            model,
+            completion_id,
+            created,
+            completion_usage(messages, model, response.content, response.reasoning_content),
+        )
 
 
 def collect_chat_content(chunks: Iterable[dict[str, Any]]) -> str:
@@ -243,7 +330,7 @@ def handle(body: dict[str, Any]) -> dict[str, Any] | Iterator[dict[str, Any]]:
         spec = resolve_model(model)
         if spec.provider == GROK_PROVIDER:
             return stream_grok_chat_completion(body, spec, messages, model)
-        return stream_text_chat_completion(text_backend(), messages, model)
+        return stream_text_chat_completion(text_backend(), messages, model, stream_include_usage(body))
     if is_image_chat_request(body):
         return image_chat_response(body)
     model, messages = text_chat_parts(body)
diff --git a/test/test_grok_provider.py b/test/test_grok_provider.py
index d3f80fd..26a8bdf 100644
--- a/test/test_grok_provider.py
+++ b/test/test_grok_provider.py
@@ -406,6 +406,29 @@ def test_streaming_grok_console_completion_emits_reasoning_content(self) -> None
         self.assertEqual(chunks[1]["choices"][0]["delta"], {"content": "Hi"})
         self.assertEqual(chunks[2]["choices"][0]["finish_reason"], "stop")
 
+    def test_streaming_grok_console_completion_includes_usage_when_requested(self) -> None:
+        body = {
+            "model": "grok-4.20-reasoning",
+            "stream": True,
+            "stream_options": {"include_usage": True},
+            "messages": [{"role": "user", "content": "Hello"}],
+        }
+        with (
+            mock.patch.object(
+                grok,
+                "console_chat_completion",
+                return_value=grok.GrokConsoleCompletion(content="Hi", reasoning_content="think"),
+            ),
+            mock.patch.object(openai_v1_chat_complete, "count_message_tokens", return_value=11),
+            mock.patch.object(openai_v1_chat_complete, "count_text_tokens", side_effect=[2, 3]),
+        ):
+            chunks = list(openai_v1_chat_complete.handle(body))
+
+        self.assertIsNone(chunks[0]["usage"])
+        self.assertEqual(chunks[-2]["choices"][0]["finish_reason"], "stop")
+        self.assertEqual(chunks[-1]["choices"], [])
+        self.assertEqual(chunks[-1]["usage"], {"prompt_tokens": 11, "completion_tokens": 5, "total_tokens": 16})
+
     def test_streaming_grok_app_chat_completion_emits_reasoning_content(self) -> None:
         body = {
             "model": "grok-4.20-heavy",
@@ -423,6 +446,51 @@ def test_streaming_grok_app_chat_completion_emits_reasoning_content(self) -> Non
         self.assertEqual(chunks[1]["choices"][0]["delta"], {"content": "Hi"})
         self.assertEqual(chunks[-1]["choices"][0]["finish_reason"], "stop")
 
+    def test_streaming_grok_app_chat_completion_includes_usage_when_requested(self) -> None:
+        body = {
+            "model": "grok-4.20-heavy",
+            "stream": True,
+            "stream_options": {"include_usage": True},
+            "messages": [{"role": "user", "content": "Hello"}],
+        }
+        events = [
+            {"result": {"response": {"token": "think", "isThinking": True}}},
+            {"result": {"response": {"token": "Hi"}}},
+            {"result": {"response": {"token": " there", "messageTag": "final"}}},
+        ]
+        with (
+            mock.patch.object(grok, "app_chat_completion_events", return_value=iter(events)),
+            mock.patch.object(openai_v1_chat_complete, "count_message_tokens", return_value=7),
+            mock.patch.object(openai_v1_chat_complete, "count_text_tokens", side_effect=[4, 2]),
+        ):
+            chunks = list(openai_v1_chat_complete.handle(body))
+
+        self.assertIsNone(chunks[0]["usage"])
+        self.assertEqual(chunks[-2]["choices"][0]["finish_reason"], "stop")
+        self.assertEqual(chunks[-1]["choices"], [])
+        self.assertEqual(chunks[-1]["usage"], {"prompt_tokens": 7, "completion_tokens": 6, "total_tokens": 13})
+
+    def test_streaming_text_completion_includes_usage_when_requested(self) -> None:
+        body = {
+            "model": "auto",
+            "stream": True,
+            "stream_options": {"include_usage": True},
+            "messages": [{"role": "user", "content": "Hello"}],
+        }
+        with (
+            mock.patch.object(openai_v1_chat_complete, "ConversationRequest", return_value=object()),
+            mock.patch.object(openai_v1_chat_complete, "stream_text_deltas", return_value=iter(["Hi", " there"])),
+            mock.patch.object(openai_v1_chat_complete, "count_message_tokens", return_value=5),
+            mock.patch.object(openai_v1_chat_complete, "count_text_tokens", return_value=8),
+        ):
+            chunks = list(openai_v1_chat_complete.handle(body))
+
+        self.assertEqual(chunks[0]["choices"][0]["delta"], {"role": "assistant", "content": "Hi"})
+        self.assertIsNone(chunks[0]["usage"])
+        self.assertEqual(chunks[-2]["choices"][0]["finish_reason"], "stop")
+        self.assertEqual(chunks[-1]["choices"], [])
+        self.assertEqual(chunks[-1]["usage"], {"prompt_tokens": 5, "completion_tokens": 8, "total_tokens": 13})
+
     def test_non_streaming_grok_app_chat_completion_includes_reasoning_content(self) -> None:
         body = {
             "model": "grok-4.20-heavy",