Enhance Gemini usage tracking to collect comprehensive token data

pydantic_ai_slim/pydantic_ai/models/gemini.py

@@ -463,13 +463,12 @@ async def _get_gemini_responses(self) -> AsyncIterator[_GeminiResponse]:
             responses_to_yield = gemini_responses[:-1]
             for r in responses_to_yield[current_gemini_response_index:]:
                 current_gemini_response_index += 1
-                self._usage += _metadata_as_usage(r)
                 yield r
 
         # Now yield the final response, which should be complete
         if gemini_responses:  # pragma: no branch
             r = gemini_responses[-1]
-            self._usage += _metadata_as_usage(r)
+            self._usage = _metadata_as_usage(r)
             yield r
 
     @property
@@ -770,8 +769,17 @@ class _GeminiCandidates(TypedDict):
     safety_ratings: NotRequired[Annotated[list[_GeminiSafetyRating], pydantic.Field(alias='safetyRatings')]]
 
 
+class _GeminiModalityTokenCount(TypedDict):
+    """See <https://ai.google.dev/api/generate-content#modalitytokencount>."""
+
+    modality: Annotated[
+        Literal['MODALITY_UNSPECIFIED', 'TEXT', 'IMAGE', 'VIDEO', 'AUDIO', 'DOCUMENT'], pydantic.Field(alias='modality')
+    ]
+    token_count: Annotated[int, pydantic.Field(alias='tokenCount', default=0)]
+
+
 class _GeminiUsageMetaData(TypedDict, total=False):
-    """See <https://ai.google.dev/api/generate-content#FinishReason>.
+    """See <https://ai.google.dev/api/generate-content#UsageMetadata>.
 
     The docs suggest all fields are required, but some are actually not required, so we assume they are all optional.
     """
@@ -780,6 +788,20 @@ class _GeminiUsageMetaData(TypedDict, total=False):
     candidates_token_count: NotRequired[Annotated[int, pydantic.Field(alias='candidatesTokenCount')]]
     total_token_count: Annotated[int, pydantic.Field(alias='totalTokenCount')]
     cached_content_token_count: NotRequired[Annotated[int, pydantic.Field(alias='cachedContentTokenCount')]]
+    thoughts_token_count: NotRequired[Annotated[int, pydantic.Field(alias='thoughtsTokenCount')]]
+    tool_use_prompt_token_count: NotRequired[Annotated[int, pydantic.Field(alias='toolUsePromptTokenCount')]]
+    prompt_tokens_details: NotRequired[
+        Annotated[list[_GeminiModalityTokenCount], pydantic.Field(alias='promptTokensDetails')]
+    ]
+    cache_tokens_details: NotRequired[
+        Annotated[list[_GeminiModalityTokenCount], pydantic.Field(alias='cacheTokensDetails')]
+    ]
+    candidates_tokens_details: NotRequired[
+        Annotated[list[_GeminiModalityTokenCount], pydantic.Field(alias='candidatesTokensDetails')]
+    ]
+    tool_use_prompt_tokens_details: NotRequired[
+        Annotated[list[_GeminiModalityTokenCount], pydantic.Field(alias='toolUsePromptTokensDetails')]
+    ]
 
 
 def _metadata_as_usage(response: _GeminiResponse) -> usage.Usage:
@@ -788,7 +810,21 @@ def _metadata_as_usage(response: _GeminiResponse) -> usage.Usage:
         return usage.Usage()  # pragma: no cover
     details: dict[str, int] = {}
     if cached_content_token_count := metadata.get('cached_content_token_count'):
-        details['cached_content_token_count'] = cached_content_token_count  # pragma: no cover
+        details['cached_content_tokens'] = cached_content_token_count  # pragma: no cover
+
+    if thoughts_token_count := metadata.get('thoughts_token_count'):
+        details['thoughts_tokens'] = thoughts_token_count
+
+    if tool_use_prompt_token_count := metadata.get('tool_use_prompt_token_count'):
+        details['tool_use_prompt_tokens'] = tool_use_prompt_token_count  # pragma: no cover
+
+    for key, metadata_details in metadata.items():
+        if key.endswith('_details') and metadata_details:
+            metadata_details = cast(list[_GeminiModalityTokenCount], metadata_details)
+            suffix = key.removesuffix('_details')
+            for detail in metadata_details:
+                details[f'{detail["modality"].lower()}_{suffix}'] = detail['token_count']
+
     return usage.Usage(
         request_tokens=metadata.get('prompt_token_count', 0),
         response_tokens=metadata.get('candidates_token_count', 0),

pydantic_ai_slim/pydantic_ai/models/google.py

@@ -399,7 +399,7 @@ class GeminiStreamedResponse(StreamedResponse):
 
     async def _get_event_iterator(self) -> AsyncIterator[ModelResponseStreamEvent]:
         async for chunk in self._response:
-            self._usage += _metadata_as_usage(chunk)
+            self._usage = _metadata_as_usage(chunk)
 
             assert chunk.candidates is not None
             candidate = chunk.candidates[0]
@@ -490,17 +490,28 @@ def _metadata_as_usage(response: GenerateContentResponse) -> usage.Usage:
     metadata = response.usage_metadata
     if metadata is None:
         return usage.Usage()  # pragma: no cover
-    # TODO(Marcelo): We exclude the `prompt_tokens_details` and `candidate_token_details` fields because on
-    # `usage.Usage.incr``, it will try to sum non-integer values with integers, which will fail. We should probably
-    # handle this in the `Usage` class.
-    details = metadata.model_dump(
-        exclude={'prompt_tokens_details', 'candidates_tokens_details', 'traffic_type'},
-        exclude_defaults=True,
-    )
+    metadata = metadata.model_dump(exclude_defaults=True)
+
+    details: dict[str, int] = {}
+    if cached_content_token_count := metadata.get('cached_content_token_count'):
+        details['cached_content_tokens'] = cached_content_token_count  # pragma: no cover
+
+    if thoughts_token_count := metadata.get('thoughts_token_count'):
+        details['thoughts_tokens'] = thoughts_token_count
+
+    if tool_use_prompt_token_count := metadata.get('tool_use_prompt_token_count'):
+        details['tool_use_prompt_tokens'] = tool_use_prompt_token_count  # pragma: no cover
+
+    for key, metadata_details in metadata.items():
+        if key.endswith('_details') and metadata_details:
+            suffix = key.removesuffix('_details')
+            for detail in metadata_details:
+                details[f'{detail["modality"].lower()}_{suffix}'] = detail['token_count']
+
     return usage.Usage(
-        request_tokens=details.pop('prompt_token_count', 0),
-        response_tokens=details.pop('candidates_token_count', 0),
-        total_tokens=details.pop('total_token_count', 0),
+        request_tokens=metadata.get('prompt_token_count', 0),
+        response_tokens=metadata.get('candidates_token_count', 0),
+        total_tokens=metadata.get('total_token_count', 0),
         details=details,
     )
 

tests/models/test_gemini.py

@@ -739,12 +739,12 @@ async def test_stream_text(get_gemini_client: GetGeminiClient):
                 'Hello world',
             ]
         )
-    assert result.usage() == snapshot(Usage(requests=1, request_tokens=2, response_tokens=4, total_tokens=6))
+    assert result.usage() == snapshot(Usage(requests=1, request_tokens=1, response_tokens=2, total_tokens=3))
 
     async with agent.run_stream('Hello') as result:
         chunks = [chunk async for chunk in result.stream_text(delta=True, debounce_by=None)]
         assert chunks == snapshot(['Hello ', 'world'])
-    assert result.usage() == snapshot(Usage(requests=1, request_tokens=2, response_tokens=4, total_tokens=6))
+    assert result.usage() == snapshot(Usage(requests=1, request_tokens=1, response_tokens=2, total_tokens=3))
 
 
 async def test_stream_invalid_unicode_text(get_gemini_client: GetGeminiClient):
@@ -776,7 +776,7 @@ async def test_stream_invalid_unicode_text(get_gemini_client: GetGeminiClient):
     async with agent.run_stream('Hello') as result:
         chunks = [chunk async for chunk in result.stream(debounce_by=None)]
         assert chunks == snapshot(['abc', 'abc€def', 'abc€def'])
-    assert result.usage() == snapshot(Usage(requests=1, request_tokens=2, response_tokens=4, total_tokens=6))
+    assert result.usage() == snapshot(Usage(requests=1, request_tokens=1, response_tokens=2, total_tokens=3))
 
 
 async def test_stream_text_no_data(get_gemini_client: GetGeminiClient):
@@ -847,7 +847,7 @@ async def bar(y: str) -> str:
     async with agent.run_stream('Hello') as result:
         response = await result.get_output()
         assert response == snapshot((1, 2))
-    assert result.usage() == snapshot(Usage(requests=2, request_tokens=3, response_tokens=6, total_tokens=9))
+    assert result.usage() == snapshot(Usage(requests=2, request_tokens=2, response_tokens=4, total_tokens=6))
     assert result.all_messages() == snapshot(
         [
             ModelRequest(parts=[UserPromptPart(content='Hello', timestamp=IsNow(tz=timezone.utc))]),
@@ -856,7 +856,7 @@ async def bar(y: str) -> str:
                     ToolCallPart(tool_name='foo', args={'x': 'a'}, tool_call_id=IsStr()),
                     ToolCallPart(tool_name='bar', args={'y': 'b'}, tool_call_id=IsStr()),
                 ],
-                usage=Usage(request_tokens=2, response_tokens=4, total_tokens=6),
+                usage=Usage(request_tokens=1, response_tokens=2, total_tokens=3, details={}),
                 model_name='gemini-1.5-flash',
                 timestamp=IsNow(tz=timezone.utc),
             ),
@@ -872,7 +872,7 @@ async def bar(y: str) -> str:
             ),
             ModelResponse(
                 parts=[ToolCallPart(tool_name='final_result', args={'response': [1, 2]}, tool_call_id=IsStr())],
-                usage=Usage(request_tokens=1, response_tokens=2, total_tokens=3),
+                usage=Usage(request_tokens=1, response_tokens=2, total_tokens=3, details={}),
                 model_name='gemini-1.5-flash',
                 timestamp=IsNow(tz=timezone.utc),
             ),
@@ -1103,7 +1103,13 @@ async def get_image() -> BinaryContent:
                     ),
                     ToolCallPart(tool_name='get_image', args={}, tool_call_id=IsStr()),
                 ],
-                usage=Usage(requests=1, request_tokens=38, response_tokens=28, total_tokens=427, details={}),
+                usage=Usage(
+                    requests=1,
+                    request_tokens=38,
+                    response_tokens=28,
+                    total_tokens=427,
+                    details={'thoughts_tokens': 361, 'text_prompt_tokens': 38},
+                ),
                 model_name='gemini-2.5-pro-preview-03-25',
                 timestamp=IsDatetime(),
                 vendor_details={'finish_reason': 'STOP'},
@@ -1127,7 +1133,13 @@ async def get_image() -> BinaryContent:
             ),
             ModelResponse(
                 parts=[TextPart(content='The image shows a kiwi fruit, sliced in half.')],
-                usage=Usage(requests=1, request_tokens=360, response_tokens=11, total_tokens=572, details={}),
+                usage=Usage(
+                    requests=1,
+                    request_tokens=360,
+                    response_tokens=11,
+                    total_tokens=572,
+                    details={'thoughts_tokens': 201, 'text_prompt_tokens': 102, 'image_prompt_tokens': 258},
+                ),
                 model_name='gemini-2.5-pro-preview-03-25',
                 timestamp=IsDatetime(),
                 vendor_details={'finish_reason': 'STOP'},
@@ -1250,7 +1262,13 @@ async def test_gemini_model_instructions(allow_model_requests: None, gemini_api_
             ),
             ModelResponse(
                 parts=[TextPart(content='The capital of France is Paris.\n')],
-                usage=Usage(requests=1, request_tokens=13, response_tokens=8, total_tokens=21, details={}),
+                usage=Usage(
+                    requests=1,
+                    request_tokens=13,
+                    response_tokens=8,
+                    total_tokens=21,
+                    details={'text_prompt_tokens': 13, 'text_candidates_tokens': 8},
+                ),
                 model_name='gemini-1.5-flash',
                 timestamp=IsDatetime(),
                 vendor_details={'finish_reason': 'STOP'},

tests/models/test_google.py

@@ -65,7 +65,15 @@ async def test_google_model(allow_model_requests: None, google_provider: GoogleP
 
     result = await agent.run('Hello!')
     assert result.output == snapshot('Hello there! How can I help you today?\n')
-    assert result.usage() == snapshot(Usage(requests=1, request_tokens=7, response_tokens=11, total_tokens=18))
+    assert result.usage() == snapshot(
+        Usage(
+            requests=1,
+            request_tokens=7,
+            response_tokens=11,
+            total_tokens=18,
+            details={'text_prompt_tokens': 7, 'text_candidates_tokens': 11},
+        )
+    )
     assert result.all_messages() == snapshot(
         [
             ModelRequest(
@@ -82,7 +90,13 @@ async def test_google_model(allow_model_requests: None, google_provider: GoogleP
             ),
             ModelResponse(
                 parts=[TextPart(content='Hello there! How can I help you today?\n')],
-                usage=Usage(requests=1, request_tokens=7, response_tokens=11, total_tokens=18, details={}),
+                usage=Usage(
+                    requests=1,
+                    request_tokens=7,
+                    response_tokens=11,
+                    total_tokens=18,
+                    details={'text_prompt_tokens': 7, 'text_candidates_tokens': 11},
+                ),
                 model_name='gemini-1.5-flash',
                 timestamp=IsDatetime(),
                 vendor_details={'finish_reason': 'STOP'},
@@ -115,7 +129,15 @@ async def temperature(city: str, date: datetime.date) -> str:
 
     result = await agent.run('What was the temperature in London 1st January 2022?', output_type=Response)
     assert result.output == snapshot({'temperature': '30°C', 'date': datetime.date(2022, 1, 1), 'city': 'London'})
-    assert result.usage() == snapshot(Usage(requests=2, request_tokens=224, response_tokens=35, total_tokens=259))
+    assert result.usage() == snapshot(
+        Usage(
+            requests=2,
+            request_tokens=224,
+            response_tokens=35,
+            total_tokens=259,
+            details={'text_prompt_tokens': 224, 'text_candidates_tokens': 35},
+        )
+    )
     assert result.all_messages() == snapshot(
         [
             ModelRequest(
@@ -136,7 +158,13 @@ async def temperature(city: str, date: datetime.date) -> str:
                         tool_name='temperature', args={'date': '2022-01-01', 'city': 'London'}, tool_call_id=IsStr()
                     )
                 ],
-                usage=Usage(requests=1, request_tokens=101, response_tokens=14, total_tokens=115, details={}),
+                usage=Usage(
+                    requests=1,
+                    request_tokens=101,
+                    response_tokens=14,
+                    total_tokens=115,
+                    details={'text_prompt_tokens': 101, 'text_candidates_tokens': 14},
+                ),
                 model_name='gemini-1.5-flash',
                 timestamp=IsDatetime(),
                 vendor_details={'finish_reason': 'STOP'},
@@ -156,7 +184,13 @@ async def temperature(city: str, date: datetime.date) -> str:
                         tool_call_id=IsStr(),
                     )
                 ],
-                usage=Usage(requests=1, request_tokens=123, response_tokens=21, total_tokens=144, details={}),
+                usage=Usage(
+                    requests=1,
+                    request_tokens=123,
+                    response_tokens=21,
+                    total_tokens=144,
+                    details={'text_prompt_tokens': 123, 'text_candidates_tokens': 21},
+                ),
                 model_name='gemini-1.5-flash',
                 timestamp=IsDatetime(),
                 vendor_details={'finish_reason': 'STOP'},
@@ -214,7 +248,7 @@ async def get_capital(country: str) -> str:
                     request_tokens=57,
                     response_tokens=15,
                     total_tokens=173,
-                    details={'thoughts_token_count': 101},
+                    details={'thoughts_tokens': 101, 'text_prompt_tokens': 57},
                 ),
                 model_name='models/gemini-2.5-pro-preview-05-06',
                 timestamp=IsDatetime(),
@@ -236,7 +270,13 @@ async def get_capital(country: str) -> str:
                         content='I am sorry, I cannot fulfill this request. The country you provided is not supported.'
                     )
                 ],
-                usage=Usage(requests=1, request_tokens=104, response_tokens=18, total_tokens=122, details={}),
+                usage=Usage(
+                    requests=1,
+                    request_tokens=104,
+                    response_tokens=18,
+                    total_tokens=122,
+                    details={'text_prompt_tokens': 104},
+                ),
                 model_name='models/gemini-2.5-pro-preview-05-06',
                 timestamp=IsDatetime(),
                 vendor_details={'finish_reason': 'STOP'},
@@ -493,7 +533,13 @@ def instructions() -> str:
             ),
             ModelResponse(
                 parts=[TextPart(content='The capital of France is Paris.\n')],
-                usage=Usage(requests=1, request_tokens=13, response_tokens=8, total_tokens=21, details={}),
+                usage=Usage(
+                    requests=1,
+                    request_tokens=13,
+                    response_tokens=8,
+                    total_tokens=21,
+                    details={'text_prompt_tokens': 13, 'text_candidates_tokens': 8},
+                ),
                 model_name='gemini-2.0-flash',
                 timestamp=IsDatetime(),
                 vendor_details={'finish_reason': 'STOP'},