Support strict mode in NativeOutput (#2084)

Co-authored-by: Douwe Maan <douwe@pydantic.dev>

Author: severinh

pydantic_ai_slim/pydantic_ai/_output.py

@@ -182,6 +182,7 @@ def build(
                     _flatten_output_spec(output_spec.outputs),
                     name=output_spec.name,
                     description=output_spec.description,
+                    strict=output_spec.strict,
                 )
             )
         elif isinstance(output_spec, PromptedOutput):

pydantic_ai_slim/pydantic_ai/output.py

@@ -154,17 +154,21 @@ class NativeOutput(Generic[OutputDataT]):
     """The name of the structured output that will be passed to the model. If not specified and only one output is provided, the name of the output type or function will be used."""
     description: str | None
     """The description of the structured output that will be passed to the model. If not specified and only one output is provided, the docstring of the output type or function will be used."""
+    strict: bool | None
+    """Whether to use strict mode for the output, if the model supports it."""
 
     def __init__(
         self,
         outputs: OutputTypeOrFunction[OutputDataT] | Sequence[OutputTypeOrFunction[OutputDataT]],
         *,
         name: str | None = None,
         description: str | None = None,
+        strict: bool | None = None,
     ):
         self.outputs = outputs
         self.name = name
         self.description = description
+        self.strict = strict
 
 
 @dataclass(init=False)

tests/test_agent.py

@@ -15,6 +15,7 @@
 from pydantic_ai import Agent, ModelRetry, RunContext, UnexpectedModelBehavior, UserError, capture_run_messages
 from pydantic_ai._output import (
     NativeOutput,
+    NativeOutputSchema,
     OutputSpec,
     PromptedOutput,
     TextOutput,
@@ -1513,6 +1514,17 @@ class CityLocation(BaseModel):
     )
 
 
+def test_native_output_strict_mode():
+    class CityLocation(BaseModel):
+        city: str
+        country: str
+
+    agent = Agent(output_type=NativeOutput(CityLocation, strict=True))
+    output_schema = agent._output_schema  # pyright: ignore[reportPrivateUsage]
+    assert isinstance(output_schema, NativeOutputSchema)
+    assert output_schema.object_def.strict
+
+
 def test_prompted_output_function_with_retry():
     class Weather(BaseModel):
         temperature: float