fix: handle BaseModel input in convert_to_model

lib/crewai/src/crewai/task.py

@@ -1110,7 +1110,7 @@ Follow these guidelines:
         )
 
     def _export_output(
-        self, result: str
+        self, result: str | BaseModel
     ) -> tuple[BaseModel | None, dict[str, Any] | None]:
         pydantic_output: BaseModel | None = None
         json_output: dict[str, Any] | None = None

lib/crewai/src/crewai/utilities/converter.py

@@ -153,16 +153,18 @@ class Converter(OutputConverter):
 
 
 def convert_to_model(
-    result: str,
+    result: str | BaseModel,
     output_pydantic: type[BaseModel] | None,
     output_json: type[BaseModel] | None,
     agent: Agent | BaseAgent | None = None,
     converter_cls: type[Converter] | None = None,
 ) -> dict[str, Any] | BaseModel | str:
-    """Convert a result string to a Pydantic model or JSON.
+    """Convert a result to a Pydantic model or JSON.
 
     Args:
-        result: The result string to convert.
+        result: The result to convert. Usually a JSON string, but a Pydantic
+            instance is also accepted when an upstream caller already produced
+            a structured object.
         output_pydantic: The Pydantic model class to convert to.
         output_json: The Pydantic model class to convert to JSON.
         agent: The agent instance.
@@ -175,6 +177,11 @@ def convert_to_model(
     if model is None:
         return result
 
+    if isinstance(result, BaseModel):
+        if isinstance(result, model):
+            return result.model_dump() if output_json else result
+        result = result.model_dump_json()
+
     if converter_cls:
         return convert_with_instructions(
             result=result,

lib/crewai/tests/test_task_guardrails.py

@@ -690,6 +690,27 @@ def test_multiple_guardrails_with_pydantic_output():
     assert parsed["processed"] is True
 
 
+def test_export_output_accepts_pydantic_input():
+    """Regression test for #5458: _export_output must not crash with TypeError
+    when called with a Pydantic instance (e.g. when an upstream caller passes
+    an already-converted model from a context task)."""
+    from pydantic import BaseModel
+
+    class StructuredResult(BaseModel):
+        value: str
+
+    task = create_smart_task(
+        description="Test pydantic export",
+        expected_output="Structured output",
+        output_pydantic=StructuredResult,
+    )
+
+    instance = StructuredResult(value="ok")
+    pydantic_output, json_output = task._export_output(instance)
+    assert pydantic_output is instance
+    assert json_output is None
+
+
 def test_guardrails_vs_single_guardrail_mutual_exclusion():
     """Test that guardrails list nullifies single guardrail."""
 

lib/crewai/tests/utilities/test_converter.py

@@ -87,6 +87,31 @@ def test_convert_to_model_with_no_model() -> None:
     assert output == "Plain text"
 
 
+def test_convert_to_model_with_basemodel_input_matching_pydantic() -> None:
+    instance = SimpleModel(name="John", age=30)
+    output = convert_to_model(instance, SimpleModel, None, None)
+    assert output is instance
+
+
+def test_convert_to_model_with_basemodel_input_matching_json() -> None:
+    instance = SimpleModel(name="John", age=30)
+    output = convert_to_model(instance, None, SimpleModel, None)
+    assert output == {"name": "John", "age": 30}
+
+
+def test_convert_to_model_with_basemodel_input_different_class() -> None:
+    class OtherModel(BaseModel):
+        name: str
+        age: int
+        extra: str = "default"
+
+    instance = OtherModel(name="John", age=30, extra="ignored")
+    output = convert_to_model(instance, SimpleModel, None, None)
+    assert isinstance(output, SimpleModel)
+    assert output.name == "John"
+    assert output.age == 30
+
+
 def test_convert_to_model_with_special_characters() -> None:
     json_string_test = """
     {

uv.lock

@@ -13,7 +13,7 @@ resolution-markers = [
 ]
 
 [options]
-exclude-newer = "2026-04-28T07:00:00Z"
+exclude-newer = "2026-04-27T16:00:00Z"
 
 [manifest]
 members = [