fix(extra): respect Pydantic field aliases in response_format

src/mistralai/extra/utils/response_format.py

@@ -11,7 +11,7 @@ def response_format_from_pydantic_model(
     model: type[CustomPydanticModel],
 ) -> ResponseFormat:
     """Generate a strict JSON schema from a pydantic model."""
-    model_schema = rec_strict_json_schema(model.model_json_schema())
+    model_schema = rec_strict_json_schema(model.model_json_schema(by_alias=True))
     json_schema = JSONSchema.model_validate(
         {"name": model.__name__, "schema": model_schema, "strict": True}
     )

tests/test_response_format_alias.py

@@ -0,0 +1,47 @@
+"""Test that response_format_from_pydantic_model respects Pydantic field aliases."""
+
+from pydantic import BaseModel, Field
+
+from mistralai.extra.utils.response_format import response_format_from_pydantic_model
+
+
+class AliasedModel(BaseModel):
+    full_name: str = Field(alias="fullName")
+    phone_number: str = Field(alias="phoneNumber")
+
+
+class NoAliasModel(BaseModel):
+    name: str
+    age: int
+
+
+def test_response_format_uses_alias_keys():
+    """Schema properties should use alias names, not Python field names."""
+    result = response_format_from_pydantic_model(AliasedModel)
+    schema = result.json_schema.schema_definition
+
+    props = schema["properties"]
+    assert "fullName" in props, f"Expected 'fullName' in properties, got {list(props)}"
+    assert "phoneNumber" in props, f"Expected 'phoneNumber' in properties, got {list(props)}"
+    assert "full_name" not in props, "Python field name 'full_name' should not appear"
+    assert "phone_number" not in props, "Python field name 'phone_number' should not appear"
+
+
+def test_response_format_required_uses_aliases():
+    """Required field list should use alias names."""
+    result = response_format_from_pydantic_model(AliasedModel)
+    schema = result.json_schema.schema_definition
+
+    required = schema["required"]
+    assert "fullName" in required
+    assert "phoneNumber" in required
+
+
+def test_response_format_without_aliases_unchanged():
+    """Models without aliases should work as before."""
+    result = response_format_from_pydantic_model(NoAliasModel)
+    schema = result.json_schema.schema_definition
+
+    props = schema["properties"]
+    assert "name" in props
+    assert "age" in props