Structured Output And Parsers

Integrator asks the model for JSON in the prompt and parses the text with json.loads, which breaks when the model wraps output in prose or code fences.

Use model.with_structured_output(MySchema) (Pydantic/TypedDict/JSON schema) so the framework coerces output to the typed object via the provider's native mechanism. The invoke result is the typed object, not raw text to hand-parse.

Integrator uses PydanticOutputParser but never injects parser.get_format_instructions() into the prompt, so the model emits free-form text the parser rejects.

When using an output parser (vs with_structured_output), insert parser.get_format_instructions() into the prompt so the model knows the exact schema, then parse the result. The format instructions and the parser must reference the same schema.

with_structured_output returns malformed results because the chosen method is not supported by the underlying provider integration.

Select the method (function_calling, json_mode, or json_schema) that the specific provider integration supports; not all providers support all methods. When swapping providers, re-verify method support rather than assuming portability.