structured_output.py — langchain Source File

Source Code

"""Types for setting agent response formats."""

from __future__ import annotations

import json
import uuid
from dataclasses import dataclass, is_dataclass
from types import UnionType
from typing import (
    TYPE_CHECKING,
    Any,
    Generic,
    Literal,
    TypeVar,
    Union,
    get_args,
    get_origin,
)

from langchain_core.tools import BaseTool, StructuredTool
from pydantic import BaseModel, TypeAdapter
from typing_extensions import Self, is_typeddict

if TYPE_CHECKING:
    from collections.abc import Callable, Iterable

    from langchain_core.messages import AIMessage

# Supported schema types: Pydantic models, dataclasses, TypedDict, JSON schema dicts
SchemaT = TypeVar("SchemaT")

SchemaKind = Literal["pydantic", "dataclass", "typeddict", "json_schema"]


class StructuredOutputError(Exception):
    """Base class for structured output errors."""

    ai_message: AIMessage


class MultipleStructuredOutputsError(StructuredOutputError):
    """Raised when model returns multiple structured output tool calls when only one is expected."""

    def __init__(self, tool_names: list[str], ai_message: AIMessage) -> None:
        """Initialize `MultipleStructuredOutputsError`.

        Args:
            tool_names: The names of the tools called for structured output.
            ai_message: The AI message that contained the invalid multiple tool calls.
        """
        self.tool_names = tool_names
        self.ai_message = ai_message

        super().__init__(
            "Model incorrectly returned multiple structured responses "
            f"({', '.join(tool_names)}) when only one is expected."
        )


class StructuredOutputValidationError(StructuredOutputError):
// ... (403 more lines)