dump.py — langchain Source File

Source Code

"""Serialize LangChain objects to JSON.

Provides `dumps` (to JSON string) and `dumpd` (to dict) for serializing
`Serializable` objects.

## Escaping

During serialization, plain dicts (user data) that contain an `'lc'` key are escaped
by wrapping them: `{"__lc_escaped__": {...original...}}`. This prevents injection
attacks where malicious data could trick the deserializer into instantiating
arbitrary classes. The escape marker is removed during deserialization.

This is an allowlist approach: only dicts explicitly produced by
`Serializable.to_json()` are treated as LC objects; everything else is escaped if it
could be confused with the LC format.
"""

import json
from typing import Any

from pydantic import BaseModel

from langchain_core.load._validation import _serialize_value
from langchain_core.load.serializable import Serializable, to_json_not_implemented
from langchain_core.messages import AIMessage
from langchain_core.outputs import ChatGeneration


def default(obj: Any) -> Any:
    """Return a default value for an object.

    Args:
        obj: The object to serialize to json if it is a Serializable object.

    Returns:
        A JSON serializable object or a SerializedNotImplemented object.
    """
    if isinstance(obj, Serializable):
        return obj.to_json()
    return to_json_not_implemented(obj)


def _dump_pydantic_models(obj: Any) -> Any:
    """Convert nested Pydantic models to dicts for JSON serialization.

    Handles the special case where a `ChatGeneration` contains an `AIMessage`
    with a parsed Pydantic model in `additional_kwargs["parsed"]`. Since
    Pydantic models aren't directly JSON serializable, this converts them to
    dicts.

    Args:
        obj: The object to process.

    Returns:
        A copy of the object with nested Pydantic models converted to dicts, or
            the original object unchanged if no conversion was needed.
    """
    if (
        isinstance(obj, ChatGeneration)
        and isinstance(obj.message, AIMessage)
// ... (61 more lines)