mapping.py — langchain Source File

Source Code

"""Serialization mapping.

This file contains a mapping between the `lc_namespace` path for a given
subclass that implements from `Serializable` to the namespace
where that class is actually located.

This mapping helps maintain the ability to serialize and deserialize
well-known LangChain objects even if they are moved around in the codebase
across different LangChain versions.

For example, the code for the `AIMessage` class is located in
`langchain_core.messages.ai.AIMessage`. This message is associated with the
`lc_namespace` of `["langchain", "schema", "messages", "AIMessage"]`,
because this code was originally in `langchain.schema.messages.AIMessage`.

The mapping allows us to deserialize an `AIMessage` created with an older
version of LangChain where the code was in a different location.
"""

# First value is the value that it is serialized as
# Second value is the path to load it from
SERIALIZABLE_MAPPING: dict[tuple[str, ...], tuple[str, ...]] = {
    ("langchain", "schema", "messages", "AIMessage"): (
        "langchain_core",
        "messages",
        "ai",
        "AIMessage",
    ),
    ("langchain", "schema", "messages", "AIMessageChunk"): (
        "langchain_core",
        "messages",
        "ai",
        "AIMessageChunk",
    ),
    ("langchain", "schema", "messages", "BaseMessage"): (
        "langchain_core",
        "messages",
        "base",
        "BaseMessage",
    ),
    ("langchain", "schema", "messages", "BaseMessageChunk"): (
        "langchain_core",
        "messages",
        "base",
        "BaseMessageChunk",
    ),
    ("langchain", "schema", "messages", "ChatMessage"): (
        "langchain_core",
        "messages",
        "chat",
        "ChatMessage",
    ),
    ("langchain", "schema", "messages", "FunctionMessage"): (
        "langchain_core",
        "messages",
        "function",
        "FunctionMessage",
    ),
    ("langchain", "schema", "messages", "HumanMessage"): (
        "langchain_core",
// ... (998 more lines)