base.py — langchain Source File

Source Code

"""Factory functions for embeddings."""

import functools
import importlib
from collections.abc import Callable
from typing import Any

from langchain_core.embeddings import Embeddings


def _call(cls: type[Embeddings], **kwargs: Any) -> Embeddings:
    return cls(**kwargs)


_BUILTIN_PROVIDERS: dict[str, tuple[str, str, Callable[..., Embeddings]]] = {
    "azure_openai": ("langchain_openai", "AzureOpenAIEmbeddings", _call),
    "bedrock": (
        "langchain_aws",
        "BedrockEmbeddings",
        lambda cls, model, **kwargs: cls(model_id=model, **kwargs),
    ),
    "cohere": ("langchain_cohere", "CohereEmbeddings", _call),
    "google_genai": ("langchain_google_genai", "GoogleGenerativeAIEmbeddings", _call),
    "google_vertexai": ("langchain_google_vertexai", "VertexAIEmbeddings", _call),
    "huggingface": (
        "langchain_huggingface",
        "HuggingFaceEmbeddings",
        lambda cls, model, **kwargs: cls(model_name=model, **kwargs),
    ),
    "mistralai": ("langchain_mistralai", "MistralAIEmbeddings", _call),
    "ollama": ("langchain_ollama", "OllamaEmbeddings", _call),
    "openai": ("langchain_openai", "OpenAIEmbeddings", _call),
}
"""Registry mapping provider names to their import configuration.

Each entry maps a provider key to a tuple of:

- `module_path`: The Python module path containing the embeddings class.
- `class_name`: The name of the embeddings class to import.
- `creator_func`: A callable that instantiates the class with provided kwargs.

!!! note

    This dict is not exhaustive of all providers supported by LangChain, but is
    meant to cover the most popular ones and serve as a template for adding more
    providers in the future. If a provider is not in this dict, it can still be
    used with `init_chat_model` as long as its integration package is installed,
    but the provider key will not be inferred from the model name and must be
    specified explicitly via the `model_provider` parameter.

    Refer to the LangChain [integration documentation](https://docs.langchain.com/oss/python/integrations/providers/overview)
    for a full list of supported providers and their corresponding packages.
"""


@functools.lru_cache(maxsize=len(_BUILTIN_PROVIDERS))
def _get_embeddings_class_creator(provider: str) -> Callable[..., Embeddings]:
    """Return a factory function that creates an embeddings model for the given provider.

    This function is cached to avoid repeated module imports.
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