RunnableConfigurableFields Class — langchain Architecture

Source Code

libs/core/langchain_core/runnables/configurable.py lines 318–459

class RunnableConfigurableFields(DynamicRunnable[Input, Output]):
    """`Runnable` that can be dynamically configured.

    A `RunnableConfigurableFields` should be initiated using the
    `configurable_fields` method of a `Runnable`.

    Here is an example of using a `RunnableConfigurableFields` with LLMs:

        ```python
        from langchain_core.prompts import PromptTemplate
        from langchain_core.runnables import ConfigurableField
        from langchain_openai import ChatOpenAI

        model = ChatOpenAI(temperature=0).configurable_fields(
            temperature=ConfigurableField(
                id="temperature",
                name="LLM Temperature",
                description="The temperature of the LLM",
            )
        )
        # This creates a RunnableConfigurableFields for a chat model.

        # When invoking the created RunnableSequence, you can pass in the
        # value for your ConfigurableField's id which in this case
        # will be change in temperature

        prompt = PromptTemplate.from_template("Pick a random number above {x}")
        chain = prompt | model

        chain.invoke({"x": 0})
        chain.invoke({"x": 0}, config={"configurable": {"temperature": 0.9}})
        ```

    Here is an example of using a `RunnableConfigurableFields` with `HubRunnables`:

        ```python
        from langchain_core.prompts import PromptTemplate
        from langchain_core.runnables import ConfigurableField
        from langchain_openai import ChatOpenAI
        from langchain.runnables.hub import HubRunnable

        prompt = HubRunnable("rlm/rag-prompt").configurable_fields(
            owner_repo_commit=ConfigurableField(
                id="hub_commit",
                name="Hub Commit",
                description="The Hub commit to pull from",
            )
        )

        prompt.invoke({"question": "foo", "context": "bar"})

        # Invoking prompt with `with_config` method

        prompt.invoke(
            {"question": "foo", "context": "bar"},
            config={"configurable": {"hub_commit": "rlm/rag-prompt-llama"}},
        )
        ```
    """

    fields: dict[str, AnyConfigurableField]
    """The configurable fields to use."""

    @property
    def config_specs(self) -> list[ConfigurableFieldSpec]:
        """Get the configuration specs for the `RunnableConfigurableFields`.

        Returns:
            The configuration specs.
        """
        config_specs = []

        default_fields = type(self.default).model_fields
        for field_name, spec in self.fields.items():
            if isinstance(spec, ConfigurableField):
                config_specs.append(
                    ConfigurableFieldSpec(
                        id=spec.id,
                        name=spec.name,
                        description=spec.description
                        or default_fields[field_name].description,