get_graph() — langchain Function Reference

Architecture documentation for the get_graph() function in base.py from the langchain codebase.

Function python LangChainCore Runnables calls 1

Entity Profile

LangChainCore→ Runnables→ get_graph() — langchain Function Reference

Dependency Diagram

graph TD
  92646703_74f4_de33_6f1d_887ee39c4db1["get_graph()"]
  c4bf8d59_69f9_f8e5_efba_837c20df2360["RunnableSequence"]
  92646703_74f4_de33_6f1d_887ee39c4db1 -->|defined in| c4bf8d59_69f9_f8e5_efba_837c20df2360
  dd68934b_b24b_922a_dfc2_d96ad2d88349["get_graph()"]
  92646703_74f4_de33_6f1d_887ee39c4db1 -->|calls| dd68934b_b24b_922a_dfc2_d96ad2d88349
  style 92646703_74f4_de33_6f1d_887ee39c4db1 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

libs/core/langchain_core/runnables/base.py lines 3036–3067

    def get_graph(self, config: RunnableConfig | None = None) -> Graph:
        """Get the graph representation of the `Runnable`.

        Args:
            config: The config to use.

        Returns:
            The graph representation of the `Runnable`.

        Raises:
            ValueError: If a `Runnable` has no first or last node.

        """
        # Import locally to prevent circular import
        from langchain_core.runnables.graph import Graph  # noqa: PLC0415

        graph = Graph()
        for step in self.steps:
            current_last_node = graph.last_node()
            step_graph = step.get_graph(config)
            if step is not self.first:
                step_graph.trim_first_node()
            if step is not self.last:
                step_graph.trim_last_node()
            step_first_node, _ = graph.extend(step_graph)
            if not step_first_node:
                msg = f"Runnable {step} has no first node"
                raise ValueError(msg)
            if current_last_node:
                graph.add_edge(current_last_node, step_first_node)

        return graph