add_node() — langchain Function Reference

Architecture documentation for the add_node() function in graph.py from the langchain codebase.

Function python LangChainCore Runnables calls 2

Entity Profile

LangChainCore→ Runnables→ add_node() — langchain Function Reference

Dependency Diagram

graph TD
  5bdca968_0e0c_d6c2_7bf4_f1990e3d1d78["add_node()"]
  646f3bb5_a594_563e_cfbf_e18bdc9efb90["Graph"]
  5bdca968_0e0c_d6c2_7bf4_f1990e3d1d78 -->|defined in| 646f3bb5_a594_563e_cfbf_e18bdc9efb90
  417755a5_d458_ad2e_a8b0_7b8e1dcb0c46["next_id()"]
  5bdca968_0e0c_d6c2_7bf4_f1990e3d1d78 -->|calls| 417755a5_d458_ad2e_a8b0_7b8e1dcb0c46
  e36afb73_0117_69fe_01c8_c476692e8baa["node_data_str()"]
  5bdca968_0e0c_d6c2_7bf4_f1990e3d1d78 -->|calls| e36afb73_0117_69fe_01c8_c476692e8baa
  style 5bdca968_0e0c_d6c2_7bf4_f1990e3d1d78 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

libs/core/langchain_core/runnables/graph.py lines 312–338

    def add_node(
        self,
        data: type[BaseModel] | RunnableType | None,
        id: str | None = None,
        *,
        metadata: dict[str, Any] | None = None,
    ) -> Node:
        """Add a node to the graph and return it.

        Args:
            data: The data of the node.
            id: The id of the node.
            metadata: Optional metadata for the node.

        Returns:
            The node that was added to the graph.

        Raises:
            ValueError: If a node with the same id already exists.
        """
        if id is not None and id in self.nodes:
            msg = f"Node with id {id} already exists"
            raise ValueError(msg)
        id_ = id or self.next_id()
        node = Node(id=id_, data=data, metadata=metadata, name=node_data_str(id_, data))
        self.nodes[node.id] = node
        return node