LangGraph
LangGraph is an open-source Python library from the LangChain team for building stateful, multi-actor LLM applications as graphs. It defines an explicit state schema, nodes that read and write that state, edges that route based on state inspection, and built-in support for persistence (checkpointers), human-in-the-loop interruption, and streaming. LangGraph is used standalone or alongside LangChain. It trades the simplicity of a single prompt for explicit control over routing and state, which becomes a gain when the workflow has more than one decision point and the implicit prompt-chained alternative starts hiding the routing logic inside model instructions.
Example
A customer-support graph with nodes for triage, retrieval, response, and escalation — with conditional edges that send the conversation to escalation when the model's confidence drops or the user explicitly asks for a human. The state schema names every field every node reads or writes, so debugging traces back to a single typed object rather than a hidden chain of prompt instructions strung across multiple models.
Put this into practice
Build polished, copy-ready prompts in under 60 seconds with SurePrompts.
Try SurePrompts