Human-in-the-loop (interrupt / resume): README.md

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+# Human‑in‑the‑loop (Interrupt / Resume) – LangGraph Demo
+
+This repository contains a minimal example of a **LangGraph** that pauses execution to ask the user for confirmation via a custom interrupt.  
+The graph demonstrates how to:
+
+* Define a typed state with fields that will be filled by a human.
+* Trigger an interrupt from a node, passing a structured payload (`type`, `question`, `allow_responds`).
+* Handle the interrupt in a loop: display the question in the console (using *questionary*), capture the answer and resume the graph.
+
+---
+
+## 📦 Installation
+
+```bash
+# Create a virtual environment if you wish
+python -m venv .venv
+source .venv/bin/activate   # On Windows use `.venv\Scripts\activate`
+
+# Install dependencies
+pip install langgraph questionary
+```
+
+> **Tip**: If you plan to extend the graph with LLM calls, add `langchain` and an appropriate provider (e.g., `langchain-openai`) to your requirements.
+
+---
+
+## 📁 Project Structure
+
+```text
+.
+├── interrupt_graph.py   # The LangGraph implementation
+└── README.md            # This file
+```
+
+---
+
+## 🚀 Running the Example
+
+The graph is executed in a simple loop that keeps running until the user chooses to stop.  
+Run it with:
+
+```bash
+python interrupt_graph.py
+```
+
+You should see something like:
+
+```
+[Graph] Starting new run...
+[Interrupt] type: confirm
+Question: Уверены, что хотите продолжить?
+Options: approve / reject
+
+Your choice: approve
+[Graph] Resuming after interrupt...
+
+[Graph] Run finished. Final state:
+{'human_value': 'approve', 'foo': None}
+```
+
+If you answer `reject`, the graph will still resume but with a different value.
+
+---
+
+## 📄 Example Usage in Code
+
+```python
+# interrupt_graph.py (excerpt)
+
+from langgraph.types import interrupt
+
+def node_with_interrupt(state: GraphState) -> GraphState:
+    if state.get("human_value") is not None:
+        return state
+
+    payload = {
+        "type": "confirm",
+        "question": "Уверены, что хотите продолжить?",
+        "allow_responds": ["approve", "reject"],
+    }
+    # Pause the graph until a human responds
+    return interrupt(payload)
+```
+
+The main loop in `interrupt_graph.py` handles this payload:
+
+```python
+while True:
+    result = graph.run(state=state, config=config)
+    if isinstance(result, Command):
+        # Show question and get answer
+        choice = questionary.select(
+            result.payload["question"],
+            choices=result.payload["allow_responds"]
+        ).ask()
+        state["human_value"] = choice
+        continue  # resume graph
+    else:
+        break  # finished
+```
+
+---
+
+## 🎯 What You Can Learn
+
+* How to **pause** a LangGraph node and wait for user input.
+* How to structure the interrupt payload so that it can be rendered in any UI (console, web, etc.).
+* The pattern of looping over `graph.run()` until no more `Command` objects are returned.
+
+Feel free to fork this repository and experiment with different interrupt types or add LLM calls to make the graph more complex!