Add interrupt (human-in-the-loop) example (#63)

Author: mtrinell

examples/interrupt/README.md

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+# Interrupt Agent
+
+A simple LangGraph-based agent which expects human input during its operation.
+
+## Getting Started
+
+```bash
+poetry install
+python interrupt/interrupt.py
+```

examples/interrupt/deploy/manifest.json

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+{
+  "metadata": {
+    "ref": {
+      "name": "org.agntcy.interrupt",
+      "version": "0.0.1"
+    },
+    "description": "Agent Connect Protocol Interrupt (Human-In-The-Loop) Example"
+  },
+  "specs": {
+    "input": {
+      "type": "object",
+      "properties": {
+        "input": {
+          "type": "string",
+          "description": "The human input"
+        }
+      }
+    },
+    "output": {
+      "type": "object",
+      "oneOf": [
+        {
+          "properties": {
+            "human_answer": {
+              "type": "string"
+            }
+          },
+          "required": [
+            "human_answer"
+          ]
+        },
+        {
+          "properties": {
+            "ai_answer": {
+              "type": "string"
+            }
+          },
+          "required": [
+            "ai_answer"
+          ]
+        }
+      ]
+    },
+    "config": {
+      "type": "object",
+      "properties": {}
+    },
+    "capabilities": {
+      "threads": false,
+      "interrupts": true,
+      "callbacks": false
+    },
+    "interrupts": []
+  },
+  "dependencies": [],
+  "deployment": {
+    "dependencies": [],
+    "deployment_options": [
+      {
+        "type": "source_code",
+        "name": "src",
+        "url": "github.com/cisco-eti/agent-connect-protocol.git/examples/agents/interrupt",
+        "framework_config": {
+          "framework_type": "langgraph",
+          "graph": "interrupt.interrupt:graph"
+        }
+      }
+    ]
+  }
+}

examples/interrupt/interrupt/interrupt.py

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+import asyncio
+import uuid
+from typing import Optional
+
+from langgraph.checkpoint.memory import MemorySaver
+from langgraph.constants import END, START
+from langgraph.graph import StateGraph
+from langgraph.types import Command, interrupt
+from typing_extensions import TypedDict
+
+
+class State(TypedDict):
+    """The graph state."""
+
+    input: str
+    """The input value of the node."""
+
+    ai_answer: Optional[str]
+    """AI answer"""
+
+    human_answer: Optional[str]
+    """Human value will be updated using an interrupt."""
+
+
+async def node1(state: State):
+    print(f"> Node1 input: {state['input']}")
+    await asyncio.sleep(1)
+    return {"ai_answer": "This is the output of node1"}
+
+
+async def node2(state: State):
+    print(f"> Received input: {state['ai_answer']}")
+    answer = interrupt(
+        # This value will be sent to the client
+        # as part of the interrupt information.
+        {"ai_answer": "What is your age?"}
+    )
+    print(f"> Received an input from the interrupt: {answer}")
+    await asyncio.sleep(2)
+    return {"human_answer": answer}
+
+
+async def node3(state: State):
+    print(f"> Received input: {state['human_answer']}")
+    await asyncio.sleep(3)
+    return {"ai_answer": "This is the output of node3"}
+
+
+builder = StateGraph(State)
+builder.add_node("node1", node1)
+builder.add_node("node2", node2)
+builder.add_node("node3", node3)
+
+builder.add_edge(START, "node1")
+builder.add_edge("node1", "node2")
+builder.add_edge("node2", "node3")
+builder.add_edge("node3", END)
+
+
+# A checkpointer must be enabled for interrupts to work!
+checkpointer = MemorySaver()
+graph = builder.compile(checkpointer=checkpointer)
+
+config = {
+    "configurable": {
+        "thread_id": uuid.uuid4(),
+    }
+}
+
+
+async def run_graph():
+    async for chunk in graph.astream({"input": "something"}, config):
+        print(chunk)
+
+    command = Command(resume=input("Enter the interrupt command: "))
+
+    async for chunk in graph.astream(command, config):
+        print(chunk)
+
+
+if __name__ == "__main__":
+    asyncio.run(run_graph())