feat: init project

app/controller/add_langgraph_route.py

@@ -0,0 +1,69 @@
+import random
+from operator import add
+from typing import TypedDict, Annotated, List
+
+from fastapi import FastAPI
+from langgraph.checkpoint.postgres.aio import AsyncPostgresSaver
+from langgraph.constants import START, END
+from langgraph.graph import StateGraph
+
+from app.utils.postgres_checkpointer import AsyncPostgresSaverDep
+
+
+def add_langgraph_route(app: FastAPI):
+  @app.get("/langgraph/invoke")
+  async def langgraph_invoke(thread_id: str, checkpointer: AsyncPostgresSaverDep):
+    print("checkpointer", checkpointer)
+    graph = create_graph(checkpointer)
+    config = {"configurable": {"thread_id": thread_id}}
+    graph_state = await graph.ainvoke({"name_list": [f"initial:{thread_id}"]}, config=config)
+    return graph_state
+
+  @app.get("/langgraph/get_state")
+  async def langgraph_get_state(thread_id: str, checkpointer: AsyncPostgresSaverDep):
+    graph = create_graph(checkpointer)
+    config = {"configurable": {"thread_id": thread_id}}
+    graph_state = await graph.aget_state(config)
+    return graph_state.values
+
+  @app.get("/langgraph/get_state_snapshot")
+  async def langgraph_get_state_snapshot(thread_id: str, checkpointer: AsyncPostgresSaverDep):
+    graph = create_graph(checkpointer)
+    config = {"configurable": {"thread_id": thread_id}}
+    graph_state = await graph.aget_state(config)
+    return graph_state
+
+
+def create_graph(checkpointer: AsyncPostgresSaver):
+  class StateSchema(TypedDict):
+    name_list: Annotated[List[str], add]
+
+  builder = StateGraph(StateSchema)
+
+  def node_1(state):
+    random_int = random.randint(0, 100)
+    print(["🧠节点执行", "node_1", random_int])
+    return {"name_list": [f"node_1:{random_int}"]}
+
+  def node_2(state):
+    random_int = random.randint(100, 200)
+    print(["🧠节点执行", "node_2", random_int])
+    return {"name_list": [f"node_2:{random_int}"]}
+
+  def node_3(state):
+    random_int = random.randint(300, 400)
+    print(["🧠节点执行", "node_3", random_int])
+    return {"name_list": [f"node_3:{random_int}"]}
+
+  builder.add_node(node_1)
+  builder.add_node(node_2)
+  builder.add_node(node_3)
+
+  builder.add_edge(START, 'node_1')
+  builder.add_edge('node_1', 'node_2')
+  builder.add_edge('node_2', 'node_3')
+  builder.add_edge('node_3', END)
+
+  graph = builder.compile(checkpointer=checkpointer)
+
+  return graph