LangGraph con TypeScript: Agentes de IA Deterministas en Producción

1import { StateGraph, Annotation, END, START } from "@langchain/langgraph";
2import { MemorySaver } from "@langchain/langgraph";
3import { BaseMessage, HumanMessage } from "@langchain/core/messages";
4
5 State Annotation con Reducers deterministas en TS
6const AgentState = Annotation.Root({
7  messages: Annotation<BaseMessage[]>({
8    value: (x, y) => x.concat(y),
9    default: () => [],
10  }),
11  context: Annotation<Record<string, unknown>>({
12    value: (x, y) => ({ ...x, ...y }),
13    default: () => ({}),
14  }),
15  isApproved: Annotation<boolean>({
16    value: (_, y) => y,
17    default: () => false,
18  })
19});
20
21 Inicialización de StateGraph tipado
22const builder = new StateGraph(AgentState)
23  .addNode("supervisorNode", async (state) => {
24     Evaluación de intenciones sin wrappers frágiles
25    return { context: { step: "supervised" } };
26  })
27  .addNode("executeAction", async (state) => {
28    return { messages: [new HumanMessage("Ejecutando acción con side-effects")] };
29  })
30  .addEdge(START, "supervisorNode")
31  .addConditionalEdges("supervisorNode", (state) => {
32    return state.isApproved ? "executeAction" : END;
33  })
34  .addEdge("executeAction", END);
35
36 Checkpointer para persistencia local & threads
37export const graph = builder.compile({
38  checkpointer: new MemorySaver(),
39});