LangGraph エージェントの可観測性

async function emitGraphInvocation(data) {
  try {
    const delivery = await fetch("https://api.telemetry.sh/log", {
      method: "POST",
      headers: {
        Authorization: process.env.TELEMETRY_API_KEY,
        "Content-Type": "application/json",
      },
      body: JSON.stringify({ table: "agent_graph_invocation", data }),
      signal: AbortSignal.timeout(1000),
    });
    if (!delivery.ok) throw new Error("telemetry_delivery_unconfirmed");
  } catch {
    try { console.warn("Telemetry delivery unconfirmed"); } catch {}
  }
}

async function observedInvoke(graph, input, { threadId, config = {} }) {
  const startedAt = performance.now();
  const outcome = {
    thread_id: threadId,
    invocation_id: crypto.randomUUID(),
    graph_name: "support_agent",
    status: "failed",
    release: process.env.APP_RELEASE,
  };

  try {
    const result = await graph.invoke(input, {
      ...config,
      configurable: { ...config.configurable, thread_id: threadId },
    });
    outcome.status = "returned";
    // Metadata inspection must not replace the graph's result.
    try {
      const paused = Array.isArray(result?.__interrupt__) &&
        result.__interrupt__.length > 0;
      if (paused) outcome.status = "paused";
      if (Array.isArray(result?.messages)) {
        outcome.message_count = result.messages.length;
      }
    } catch {}
    return result;
  } finally {
    outcome.duration_ms = Math.round(performance.now() - startedAt);
    await emitGraphInvocation(outcome);
  }
}

const threadId = crypto.randomUUID(); // Keep this ID when resuming this thread.
const result = await observedInvoke(graph, { messages }, { threadId });