连接 Embassy — Downcity City SDK Docs

import { Embassy } from "@downcity/federation";

const embassy = new Embassy({
  federation_url: "https://fed.example.com",
  user_token: "ub_xxx",
});

const catalog = await embassy.user.ai.catalog();
const model = catalog.get("gpt-5.4");
if (!model) throw new Error("model not found");

const result = await embassy.user.ai.text({
  model,
  prompt: "写一段欢迎语",
});

自定义或官方 Service 使用 embassy.user.service(name)。Provider Key、模型路由和 Usage 记账都留在 Federation 内部。