From simple Q&A bots to advanced AI agents, chatbot technology is evolving fast. With the right frameworks, APIs, and design choices, you can create intelligent, scalable, and cost-effective bots.

背景OpenRouter 排行榜上正在发生一场换代：Hermes Agent 增速 +204%，Top Coding Agents 排第一，Top Productivity 排第二。上线不到半年，GitHub 从 0 到 106k+ ...

Async FastAPI API that acts as an autonomous customer support agent: natural language → ReAct loop + tool use (order lookup, cancel, list) → PostgreSQL via SQLAlchemy → natural language response.

finance_tracker/ ├── app/ │ ├── main.py # FastAPI app, middleware, router registration │ ├── config.py # Settings via pydantic-settings (.env support) │ ├── database.py # SQLAlchemy engine, session, ...