Deep Dive into Open Agent SDK (Part 6): Multi-LLM Providers and Runtime Controls

An Agent shouldn't be locked to a single LLM provider. Different tasks suit different models — simple questions use cheap models, complex reasoning uses expensive ones, and some scenarios even require local models. Runtime needs change too: users might want deeper thinking mid-session, discover the budget is running low and need to downgrade, or switch to a local model to save money. Open Agent SDK's approach: define a unified LLMClient protocol, with Anthropic and OpenAI-compatible providers ea