Anthropic uses its own API. OpenAI, xAI Grok, DeepSeek and local models use the OpenAI chat completions format.

Anthropic and OpenAI models are the most reliable at looking things up with tools. A local model, for example with Ollama, keeps everything on your network.

DeepSeek's hosted API stores data in the People's Republic of China, so it stays off until "Allow DeepSeek" is ticked. DeepSeek's open models can run locally instead.