Simon Willison’s Weblog

Includes new features enabled by LLM 0.32:

• New models: claude-fable-5, claude-sonnet-5, and claude-opus-5. #75, #76
• Added server-side tools for WebSearch, WebFetch, CodeExecution, and AnthropicMCP, available through LLM's -T interface or Python tools=. The previous -o web_search* options have been removed in favor of -T WebSearch. #79
• Upgraded to llm>=0.32. Reasoning, tool calls, tool results, and server-side tool results now stream as typed events. Reasoning for llm CLI prompts now displays to standard error unless you pass --hide-reasoning/-R.
• Simplified extended thinking to thinking and thinking_effort (low, medium, high, xhigh, or max). Claude 5 models think by default; -o thinking 0 disables thinking for Sonnet 5 and Opus 5, while Fable 5 always thinks. -R/--hide-reasoning now omits reasoning from responses and logs. The thinking_budget, thinking_display, and thinking_adaptive options have been removed. #80