I picked up some more details on Claude 4 from a dive through the Anthropic documentation
The training cut-off date is March 2025! Input limits are still stuck at 200,000 tokens. Unlike 3.7 Sonnet the thinking trace is now summarized by a separate model […]
Anthropic's Hannah Moran finally addressed the elephant in the room at this conference when she subtly dropped "Agents are models using tools in a loop" during the intro to the "Prompting for Agents" workshop https://simonwillison.net/2025/May/22/tools-in-a-loop/
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The training cut-off date is March 2025! Input limits are still stuck at 200,000 tokens. Unlike 3.7 Sonnet the thinking trace is now summarized by a separate model […]