Simon Willison / Simon Willison's Weblog:

A Claude user gets Claude 4.5 Opus to generate a 14K-token document that Claude calls its “Soul overview”; an Anthropic employee confirms the doc's validity  —  This appeared to be a document that, rather than being added to the system prompt, was instead used to train the personality of the model during the training run.

Simon Willison / Simon Willison's Weblog:

A Claude user gets Claude 4.5 Opus to generate a 14K-token document that Claude calls its “Soul overview”; an Anthropic employee confirms the doc's validity  —  This appeared to be a document that, rather than being added to the system prompt, was instead used to train the personality of the model during the training run.

Source: TechMeme
Source Link: http://www.techmeme.com/251202/p24#a251202p24