Article · Simon Willison ·
In a comment on Hacker News Drew reveals the Opus 5.5 prompts he used to build this system:
A tool or model opens in the Heidelberg AI Curriculum: what it does, what it costs, how to start. A repo opens on GitHub.
ArticleSimon Willison
OpenAI has launched an API credits benefit for eligible ChatGPT subscriptions, mirroring a similar benefit Anthropic announced earlier for its Max and Team plans. OpenAI subscribers to its $100, $200, or $500 per month plans now receive the equivalent quantity of expiring credits to apply to one of their API organizations.
ArticleSimon Willison
Simon Willison's blog post shares a piece by Jacob Sansbury describing how his company is building Spawn, a massively multiplayer gaming environment in which players use prompts to an in-game agent called Savi to modify the game world. Willison reports trying it on his phone and being able to prompt a castle into existence, then a dragon, then ride the dragon around the castle, calling the work an exploration of the bleeding edge of agentic engineering against frontier models.
ArticleSimon Willison
Ben Hylak is quoted saying that every product he uses should be a headless MCP that feeds into an agent, so he never has to think about anything underneath, except his own product, which keeps a UI that customers love.
ArticleSimon Willison
In general, LLM performance is incredibly multidimensional. There's no guarantee of a fixed ordering where the model that is best at math is also the model that's best at jokes. Despite that complexity, much of the variation in performance is explained by just a single variable: model size.