Simon Willison’s Weblog
OpenAI released their new Jev-style Decisions API , as previously announced at last week's DevDay.
Since I already have an llm-typesafe plugin for talking to Jev, I had GPT-6 Astra read the new OpenAI API documentation and build an llm-openai-decisions plugin inspired by llm-typesafe .
Unlike Jev, the new gpt-6-luna decision model supports image input in addition to text. Both models charge for input it and not for output: OpenAI's is 10 cents per million input tokens, Jev's is 4.2 cents per million.
Otherwise the API shape is very similar to Jev, at least conceptually. Jev supports three question types for yes/no, choices, or scores. OpenAI Decisions supports the same three types.
llm install llm-openai-decisions
Here's an example query against an image attachment:
llm -m openai-decisions/gpt-6-luna \ -a https://static.simonwillison.net/static/2025/two-pelicans.jpg \ -s ' Does this image contain any mammals? '
{ "type" : " predicate " , "name" : " evaluation " , "probability" : 0.0 }
Consult the README for full details of how to run the other types of questions.
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