Simon Willison’s Weblog

llm-ollama 0.9.0. This release of the llm-ollama plugin adds support for schemas, thanks to a PR by Adam Compton.

Ollama provides very robust support for this pattern thanks to their structured outputs feature, which works across all of the models that they support by intercepting the logic that outputs the next token and restricting it to only tokens that would be valid in the context of the provided schema.

With Ollama and llm-ollama installed you can run even run structured schemas against vision prompts for local models. Here's one against Ollama's llama3.2-vision:

llm -m llama3.2-vision:latest \
  'describe images' \
  --schema 'species,description,count int' \
  -a https://static.simonwillison.net/static/2025/two-pelicans.jpg

I got back this:

{
    "species": "Pelicans",
    "description": "The image features a striking brown pelican with its distinctive orange beak, characterized by its large size and impressive wingspan.",
    "count": 1
}

(Actually a bit disappointing, as there are two pelicans and their beaks are brown.)