Simon Willison builds Bluesky bot checker with Opus 5.5

The tool looks for patterns such as rapid‑reply timestamps, lack of original posts, images or links, and the presence of question‑mark characters in replies. Willison notes that the lack of a restrictive API does not stop bots, but it makes detection harder, which motivated the creation of this checker. He references recent LLM releases—Claude Opus 5.5, GPT‑6 Sol, GPT‑6 Luna—and a price‑war context, but the focus remains on the practical bot‑detection script.

Willison’s post is a personal account of building and using the checker, offering a concrete example of how current language models can be applied to platform‑specific moderation challenges.