As of today, Ploy’s agent runs on GPT-5.6 Sol, the flagship tier of the model family OpenAI released this morning. For months, we couldn’t find a model that challenges Claude Opus given our incredibly high bar for quality. That changed with GPT 5.6 Sol. After running it head-to-head against Claude Opus, we’ve made GPT 5.6 Sol the default model powering every Ploy workspace. That’s a bigger switch than it sounds. Ploy’s agent builds and edits real marketing websites. It plans a page, reads the codebase, writes components, generates imagery, screenshots its own work, and decides when it’s done. That job description sets a very high bar for a model, and we test every frontier release against it. For the four months Opus held the default slot (first Opus 4.7, then 4.8), nothing we tested beat it. GPT-5.6 is the first model that did. Not that the first eval run was perfect. It had real failure modes, which we’ll show you.…