Meta Tests GPT-5.5 With 'Watermelon' Model

Meta's Muse Spark model launched in April to a shrug. Industry read: usable, but nowhere near frontier. Three months on, chief AI officer Alexandr Wang says the follow-up has closed that gap entirely.

The model goes by the internal codename "Watermelon," and Wang is telling people it performs on par with OpenAI's GPT-5.5. That's a big jump for a company whose last public release drew the verdict "not great, but back in the game." Wang has also teased an upcoming coding model he compares to Anthropic's Opus tier, Anthropic's top-of-line coding product and a benchmark rivals treat as the one to beat.

None of this happens in a vacuum. OpenAI isn't pausing development while Meta trains its next release, and GPT-5.5 itself won't be the finish line for long. But Meta has sunk roughly $145 billion into its AI buildout, and until now the return on that spending has been hard to see in the actual products. Wang's claims, if they hold up once Watermelon ships, would mark the first sign that the money is translating into something the rest of the field has to reckon with.