The government of Rio de Janeiro in Brazil has launched an AI model called Rio 3.5 Open 397B to rival models like ChatGPT and Claude. The model, developed by a municipal IT firm IplanRIO, outperformed models like Alibaba's Qwen 3.5 Plus and Deepseek V4 Pro. This comes a day after US banned Anthropic's Claude Mythos and Fable 5 for foreigners.