Seed 2.1 Pro is ByteDance's flagship agent model, announced at the Volcano Engine conference on June 23-24, 2026. It is a deep-thinking model built for real-world productivity — strong demand understanding, long-horizon planning, and continuous self-repair let it deliver reliable end-to-end results across various domains. Available through the Volcano Engine API and the Coze ecosystem with a 256K-token context window. The model accepts text and image input and powers the Doubao consumer chatbot in China.