Together AI

Together AI provides cloud infrastructure for developers and enterprises to train, customize and run open AI models. Together Inference offers serverless access, asynchronous batch processing and dedicated model deployments. Its fine-tuning service lets teams adapt models without managing training infrastructure, while Accelerated Compute supplies GPU clusters for larger workloads. The platform also includes managed storage and code sandboxes for AI applications and agents.

Founded in 2022 by Vipul Ved Prakash, Ce Zhang, Percy Liang and Christopher Ré, Together AI is led by Prakash as CEO and Zhang as CTO. Tri Dao joined as chief scientist in 2023 and is now also listed as a founder. Its research includes Dao and collaborators’ FlashAttention, which accelerates exact attention and reduces memory use by reorganizing computation into blocks. FlashAttention-2 improves GPU parallelism and work partitioning to make model training and inference more efficient.

The business serves both application builders and teams developing their own models. In July 2026, the company reported over one million developers and thousands of paying customers, including Cursor, Cognition and Decagon. It also announced an $800 million Series C at an $8.3 billion post-money valuation. Customers can customize models with proprietary datasets, then host the resulting models on Together or download them.