Together AI raises $305m Series B
General Catalyst and Prosperity7 led the round at a $3.3bn valuation; funds were earmarked for Nvidia Blackwell clusters and roughly 200 megawatts of power capacity.
- Money & business
- Open weights & ecosystem
- Minor
Together AI, a cloud platform for running and fine-tuning open-weight models, raised $305 million in a Series B round led by General Catalyst and Prosperity7, valuing the company at $3.3 billion. Salesforce Ventures, Nvidia and Kleiner Perkins were among the other participants.
The company positioned itself as infrastructure for the open-model ecosystem rather than as a model developer: its “AI Acceleration Cloud” offered inference, training and fine-tuning across more than 200 open-source models, along with agentic-workflow and synthetic-data tools, and it said the platform served more than 450,000 developers. Together AI said the funds would go toward deploying clusters of Nvidia’s newer Blackwell GPUs across North American data centres and securing roughly 200 megawatts of power capacity, alongside continued research into inference efficiency.
The round came a month after DeepSeek’s R1 release had renewed attention on open-weight models as a cost-competitive alternative to closed frontier labs, and it placed Together AI — alongside other inference-focused providers — among a set of infrastructure companies raising large rounds to serve that demand rather than compete on training frontier models directly.