Together AI is a cloud platform for running, training, and fine-tuning open and open-weight AI models. Developers can access hundreds of models through a unified API, run inference at competitive prices, and use the platform's infrastructure for fine-tuning and dedicated enterprise deployments, positioning Together as an open-ecosystem alternative to closed model providers.
The platform's thesis is that open models, paired with optimized infrastructure, can deliver strong performance at substantially lower cost while giving teams control over models and data. Together combines an inference API, training and fine-tuning tooling, and GPU-cloud capacity to support the full lifecycle from experimentation to production.
Together AI was founded in 2022 with a research-heavy founding team. CEO Vipul Ved Prakash leads the company alongside co-founders that include prominent AI researchers such as Percy Liang, Chris Re, Ce Zhang, and Tri Dao, giving Together credibility in both systems and model research, including efficiency techniques used widely across the field.
The company is strongly capitalized. In February 2025 it announced a $305 million Series B led by General Catalyst and co-led by Prosperity7, at a roughly $3.3 billion valuation, with participation from NVIDIA, Kleiner Perkins, Salesforce Ventures, and others, building on prior rounds and bringing substantial cumulative funding.
Together reports broad developer adoption, powering large numbers of AI applications with its API and acceleration cloud, and offers enterprise deployments for organizations that need scale, performance, and control over open models.
The platform is best for developers and enterprises that want to build on open models with cost efficiency, fine-tuning flexibility, and data control. Teams committed to a single proprietary frontier model, or those wanting a fully managed end-user product rather than infrastructure, may find it less of a fit.