Together AI

Together AI is an AI infrastructure company founded in 2022, providing a cloud platform for running, fine-tuning, and building with open-source AI models. In July 2026 it raised an $800 million Series C led by Aramco Ventures, with NVIDIA, Vista Equity Partners, and General Catalyst participating — cementing its position as one of the leading alternatives to proprietary model APIs.

Together's platform offers fast inference for popular open-weight models (Llama, DeepSeek, Mistral, Qwen, and many others), fine-tuning services for customizing models on proprietary data, and training infrastructure for organizations building their own models. Its inference speeds are competitive with the fastest available while offering a much broader selection of models — positioning it as the infrastructure layer for teams that want open models without managing GPU fleets directly.

The company competes with Baseten, Replicate, and cloud-provider endpoints, while investing in efficient-training research (sparse attention, mixture-of-experts, and data-efficient methods). Its trajectory tracks a broader market shift: as enterprises move more inference onto cheaper open models, Together has positioned itself to capture that demand, and plans to scale its compute footprint substantially over the coming years.