Together AI has closed an $800 million Series C at an $8.3 billion post-money valuation, one of the largest AI infrastructure rounds of 2026. Aramco Ventures led the financing, which more than doubles the company's $3.3 billion valuation from early 2025 and gives the open-source AI cloud provider fresh capital to expand its training and inference platform.
A Heavyweight Syndicate Bets on Open Models
The round drew a notably strategic investor list: Vista Equity Partners, General Catalyst, Emergence Capital, NVIDIA, Salesforce Ventures, March Capital, Pegatron Ventures and SentinelOne's S Ventures all participated alongside Aramco Ventures. The company says annual bookings crossed $1.15 billion last quarter, with thousands of paying customers including Cursor, Cognition, Decagon, ElevenLabs and Suno. Beyond the equity, Together AI has secured commitments for more than 500 megawatts of compute capacity to be capitalized independently by investors.
Why the Money Is Flowing to AI's Plumbing
Together AI's platform lets enterprises train, fine-tune and run open-source models such as DeepSeek, MiniMax and Kimi at lower cost than closed alternatives. CEO Vipul Ved Prakash, who co-founded the company with Stanford professor Percy Liang and University of Chicago professor Ce Zhang, argues AI's future belongs to "millions of developers and businesses" rather than a few large cloud vendors. Aramco's lead position underscores how energy and infrastructure players want a direct stake in computational supply, a theme also visible in Baseten's $1.5 billion Series F for AI inference.
What It Means for the Open-Source AI Race
The financing lands amid intense competition between proprietary frontier labs and open-model ecosystems. As OpenAI previews GPT-5.6 and enterprises weigh cost against capability, Together AI is positioning itself as the neutral infrastructure layer for open weights. The round also extends 2026's streak of mega-financings across the AI stack, from X Square Robot's $2.8 billion Series C in physical AI to record Q1 venture totals. Together AI says the new capital will fund low-cost inference, expanded GPU capacity and enterprise tooling through 2027.
Reporting based on coverage from TechCrunch and Business Wire.