River AI, an AI startup founded by xAI co-founder Igor Babuschkin, has secured $1.1 billion in funding in a seed/Series A round led by General Catalyst and AMP PBC, with participation from Nvidia, AMD Ventures, Y Combinator, and Temasek. AMP PBC is an AI-focused investment firm founded in 2026 by former Andreessen Horowitz general partner Anjney Midha. River came out of stealth in June with a mission to reinvent AI from scratch, beginning with how models are trained, to turn agents into personally trainable assistants rather than human worker replacements. Babuschkin wrote that the stack must be rebuilt end to end, including training, models, the product layer, and new hardware. River already offers an API, billed per 1 million tokens, with rates dependent on the open model used, allowing developers to use reinforcement learning and low-rank adaptation fine-tuning. The company says any enterprise can complete a complex reinforcement learning run in 15 to 20 minutes with no infrastructure team required, at two to four times the cost savings relative to closed-source alternatives. The bigger vision is that everyone will have their own agents, trained by themselves, and working on their behalf.