General Catalyst leads $1.1B round into 2-month-old River AI

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, backer of companies like Black Forest Labs, Mistral AI, LMArena, and OpenRouter. River came out of stealth in June with a mission to reinvent AI from scratch, beginning with how models are trained, aiming to turn agents into personally trainable assistants rather than human worker replacements. Babuschkin, whose resume includes roles at DeepMind and OpenAI, envisions agents as 'guardian angels' that are personally owned and tailored. River already offers an API that allows developers to use reinforcement learning (RL) and low-rank adaptation (LoRA) fine-tuning on open models, billing per 1 million tokens. The company claims that any enterprise can complete a complex reinforcement learning run in 15 to 20 minutes with no infrastructure team and at two to four times the cost savings relative to closed-source alternatives. This investment comes at a time when enterprises are seeking control over their AI models, and the bigger vision is that everyone will have their own agents trained by themselves.