River AI, the Palo Alto startup founded by xAI co-founder Igor Babuschkin, has raised $1.1 billion in a seed and Series A round led by General Catalyst and AMP PBC, with participation from Nvidia, AMD Ventures, Y Combinator and Temasek. The company emerged from stealth in June — making the round one of the largest ever for a company that is barely two months old.
Babuschkin, whose résumé includes stints at DeepMind and OpenAI before co-founding xAI, wants to reinvent AI from first principles, starting with how models are trained. Instead of building ever-larger models designed to replace human workers, River aims to turn agents into personally trainable assistants.
"Capable agents will be a normal part of everyday life. Less like the assistants you call on today when you need a task done, more like guardian angels: quietly present, on your side, helping with what actually matters to you," Babuschkin wrote in his launch blog. "They will know you well, and they will be yours, not someone else's."
To get there, he argues, the stack has to be rebuilt end-to-end — training, models, the product layer, and new hardware that lets personal AI live close to the user. River's first product is an API billed per million tokens that lets developers fine-tune open models using reinforcement learning (RL) and low-rank adaptation (LoRA). The pitch is positioned as an antidote to prompt engineering: "Prompting steers a model you don't own and can't improve. River lets you train open models into ones that are truly yours — and serve them like any other endpoint."
The company claims 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.
River's bet comes as enterprises increasingly want to control their AI destiny with a mix of models, including open-weight ones, and as the idea of locally running personal agents gathers momentum. Whether the technology delivers remains to be seen — but the startup now has a war chest of cash to try.
