River AI has raised $1.1 billion in funding led by General Catalyst and AMP PBC to build a full-stack artificial intelligence platform focused on open models, customization, and personal AI. The round also included strategic investments from NVIDIA and AMD Ventures, with additional participation from Y Combinator and Temasek.
River AI was founded by Igor Babuschkin, a co-founder of xAI who previously worked on generative modeling and reinforcement learning at Google DeepMind and led large-scale training efforts at OpenAI.
The company is developing infrastructure that enables developers and enterprises to train, fine-tune, deploy, and control their own AI models without needing a dedicated infrastructure team or specialized hardware.
River said its API can complete complex reinforcement learning training runs in approximately 15 to 20 minutes while delivering costs that are two to four times lower than closed-source alternatives.
The platform supports LoRA fine-tuning and reinforcement learning for frontier open-weight models.
River handles underlying infrastructure requirements including weight transfers, sampling-training consistency and elastic compute, allowing developers to focus on improving model performance instead of managing GPU infrastructure.
Models trained through the platform can be deployed directly into production.
River also uses token-based metering for training and inference, which is intended to prevent customers from paying for unused GPU capacity.
The company is building a broader integrated technology stack that includes hardware intended to bring personal AI closer to users, training infrastructure designed to make fine-tuning accessible to developers, and products centered on personalization and continual learning.
River’s broader thesis is that AI development will increasingly move away from relying solely on general-purpose models trained for billions of users toward customized models built around the requirements of individual companies and eventually individual people.
For enterprises, the company wants to make it easier to create AI models trained on proprietary data and tailored to specific workflows while allowing organizations to retain greater control over those models.
River plans to use the $1.1 billion financing to accelerate development of this open AI stack and advance its longer-term goal of enabling personalized, continually improving AI.
Babuschkin’s founding team includes engineers with experience at xAI and Tesla across deep learning, reinforcement learning and other parts of the AI technology stack.
General Catalyst said the growth of open-weight AI models is strategically important alongside continued development of closed frontier models.
The investment firm also sees River’s approach as addressing the gap between the capabilities of advanced AI and the customized systems most enterprises are currently able to deploy.
River is headquartered in Palo Alto, California.
KEY QUOTES:
“The way AI is built today is not how it will be built in the future. AI should be open, freely available, and affordable. It should feel like it is working for the person using it, not the lab that trained it. We started River to allow people and companies to own their intelligence.”
Igor Babuschkin, Co-Founder and CEO of River AI
“American leadership in AI urgently requires leadership in open weight models, while maintaining a lead in closed frontier models. Igor and the River AI team have the experience to make this happen, and we view their agenda as a priority for American resilience.”
“The core philosophy of putting ownership of intelligence in the hands of the people using it will prove to be on the right side of history for the open weight ecosystem.”
Hemant Taneja, CEO of General Catalyst
“There is a gap between what AI can do and what most companies actually experience. Until now, companies have lacked a cost-efficient way to train, tune, and own custom AI models. River closes this gap, helping any company build models on their own data, tailored to how they actually work.”
Marc Bhargava, Managing Director at General Catalyst
