Arcee AI

Arcee AI builds Trinity open-weight foundation models and tools for developers and enterprises to customize language models. Its work has expanded from adapting existing models for specific domains to training its own foundation models. Trinity spans smaller Nano and Mini models through Large and Large-Thinking, with hosted API access and downloadable weights. Developers can inspect, post-train, distill and host the models themselves. The family uses OpenMDW-1.1, permitting modification and commercial deployment without a separate commercial license.

Founded in 2023, Arcee’s co-founders are CEO Mark McQuade, Brian Benedict and Jacob Solawetz. McQuade and Benedict previously worked at Hugging Face; Solawetz came from computer-vision company Roboflow. Its engineering contributions include MergeKit, an open-source library that combines model parameters to bring together capabilities from different checkpoints without additional training. Its Spectrum approach selectively trains useful layer modules while freezing others, reducing the amount of a model that needs updating during customization.

In 2026, the company reported that Trinity-Large-Preview served 3.37 trillion tokens through OpenRouter in its first two months. By June, it reported 30 employees, including 14 in research, and more than 200 models on Hugging Face with millions of downloads. That year, Arcee entered a multi-million-dollar partnership making Hugging Face the exclusive home for its models, datasets and agent traces.