H Company releases Holo4, open-weight computer-use agent models that operate interfaces, write code and call MCP/APIs with one model
H Company released the Holo4 agentic models in 27B dense and 35B-A3B mixture-of-experts sizes, which complete tasks by clicking and typing, writing and running code, or calling MCP and API tools; the models are on the H Models API and the weights are public on Hugging Face.
In a Hugging Face blog post, H Company introduced Holo4, its new series of agentic models in two sizes, a 27B dense model and a 35B-A3B mixture-of-experts model, and also released Holotron4 Nano, a small model built on NVIDIA’s Nemotron 3 Nano Omni.
The company says most agentic models are trained for one interface only: GUI-focused models are blind without a screen, while models that prefer tool calling are stuck in front of software with no API. Holo4 chooses whether to click and type on a screen, write and run its own code, or call MCP and API tools, and it is the same model called the same way on desktops, the web, Android, code sandboxes and business APIs.
On the long-workflow desktop benchmark OSWorld 2.0, the company reports Holo4 27B at 61.7% against 81.8% for Opus 5.5, and Holo4 35B-A3B at 30.9%; it says Holo4 still trails the strongest closed models but with orders of magnitude fewer parameters and much lower cost per task. Benchmark costs are estimated from each run’s input and output tokens, and releases, harnesses and task subsets differ between models. The company open-sources every trajectory behind its public benchmark scores, which can be replayed step by step or downloaded from Hugging Face.
Training used its Agentic Task Factory, an internal pipeline that builds interactive environments and verifiable tasks from documentation and screenshots alone and has produced about 10,000 tasks across web apps, MCP servers and desktop environments. Both sizes are available now on the H Models API, with weights on Hugging Face in BF16, FP8, NVFP4 and 4-bit GGUF; the company says drafter checkpoints to speed up inference will follow in the coming days.
Sources
- Holo4: powering generalist computer-use agents — Hugging Face