# JAM: A Unified Action Model Framework Decoupling Backbone, Objective, and Inference Mechanism

- Source: HuggingFace Daily Papers
- Published: 2026-10-27T00:00:00.000Z
- RoboHot: https://robohot.news/en/items/nqtkzs6dg6pczsvbrj8aeusby
- Original: https://huggingface.co/papers/2610.37219

## Summary

The study proposes the Just Action Model (JAM) framework, which breaks down the differences between VLA and WAM into three separable choices: backbone initialization, the future-observation objective, and whether that loss mechanism is retained at inference. It uses a pretrained visual backbone plus an action expert, trained with an action loss and a foresight loss.