CoAdapt-GUI: Joint Workflow Context and Policy Adaptation for Unseen GUI Applications

To address the brittleness of mobile GUI agents on unseen applications, we study test-time adaptation using limited target interaction without target demonstrations. We introduce CoAdapt-GUI, a test-time adaptation (TTA) framework that jointly adapts structured workflow context and policy from the agent’s own target-app rollouts and rewards. This context guides target adaptation with transferable pro- cedures, failure modes, and verification rules while excluding app-bound source state. For policy adaptation, task–context-matched group-relative optimization updates a LoRA adapter on a frozen vision–language model. Across two unseen- app evaluations, CoAdapt-GUI reaches 45.0% on AndroidWorld-Generalization, compared with 37.08% for the reproduced Policy-Only TTA baseline, and raises AndroidWorld Plus performance from 37.9% to 52.6%. These results show that transfer-constrained workflow context provides substantial gains and that joint policy adaptation further improves held-out performance.