SeaPilot: Mobile Agent with Self-refining Environment Alignment

By combining cloud-side reasoning with edge-side observation and execution, cloud-edge collaboration has emerged as a promising paradigm for mobile UI agents. However, existing approaches face a fundamental trade-off between cost and accuracy. On one hand, step-by-step cloud interaction ensures high accuracy by uploading UI screens at every step and leveraging the cloud's powerful reasoning capabilities, but this inevitably incurs significant privacy costs for edge data and high computational expenses on the cloud. On the other hand, one-shot cloud planning drastically reduces the demand for edge privacy data and cloud compute by generating a complete plan based solely on the initial UI screen. Yet, this often leads to a substantial drop in accuracy, as the cloud agent may rely on invalid environment assumptions such as unseen app capabilities or UI flows. In this paper, we identify that the root cause of this trade-off lies in the environment assumption gap: the cloud agent lacks prior knowledge of the environment information required for edge-side task execution, and is thus forced to choose between planning with real-time information and planning based on speculative assumptions. To tackle this dilemma, we propose SeaPilot, which proactively provides the cloud agent with the necessary environmental context at the initial task submission stage, thereby achieving the dual benefits of both step-by-step and one-shot methods. To realize this, SeaPilot employs an iterative self-refining mechanism that progressively acquires feedback knowledge from execution failures across diverse tasks, enabling it to learn how to supply precise environmental information for each task in advance. Empirically, SeaPilot improves accuracy by 46.7% over one-shot methods, reduces cloud-token usage by 23.6x compared with step-by-step methods, and reduces privacy cost by 89.6%, achieving a better cost--accuracy trade-off. The code is available at https://anonymous.4open.science/r/SeaPilot-C13C.