OS-Native Agents: Managing User Tasks in the Dynamic Mobile World

Mobile agents can perform an increasingly broad range of tasks on behalf of users. Yet the mobile world continues to change after an agent has acted: application and system states evolve, new information arrives, and users revise their plans. In conventional mobile interaction, the operating system (OS) delivers relevant changes and governs access to device resources, while users decide which ongoing tasks require attention and how to respond across applications. Delegating this coordination to an agent requires OS support across interactions, including access to relevant state changes, cross-application capabilities, and execution under user authorization. We therefore introduce OS-native agents, which are recognized by the operating system and integrated into its native state, capability, and trust mechanisms. The OS provides system-level interfaces through which the agent observes runtime application and system state, discovers and composes structured capabilities exposed by applications and system services, and executes actions across apps and services through an OS contract for identity, authorization, and audit. We realize OS-native agents on Android and introduce DynamicWorld, a replayable benchmark for managing multiple ongoing tasks in a shared Android environment, with controlled changes in applications, system state, and user requests.