notessamuele onelia

Background Execution Within iOS Time Limits

The Idea

iOS gives a backgrounded app roughly 30 seconds before it’s suspended or killed. For an agent in the middle of a loop, that 30 seconds is your only window to land things safely. Use it for three jobs in order:

  1. Complete the current tool call if it can finish in time.
  2. Checkpoint the session state so it can be resumed.
  3. Transition gracefully to a backgrounded status.

A working shape:

func prepareForBackground() {
    backgroundTaskId = UIApplication.shared
        .beginBackgroundTask(withName: "AgentProcessing") {
            handleBackgroundTimeExpired()
        }
}
 
func handleBackgroundTimeExpired() {
    for session in sessions where session.status == .running {
        session.status = .backgrounded
        Task { await saveSession(session) }
    }
}
 
func handleForeground() {
    for session in sessions where session.status == .backgrounded {
        Task { await resumeSession(session) }
    }
}

For Truly Long-Running Agents

If a task genuinely needs hours, mobile alone isn’t enough. The pattern is a server-side orchestrator that can run for as long as it needs, with the mobile app acting as a viewer and input mechanism. The phone becomes the cockpit; the engine runs elsewhere.

The article flags this as Claude’s contribution from building — it works in practice, but it’s “one way to do it” rather than a battle-tested standard.

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