import type { SessionActivity } from './types.js';
/**
 * How long after the agent's last session update it still counts as working.
 *
 * FLEET-002: a wake delivered by ACP steering answers `startedNewTurn` and runs
 * an entire turn that fleet never receives a `session/prompt` response for (ACP
 * has no turn-end session update), so `readiness` stays `idle` throughout. Tool
 * reservations and update recency are the only activity evidence fleet holds.
 * The trade-off is deliberate and one-directional: at worst a role reads busy
 * for one window after it genuinely stopped, instead of reading ready — or
 * being classified stalled — while it is executing tools.
 */
export declare const ACTIVITY_WINDOW_MS = 60000;
export type ActivityState = 'active' | 'quiet' | 'unobservable';
export interface ObservedActivity {
    state: ActivityState;
    activeToolCalls?: number;
    lastUpdateAt?: string;
}
/**
 * Classify agent-side activity. `unobservable` is NOT `quiet`: absent evidence
 * must never be reported as "doing nothing".
 */
export declare function classifyActivity(activity: SessionActivity | undefined, now?: number): ObservedActivity;
/**
 * One operator-facing line that never lets turn occupancy pose as liveness:
 * the readiness value is labelled as the turn field it is, and the activity
 * verdict is stated separately with the evidence behind it.
 */
export declare function describeSessionState(readiness: string | undefined, activity: SessionActivity | undefined, now?: number): string;