import type { OutputEvent, SubagentProgressMeta } from '../types.js';
export type Phase = 'idle' | 'investigating' | 'editing' | 'testing' | 'building' | 'waiting_on_subagent' | 'risky_pending' | 'blocked_by_hook' | 'interrupted' | 'ready_for_review';
export declare function reducePhase(prev: Phase, event: OutputEvent, meta: SubagentProgressMeta | undefined, now: number, lastEventAt: number): Phase;