export type TurnState = "understanding" | "exploring" | "acting" | "verifying" | "succeeded" | "partial" | "blocked" | "failed" | "aborted" | "paused_budget";
export interface TurnStateSnapshot {
    readonly schemaVersion: 1;
    readonly state: TurnState;
    readonly revision: number;
    readonly reason?: string | undefined;
}
export declare function createTurnState(initial?: TurnState): TurnStateSnapshot;
export declare function canTransitionTurn(from: TurnState, to: TurnState): boolean;
export declare function transitionTurn(snapshot: TurnStateSnapshot, to: TurnState, reason?: string): TurnStateSnapshot;
export declare function isTerminalTurnState(state: TurnState): boolean;