export declare const DEFAULT_STALL_TIMEOUT_MS: number;
export declare const STALL_RECOVERY_PROMPT: string;
export type StallStatus = 'interrupt_requested' | 'recovery_started' | 'progress_resumed' | 'recovery_completed' | 'blocked_cancel' | 'blocked_recovery' | 'blocked_restall' | 'blocked_persistence' | 'blocked_previous_attempt' | 'blocked_evidence' | 'superseded';
export interface StallDiagnostic {
    version: 1;
    kind: 'stall_recovery';
    eventId: string;
    session: string;
    turn: string;
    status: StallStatus;
    evidence: 'adapter_transport' | 'no_progress';
    idleMs: number;
}
export interface StallObservation {
    sessionId: string;
    generation: string;
    turnId: string;
    startedAt: number;
    lastProgressAt: number;
    progressCount: number;
    transportFailures: number;
    safe: boolean;
    boundaryEvidenceAvailable?: boolean;
}
/** Presence, including an incomplete claim, restores conservative mail policy. */
export declare function hasStallRecoveryClaim(stateDir: string, sessionId: string): boolean;
/** ACP has no turn IDs on tool updates. Reuse across turns is ambiguous. */
export declare class StallToolHistory {
    private readonly turns;
    private healthy;
    private readonly directory;
    private readonly path;
    private readonly session;
    constructor(stateDir: string, sessionId: string, resume: boolean);
    available(): boolean;
    /** Record before relying on a tool event. False means cancellation is unsafe. */
    observe(toolId: string, turnId: string): boolean;
    private persist;
}
/**
 * One durable attempt per ACP session, deliberately stricter than one per turn.
 * A restarted supervisor never guesses whether cancellation or recovery ran.
 * Claim files are never reclaimed automatically, including malformed/empty ones.
 */
export declare class StallWatchdog {
    private readonly options;
    private checking;
    private disabled;
    private unavailableTurn?;
    constructor(options: {
        stateDir: string;
        timeoutMs: number;
        previouslyClaimed?: boolean;
        now(): number;
        observe(): StallObservation | undefined;
        recover(observed: StallObservation, report: (status: StallStatus) => void): Promise<void>;
        diagnostic(event: StallDiagnostic): void;
    });
    tick(): Promise<void>;
}