/** The handoff that is running, as the handoff script wrote it down. */
export interface Lease {
    /** The issue whose window is open. */
    issue: string;
    /** The handoff script's own pid, which lives as long as the tool does. */
    pid: number;
    startedAt: string;
}
export declare function leasePath(projectDir: string): string;
/**
 * The lease being held right now, or null.
 *
 * A file naming a process that has gone is cleared as it is read: the handoff
 * that wrote it cannot come back to tidy up, and leaving it would mean every
 * later read pays the same syscall to reach the same answer.
 */
export declare function readLease(projectDir: string): Lease | null;
/** Whether anything holds the queue. What the pump asks. */
export declare function leaseHeld(projectDir: string): boolean;
export declare function clearLease(projectDir: string): void;
/**
 * The shell that takes the lease, runs the tool, and drops it however it ends.
 *
 * Written as lines for the handoff script to splice in. Three things it must
 * keep, each of which is a queue that stops moving if it slips:
 *
 * 1. **No `exec`.** Replacing the shell with the tool leaves nothing to run the
 *    trap, so the lease outlives the session and its pid stays alive because it
 *    IS the tool's pid.
 * 2. **The trap covers the ways a Terminal really ends**, which is mostly
 *    somebody closing the window: HUP, not just a clean EXIT.
 * 3. **`$$` is the script's own pid**, and the script stays in the foreground
 *    for the whole session, so "the lease's process is alive" and "the agent is
 *    still going" are the same question.
 */
export declare function leaseScript(projectDir: string, issue: string, command: string): string;