import type { AugmentConfig } from "../config.js";
/**
 * Thrown when a healthy daemon already owns this state dir. The daemon process
 * itself (not just the connect-or-start client) must refuse to start a second
 * time: two daemons co-opening the same sqlite index race on writes and produce
 * intermittent SQLITE_BUSY. Callers that spawn the daemon treat this as a clean
 * "already up" exit, not a failure.
 */
export declare class DaemonAlreadyRunningError extends Error {
    readonly endpoint: string;
    readonly pid: number;
    constructor(endpoint: string, pid: number);
}
/** Handle to the single-instance slot; release() frees it for the next start. */
export interface InstanceLock {
    release(): Promise<void>;
}
/**
 * Claim the sole-daemon slot for `config.stateDir`, or throw
 * {@link DaemonAlreadyRunningError} if another daemon already holds it.
 *
 * Two independent signals guard the slot:
 *  - the recorded daemon's /health endpoint (authoritative — a daemon that
 *    answers /health owning this stateDir is unambiguously already serving), and
 *  - an exclusive `daemon.pid` lockfile that closes the cold-start window before
 *    the winner becomes healthy. A pidfile is reclaimed when its holder is
 *    provably dead, or when it has aged past the grace window (a crash-stranded
 *    orphan, possibly with a since-reused pid); a live, recent holder is honored.
 *    Reclamation is atomic — an orphan is renamed aside, so of two racing starts
 *    at most one reclaims and the loser honors whoever recreates the slot.
 */
export declare function acquireSingleInstance(config: AugmentConfig): Promise<InstanceLock>;