import { z } from "zod";
import type { Host } from "../../host/host.js";
export declare const AttachRecordSchema: z.ZodObject<{
    pid: z.ZodNumber;
    program: z.ZodString;
    node: z.ZodString;
    startedAt: z.ZodNumber;
}, z.core.$strict>;
export type AttachRecord = z.infer<typeof AttachRecordSchema>;
export declare function sessionsDir(host: Pick<Host, "settings" | "system">): string;
export declare function recordPaths(dir: string, pid: number): {
    json: string;
    sock: string;
};
/** Why the sessions directory cannot be used. */
export type DirectoryRefusal = {
    refused: string;
};
/** The sessions directory, made with mode `0700` when missing, and
 *  refused unless the current user owns it and no group or world bits are
 *  set. The safety argument for attach rests on this check: the socket in
 *  it is also `chmod 0600`, but that happens after `listen`, with a short
 *  window at the umask's mode. The run and the CLI both call this. */
export declare function ensureSessionsDir(dir: string): DirectoryRefusal | null;
/** Write `<pid>.json`. The path is removed first and the file created
 *  anew (`wx`), so a symlink left at that name is replaced, not followed. */
export declare function writeRecord(dir: string, record: AttachRecord): void;
/** Remove one run's record and socket. Paths are built here from the
 *  directory and a pid, never taken from outside, so this can only ever
 *  delete files a run wrote. */
export declare function removeRecord(dir: string, pid: number): void;
/** The record in `<pid>.json`, or null when there is none, it is not a
 *  record, or its pid is not the file's: a record is only trusted to say
 *  what its name says, so a hand-edited file cannot point the CLI at
 *  another process. */
export declare function readRecord(dir: string, pid: number): AttachRecord | null;
export declare function listRecords(dir: string): AttachRecord[];
/** Delete the records whose process is gone, and nothing else. */
export declare function removeStale(dir: string, records: readonly AttachRecord[]): AttachRecord[];