import { type NodeRow } from '../canvas/index.js';
import type { PiInvocation } from './launch.js';
/** View-side launch hints the broker host needs beyond the PiInvocation. The
 *  broker uses `cwd` + `resuming`; `name` is carried for the node's display. */
export interface LaunchPlacement {
    cwd: string;
    name: string;
    resuming: boolean;
}
/** A handle to a node's running engine container. The broker host supervises via
 *  the broker pid recorded as pi_pid; no tmux placement coords exist (the engine
 *  is never in a pane). */
export interface HostHandle {
    /** Supervised pid (signal-0 target). Null means the host failed to spawn an
     *  engine at all. Spawn/revive record this pid immediately; the broker
     *  re-records the same pid during extension bind. */
    pid: number | null;
    /** Real child-exit signal from the launch handle. Resolves when the detached
     *  broker exits, so readiness waits can fail fast without pid probes. */
    exited: Promise<{
        code: number | null;
        signal: NodeJS.Signals | null;
    }>;
}
export interface Host {
    /** Bring a node's ENGINE into existence from its launch recipe; return a
     *  supervisable handle. */
    launch(nodeId: string, inv: PiInvocation, opts: LaunchPlacement): HostHandle;
    /** Is this node's engine alive? PURE / non-mutating. `string | NodeRow` so
     *  both call sites — the revive guard (passes the id) and the daemon (passes a
     *  row) — share one selector. For the broker this IS isPidAlive(pi_pid). */
    isAlive(node: string | NodeRow): boolean;
    /** Tear the engine down (close/cancel teardown). */
    teardown(nodeId: string): void;
    /** Deliver an OS signal to the engine container — present so the daemon never
     *  reaches around the abstraction. */
    signal(nodeId: string, sig: NodeJS.Signals): void;
}
/** Validate the broker launch recipe before we detach a child process. This is
 *  the fast-fail seam for known module/path errors: a bad engine resolve or a
 *  missing plain session path throws here, before spawn(). */
export declare function preflightBrokerLaunch(nodeId: string, inv: PiInvocation, cwd: string): void;
export declare const headlessBrokerHost: Host;