export interface RoleDepsProbe {
    env: NodeJS.ProcessEnv;
    /** The pinned SDK loads without an install. */
    sdkPresent: () => boolean;
    /** Installs and verifies the pinned SDK. */
    install: () => Promise<unknown>;
}
export type RoleDepsResult = {
    status: 'present' | 'installed' | 'not-needed' | 'in-role' | 'disabled';
} | {
    status: 'failed';
    error: string;
};
export declare const defaultRoleDepsProbe: (env?: NodeJS.ProcessEnv) => RoleDepsProbe;
/** How long a failed install is reported without retrying: every session
 *  start would otherwise spawn npm again (offline, each waits out the fetch
 *  timeout), and a role can cause session starts. */
export declare const ROLE_DEPS_RETRY_MS: number;
/** The longest a session start waits for an install; the install goes on in
 *  the background and the next session start finds it. */
export declare const ROLE_DEPS_WAIT_MS: number;
/** Per-process install state. Tests pass a fresh one. */
export interface RoleDepsState {
    done?: RoleDepsResult;
    inFlight?: Promise<RoleDepsResult>;
    failed?: {
        at: number;
        result: RoleDepsResult;
    };
    now: () => number;
}
export declare const newRoleDepsState: (now?: () => number) => RoleDepsState;
/** Makes sure the SDK a role running `runtime` may need is installed. Never
 *  throws: a failure is returned, and the role then fails with the
 *  operator's command. Synchronous when there is nothing to install, or once
 *  it is installed, so a session start does not yield for it. One install at
 *  a time per process; after a failure the same failure is returned for
 *  ROLE_DEPS_RETRY_MS. `probe` and `state` are for tests. */
export declare function ensureRoleDeps(runtime: string, probe?: RoleDepsProbe, state?: RoleDepsState): RoleDepsResult | Promise<RoleDepsResult>;
/** Waits for `pending` until the session is aborted or `ms` pass; the
 *  install itself is not cancelled. */
export declare function waitRoleDeps(pending: Promise<RoleDepsResult>, signal: AbortSignal, ms?: number): Promise<RoleDepsResult>;
/** The audit line for an install the host just did. */
export declare const roleDepsInstalled: () => string;
/** The audit line for a failed install. */
export declare const roleDepsFailure: (error: string) => string;
/** The audit event for a session start's install result, if it needs one. */
export declare function roleDepsAudit(r: RoleDepsResult): {
    reason: string;
    msg: string;
} | undefined;
//# sourceMappingURL=role-deps.d.ts.map