/** The installable package name behind a module specifier, or null if not a bare package. */
export declare function packageRoot(specifier: string): string | null;
/** All bare package roots imported/required/re-exported in a file's source. */
export declare function extractImportedPackages(code: string): Set<string>;
/** Walk a source tree and collect every imported package root (node_modules excluded). */
export declare function collectImportedPackages(root: string, opts?: {
    maxFiles?: number;
}): Set<string>;
export type ReachabilityStatus = "imported" | "not_imported";
export interface ReachabilityResult {
    reachable: boolean;
    status: ReachabilityStatus;
}
/**
 * Annotate each package name with whether it is imported anywhere under `root`.
 * Pass `importedOverride` (a precomputed set) to avoid a filesystem walk (used in tests
 * and to share one walk across many packages).
 */
export declare function analyzeReachability(packageNames: string[], root: string, importedOverride?: Set<string>): Map<string, ReachabilityResult>;