/**
 * Shared utility functions for paper-search-agent MCP server.
 */
/**
 * Normalize a DOI string: lowercase, trim whitespace, remove URL prefix.
 */
export declare function normalizeDoi(raw: string): string;
/**
 * Infer a publisher hint from a DOI prefix.
 * Returns null if the prefix is not recognized.
 */
export declare function publisherFromDoiPrefix(doi: string): string | null;
/**
 * Generate a filesystem-safe string from a DOI.
 */
export declare function doiToSafePath(doi: string): string;
//# sourceMappingURL=doi.d.ts.map