/**
 * NXL codec — compact wire format for MCP responses.
 *
 * Achieves ~70% token reduction vs JSON by:
 *   - Key shortcodes: "status" → "s", "progress" → "p", etc.
 *   - Omitting null/undefined fields
 *   - Compact boolean: true → 1, false → 0
 *   - Short number format (no trailing zeros)
 *   - Flat k:v space-separated for simple objects
 *   - NXLB block format for arrays/nested objects
 *
 * Wire contract: responses prefixed with `NXL1 ` marker.
 * Clients that don't understand NXL request format=json (default).
 */
/** Encode an object/array to NXL wire format string. */
export declare function encodeNxl(data: unknown): string;
/** Decode an NXL wire format string back to a plain object. */
export declare function decodeNxl(nxl: string): unknown;
/** Parse flat k:v space-separated line (top-level NXL1 objects) */
export declare function decodeFlatLine(line: string): Record<string, unknown>;
/** Whether a string is NXL-encoded. */
export declare function isNxl(s: string): boolean;
