/**
 * Serialization utilities for workflow inputs/outputs.
 * Uses JSON encoding with raw Buffer transport (no base64 round-trip).
 */
export declare function serialize(value: unknown): Buffer;
export declare function deserialize<T>(buf: Buffer | Uint8Array | undefined | null): T;
/** Decode canonical RFC 4648 base64 without Node's permissive truncation/coercion. */
export declare function deserializeBase64(value: unknown, operation: string, field: string): Buffer;
/**
 * Step-output-aware serialize (P5.2): if a `PayloadCodec` is registered for
 * `stepName` (see `codecs.register` in `./payload-codec.js`), wraps `value`
 * in a `{ $mfv: version, value }` envelope before encoding. Steps with no
 * registered codec serialize exactly as `serialize()` always has —
 * byte-identical to pre-P5.2 output.
 *
 * Used only at step-output write time (activity results, side-effect
 * results, signal payloads consumed by waitForSignal) — NOT for workflow
 * input/output or query state, which have no versioning story yet and stay
 * on the plain `serialize()`/`deserialize()` pair.
 */
export declare function serializeStepOutput(stepName: string, value: unknown): Buffer;
/**
 * Step-output-aware deserialize (P5.2): decodes `buf`, then runs it through
 * the registered codec chain for `stepName` (if any) via `codecs.hydrate`.
 * An un-enveloped legacy checkpoint is implicitly version 0. A stored
 * version newer than the registered codec throws `PayloadVersionSkewError`
 * (see `./payload-codec.js`) rather than silently returning mismatched data.
 */
export declare function deserializeStepOutput<T>(stepName: string, buf: Buffer | Uint8Array | undefined | null): T;
export declare function serializeError(error: unknown): {
    error_type: string;
    error_message: string;
};
export declare function deserializeError(errorType: string, errorMessage: string): Error;
export declare function parseDuration(duration: string): number;