import * as t from 'io-ts';
export declare const quantity: t.Type<import("ts-essentials").Opaque<"Quantity", string>, string, unknown>;
export declare const hexData: t.Type<import("ts-essentials").Opaque<"HexData", string>, string, unknown>;
export declare const hash: t.Type<import("ts-essentials").Opaque<"Hash", string>, string, unknown>;
export declare const address: t.Type<import("ts-essentials").Opaque<"Address", string>, string, unknown>;
export declare const undefinable: <A, O>(type: t.Type<A, O, unknown>) => t.Type<A | undefined, O | null, unknown>;