export type XPaymentAuthorization = {
    from: string;
    to: string;
    value: string;
    validAfter: string;
    validBefore: string;
    nonce: string;
};
export type XPaymentPayload = {
    signature: string;
    authorization: XPaymentAuthorization;
};
export type XPaymentHeader = {
    x402Version: 1;
    scheme: string;
    network: string;
    payload: XPaymentPayload;
};
export type XPaymentResponseHeader = {
    x402Version: 1;
    scheme: string;
    network: string;
    payload: Record<string, any>;
};
export type PaymentLike = XPaymentHeader | XPaymentResponseHeader;
export declare function isXPayment(obj: any): obj is XPaymentHeader;
export declare function isXPaymentResponse(obj: any): obj is XPaymentResponseHeader;
export declare function normalizePaymentLike<T extends PaymentLike>(input: T): T;
export declare function synthesizePaymentHeaderValue(p: PaymentLike): string;
export declare function parsePaymentHeaderValue(s: string): PaymentLike | null;
export declare function deriveExtendedAppFromPayment(p: XPaymentHeader): Record<string, string>;