/**
 * EVM X402 payment signing.
 *
 * Two schemes are supported and produce different envelopes:
 *
 * - `exact` — EIP-3009 `TransferWithAuthorization` against the token's own
 *   EIP-712 domain. Pre-authorises the exact amount in the 402 response.
 * - `upto`  — Permit2 `PermitWitnessTransferFrom` against the Permit2 EIP-712
 *   domain, with the AceData upto-proxy as spender. The signer authorises a
 *   ceiling; the facilitator settles for any amount ≤ that ceiling at /record
 *   time (zero settles with no on-chain transaction).
 *
 * Both work with any EIP-1193 provider (MetaMask, WalletConnect, etc.) — only
 * `eth_signTypedData_v4` is used.
 */
import type { EVMProvider, PaymentRequirement, X402PaymentEnvelope } from './types.js';
/** Canonical CREATE2 deployment of the Uniswap Permit2 contract. */
export declare const PERMIT2_ADDRESS = "0x000000000022D473030F116dDEE9F6B43aC78BA3";
/** Canonical CREATE2 deployment of the AceData upto-proxy spender. */
export declare const X402_UPTO_PERMIT2_PROXY_ADDRESS = "0x4020A4f3b7b90ccA423B9fabCc0CE57C6C240002";
export declare function signEVMPayment(requirements: PaymentRequirement, provider: EVMProvider, address: string): Promise<X402PaymentEnvelope>;
/**
 * Build the Permit2 `PermitWitnessTransferFrom` typed-data object.
 *
 * Mirrors the Python reference (`acedatacloud_x402.signing.evm._build_upto_typed_data`)
 * and the facilitator's `chain_handlers.upto_constants.build_upto_permit2_typed_data`
 * byte-for-byte: any drift breaks signature recovery.
 *
 * Critical:
 *   - The Permit2 EIP-712 domain has **no** `version` field. Adding one
 *     changes the digest and the facilitator recovers a different signer.
 *   - The witness struct is named `Witness` (NOT `X402Witness`).
 *   - The token's own domain is irrelevant — Permit2 holds the allowance.
 */
export declare function buildUptoTypedData(requirements: PaymentRequirement, params: {
    from: string;
    permittedAmount: bigint | string | number;
    nonce: bigint | string | number;
    deadline: bigint | string | number;
    validAfter: bigint | string | number;
}): {
    types: {
        PermitWitnessTransferFrom: {
            name: string;
            type: string;
        }[];
        TokenPermissions: {
            name: string;
            type: string;
        }[];
        Witness: {
            name: string;
            type: string;
        }[];
    };
    primaryType: "PermitWitnessTransferFrom";
    domain: {
        name: string;
        chainId: number;
        verifyingContract: string;
    };
    message: {
        permitted: {
            token: string;
            amount: string;
        };
        spender: string;
        nonce: string;
        deadline: string;
        witness: {
            to: string;
            facilitator: string;
            validAfter: string;
        };
    };
};
/**
 * Sign a Permit2 `PermitWitnessTransferFrom` envelope (`upto` scheme).
 *
 * `requirements.maxAmountRequired` is the **ceiling** the payer signs over.
 * The facilitator may settle any amount `≤` that ceiling at `/record` time.
 *
 * The signer must have already approved Permit2 to pull the token —
 * see {@link approvePermit2} for the one-time on-chain approval.
 */
export declare function signEVMUptoPayment(requirements: PaymentRequirement, provider: EVMProvider, address: string, opts?: {
    validAfter?: number;
    deadlineBuffer?: number;
    nonce?: bigint | string;
}): Promise<X402PaymentEnvelope>;