/**
 * EIP-1559 (type-2) transaction serialization and signing.
 *
 * Produces the signed raw transaction hex ready for broadcast.
 */
/** Parameters for an EIP-1559 transaction. All numeric values are in wei (bigint). */
export interface Eip1559TxParams {
    /** Chain ID (e.g. 1 for Ethereum mainnet). */
    chainId: bigint;
    /** Sender nonce. */
    nonce: bigint;
    /** Max priority fee per gas (tip) in wei. */
    maxPriorityFeePerGas: bigint;
    /** Max fee per gas (base + tip cap) in wei. */
    maxFeePerGas: bigint;
    /** Gas limit. */
    gasLimit: bigint;
    /** Recipient address (20 bytes hex with 0x prefix). */
    to: string;
    /** Value to send in wei. */
    value: bigint;
    /** Calldata (hex with 0x prefix). Empty for plain ETH transfers. */
    data: string;
}
/**
 * Signs an EIP-1559 transaction and returns the raw signed transaction hex
 * ready for broadcast (with `0x` prefix).
 *
 * @param tx - Transaction parameters.
 * @param privateKey - 32-byte private key.
 * @returns Signed raw transaction as a hex string with `0x` prefix.
 */
export declare function signEip1559Transaction(tx: Eip1559TxParams, privateKey: Uint8Array): string;
/** Parameters for a legacy (pre-EIP-1559) transaction. All numeric values in wei (bigint). */
export interface LegacyTxParams {
    /** Chain ID (e.g. 56 for BSC). */
    chainId: bigint;
    /** Sender nonce. */
    nonce: bigint;
    /** Gas price in wei. */
    gasPrice: bigint;
    /** Gas limit. */
    gasLimit: bigint;
    /** Recipient address (20 bytes hex with 0x prefix). */
    to: string;
    /** Value to send in wei. */
    value: bigint;
    /** Calldata (hex with 0x prefix). Empty for plain transfers. */
    data: string;
}
/**
 * Signs a legacy (type-0) transaction and returns the raw signed transaction hex
 * ready for broadcast (with `0x` prefix).
 *
 * Uses EIP-155 replay protection.
 *
 * @param tx - Transaction parameters.
 * @param privateKey - 32-byte private key.
 * @returns Signed raw transaction as a hex string with `0x` prefix.
 */
export declare function signLegacyTransaction(tx: LegacyTxParams, privateKey: Uint8Array): string;