import type { Base64EncodedWireTransaction } from '@solana/kit';
/**
 * Converts various transaction formats to a Base64-encoded wire transaction.
 *
 * This utility function handles the conversion of different transaction input types
 * (Buffer, string, or already encoded Base64EncodedWireTransaction) into a consistent
 * Base64EncodedWireTransaction format that can be used with Solana RPC methods.
 *
 * @param tx - The transaction to convert. Can be:
 *   - Buffer: Raw transaction bytes that will be converted to base64
 *   - string: Already base64-encoded transaction string
 *   - Base64EncodedWireTransaction: Already properly typed, returned as-is
 * @returns Base64-encoded wire transaction ready for RPC submission
 *
 * @example
 * ```typescript
 * // Convert Buffer to base64
 * const txBuffer = Buffer.from([1, 2, 3]);
 * const base64Tx = toBase64EncodedWireTransaction(txBuffer);
 *
 * // Pass through already encoded string
 * const encodedTx = "SGVsbG8gV29ybGQ=";
 * const result = toBase64EncodedWireTransaction(encodedTx);
 * ```
 */
export declare function toBase64EncodedWireTransaction(tx: string | Buffer | Base64EncodedWireTransaction): Base64EncodedWireTransaction;