/**
 * Optional eth decryption key — only needed when testing ENCRYPTED callback
 * payloads in the consumer role. The org's results are ECIES-encrypted to its
 * eth public key; this is the matching eth PRIVATE key (`0x`-hex). Resolution:
 *
 *   1. The `RECLAIM_DECRYPT_KEY` env var (a `0x`-prefixed 32-byte hex key), or
 *   2. A file named `reclaim-decrypt.key` in the project root holding that hex.
 *   3. Absent — plaintext-only testing (no decryption key; encrypted
 *      deliveries surface a clear error).
 *
 * The hex is loaded via the client's `loadDecryptionKey` and passed straight
 * through as `ReclaimConfig.credential` / to `decryptCallback`.
 */
import { type DecryptionKey } from '@reclaimprotocol/client';
/**
 * Load the optional decryption key. Returns `undefined` when no key is
 * configured (the consumer then handles only plaintext deliveries).
 */
export declare function resolveDecryptionKey(projectDir?: string): Promise<DecryptionKey | undefined>;