/**
 * Agent identity: BIP-39 mnemonic → secp256k1 keypair (Ethereum-style).
 *
 * agent_id = 0x<address> (same as payment_address — single identity).
 * Signing format: EIP-191 personal_sign → ecrecover on server.
 *
 * Storage:
 *   mnemonic.txt  — 12-word phrase (PRIMARY backup, import to Trust Wallet)
 *   agent.key     — secp256k1 private key hex (convenience, derived from mnemonic)
 */
export interface Identity {
    address: string;
    publicKeyHex: string;
    privateKeyHex: string;
}
export declare function generateMnemonic(): string;
export declare function isValidMnemonic(mnemonic: string): boolean;
export declare function mnemonicToIdentity(mnemonic: string): Identity;
export declare function addressFromPrivateKey(privateKeyHex: string): string;
export interface SignedMessage {
    signature: string;
    address: string;
}
export declare function signEip191(privateKeyHex: string, message: string): Promise<SignedMessage>;
export declare function verifyEip191(message: string, signature: string): {
    ok: boolean;
    address?: string;
    error?: string;
};