import nacl from 'tweetnacl';
export default class RequestBehaviour {
    env?: string;
    lang?: string;
    from?: string;
    sdk_version?: string;
    protected sdk_key_pair?: nacl.BoxKeyPair;
    constructor();
    getSDKKeyPair(): nacl.BoxKeyPair | undefined;
    isEncryptable(): boolean;
    withEncryption(publicKey?: string | null): string | null;
    toJson(): string;
}