import type { AuthLocale } from '../../i18n/keys.js';
/**
 * Resolve a server error to a localized message. Pass the `code` and `error`
 * fields from a handler's JSON error body plus the active `AuthLocale`:
 *
 * ```ts
 * error = errorMessageFromCode(data.code, t, data.error);
 * ```
 *
 * Resolution order:
 * 1. a known `code` with a localized string → the translation;
 * 2. otherwise the raw server `error` prose (back-compat with non-i18n
 *    consumers and any code not yet translated);
 * 3. otherwise `undefined`, so the caller can apply its own generic fallback.
 *
 * `validation_error` deliberately resolves to the server prose when one is
 * supplied (the field-level "email is invalid" message is more useful than a
 * generic localized string); only a code-less/prose-less validation error uses
 * the generic localized text.
 */
export declare function errorMessageFromCode(code: string | undefined, t: AuthLocale, fallbackError?: string): string | undefined;