/**
 * Thin fetch-based HTTP client for the Wristband API.
 *
 * Wraps native `fetch` (Node 20+) with a base URL, default headers, and
 * structured error handling. Non-2xx responses are thrown as {@link FetchError}
 * instances carrying both the raw `Response` and the parsed body.
 */
export declare class WristbandApiClient {
    private readonly baseURL;
    private readonly defaultHeaders;
    constructor(wristbandApplicationVanityDomain: string);
    private request;
    /**
     * Performs a GET request to the given API endpoint.
     *
     * @param endpoint - Path relative to the base URL.
     * @param headers - Optional additional or override headers.
     * @returns The parsed JSON response body.
     * @throws {FetchError} On non-2xx responses.
     */
    get<T>(endpoint: string, headers?: HeadersInit): Promise<T>;
    /**
     * Performs a POST request to the given API endpoint.
     *
     * @param endpoint - Path relative to the base URL.
     * @param body - Request body (typically a form-encoded string).
     * @param headers - Optional additional or override headers.
     * @returns The parsed JSON response body.
     * @throws {FetchError} On non-2xx responses.
     */
    post<T>(endpoint: string, body: any, headers?: HeadersInit): Promise<T>;
}