/**
 * Typed errors for every way a Substack call can fail.
 *
 * Substack has no public API. We call the same authenticated JSON endpoints the
 * web app calls, so failures arrive in three different shapes: a JSON body, a
 * plain-text body, or a multi-kilobyte Cloudflare HTML block page. A single
 * "Substack API error" string for all of them tells the calling model nothing
 * it can act on, so each status maps to a class with a message that names the
 * actual fix.
 */
export declare class SubstackError extends Error {
    readonly status: number;
    readonly endpoint: string;
    readonly detail: string;
    constructor(message: string, status: number, endpoint: string, detail?: string);
    /** What the model should show the user. Includes the actionable hint. */
    toJSON(): Record<string, unknown>;
}
/** 401/403, or a Cloudflare 1010 block on a custom domain. */
export declare class AuthenticationError extends SubstackError {
}
/** 429. Substack does not send Retry-After, so the client backs off on its own. */
export declare class RateLimitError extends SubstackError {
}
/** 400 — bad arguments reached the endpoint. */
export declare class ValidationError extends SubstackError {
}
/** 404 — the draft, post, note or publication does not exist. */
export declare class NotFoundError extends SubstackError {
}
/** 5xx — Substack's problem, worth retrying. */
export declare class ServerError extends SubstackError {
}
/** Synthetic 408. No response arrived before our own deadline. */
export declare class TimeoutError extends SubstackError {
}
/** The server is running with writes disabled, or a confirm was missing. */
export declare class WriteBlockedError extends SubstackError {
    constructor(message: string);
}
/**
 * Pull something readable out of a response body.
 *
 * Tries JSON first (`{error}` / `{errors:[]}` / `{message}`), falls back to raw
 * text. Caps at 500 characters so a Cloudflare HTML block page does not become
 * the entire error message.
 */
export declare function extractErrorDetail(body: string): string;
/** True when a Cloudflare block page is pretending to be an auth failure. */
export declare function isCloudflareBlock(body: string): boolean;
/** Map an HTTP status onto the right error class. */
export declare function errorForStatus(status: number, endpoint: string, body: string): SubstackError;