/**
 * Rate limit reason classification and backoff calculation utilities.
 * Ported from opencode-antigravity-auth plugin for consistency.
 */
export type RateLimitReason = "QUOTA_EXHAUSTED" | "RATE_LIMIT_EXCEEDED" | "MODEL_CAPACITY_EXHAUSTED" | "SERVER_ERROR" | "UNKNOWN";
/**
 * Classify a rate-limit error message into a reason category.
 * Priority order: MODEL_CAPACITY > RATE_LIMIT > QUOTA > SERVER_ERROR > UNKNOWN.
 *
 * "resource exhausted" maps to MODEL_CAPACITY (transient, short wait)
 * "quota exceeded" maps to QUOTA_EXHAUSTED (long wait, switch account)
 */
export declare function parseRateLimitReason(errorMessage: string): RateLimitReason;
/**
 * Calculate backoff delay in ms for a given rate limit reason.
 * MODEL_CAPACITY gets jitter to prevent thundering herd.
 */
export declare function calculateRateLimitBackoffMs(reason: RateLimitReason): number;
export declare function isUsageLimitError(errorMessage: string): boolean;