/**
 * GitHub Copilot intermittently rejects preview models (gpt-5.3-OpenAI code backend,
 * gpt-5.4, gpt-5.4-mini, ...) with HTTP 400 `model_not_supported`, even
 * though the model is listed as enabled on the user's account via `/models`.
 *
 * Root cause: Copilot's request-routing backend is rolled out per OAuth
 * client. Our OAuth client id is shared with opencode; VS Code uses its own
 * client and sees full availability, so the same account may succeed in VS
 * Code and flap between 200/400 here. See opencode#13313 and copilot-cli#2597.
 *
 * Retrying the identical request 2-3 times almost always lands on a backend
 * that has the model, so we wrap the initial request with a short retry loop.
 */
export declare function isCopilotTransientModelError(error: unknown): boolean;
/**
 * Wrap an initial Copilot request so transient `model_not_supported` 400s are
 * retried a small number of times. No-op for non-Copilot providers.
 *
 * The callback **MUST** create a fresh in-flight request each invocation — a
 * once-consumed AsyncIterable cannot be re-iterated.
 */
export declare function callWithCopilotModelRetry<T>(fn: () => Promise<T>, options: {
    provider: string;
    signal?: AbortSignal;
    retryBaseDelayMs?: number;
    fallbackManaged?: boolean;
}): Promise<T>;