/**
 * Run `fn` with `signal` as the ambient call signal, for `fn` and everything it awaits.
 *
 * @param signal The deadline's signal.
 * @param fn Starts the provider call. The context has to be live at the moment the client's
 *   `fetch` is invoked, which is why this wraps the *start* of the call rather than the `await` of
 *   its result.
 * @returns Whatever `fn` returns, unchanged.
 */
export declare function runWithCallSignal<T>(signal: AbortSignal, fn: () => T): T;
/**
 * The ambient call signal, or `undefined` outside any deadline.
 */
export declare function currentCallSignal(): AbortSignal | undefined;
/**
 * Wrap a `fetch` so that every request it makes is **also** aborted by the ambient call signal.
 *
 * The request's own signal is preserved rather than replaced. The `ollama` client aborts its
 * streamed requests through a controller of its own, and dropping that would trade one leak for
 * another — so the two are composed, and the request aborts when *either* fires.
 *
 * Outside a deadline there is no ambient signal and the call is passed through untouched, so
 * installing this on a client costs nothing when no deadline is running.
 *
 * @param base The fetch to delegate to. Defaults to the global one.
 * @returns A fetch with the same signature, safe to hand to a client constructor.
 */
export declare function ambientSignalFetch(base?: typeof fetch): typeof fetch;