import type { Api, FetchImpl, Model } from "../types.js";
/**
 * The one fetch every inference request goes through. Per call it applies, in
 * order: the inference User-Agent default, `NODE_EXTRA_CA_CERTS`, the
 * per-provider proxy, and `PI_REQ_DEBUG` request/response recording — then
 * calls `fetchImpl` (or the model's default fetch) exactly once. Providers
 * never layer transport concerns themselves.
 *
 * Idempotent: the built fetch is stamped and returned as-is on later passes.
 * `streamSimple` re-enters `stream`, and `streamSimpleRequest` re-enters itself
 * on auth retries, so without the stamp each entry point would add another
 * layer (three PI_REQ_DEBUG dumps for one request).
 */
export declare function transportFetch(model: Model<Api>, fetchImpl: FetchImpl | undefined): FetchImpl;
/** Options-bag form of {@link transportFetch}; returns `options` untouched when its fetch is already built. */
export declare function withTransportFetch<T extends {
    fetch?: FetchImpl;
}>(model: Model<Api>, options: T): T;