import { z } from "@hono/zod-openapi";
declare const optionsSchema: z.ZodObject<{
    upstream_url: z.ZodString;
    preserve_host: z.ZodDefault<z.ZodBoolean>;
    timeout_ms: z.ZodOptional<z.ZodNumber>;
}, z.core.$strip>;
type Options = z.infer<typeof optionsSchema>;
/**
 * The response for a request whose body could not be read up front: 408 when
 * the client was too slow, 400 when the stream failed.
 */
export declare function bodyReadFailure(err: unknown): Response;
export declare function buildUpstreamRequest(options: Options, req: Request, bodyTimeoutMs: number): Promise<{
    target: URL;
    init: RequestInit;
}>;
export declare const httpHandler: import("../registry").HandlerDefinition<{
    upstream_url: string;
    preserve_host: boolean;
    timeout_ms?: number | undefined;
}>;
export {};