import { OpenAPIV3 } from 'openapi-types';
/** Error thrown when an external `$ref` is encountered but not allowed. */
export declare class ExternalRefError extends Error {
    readonly ref: string;
    constructor(ref: string);
}
/** Returns true if a `$ref` string points at an http(s) URL. */
export declare function isExternalHttpRef(ref: unknown): ref is string;
export declare function assertNoExternalRefs(node: unknown, seen?: WeakSet<object>): void;
/**
 * Parse and dereference an OpenAPI spec with optional SSRF protection.
 *
 * The SSRF protection targets external `$ref`s embedded *inside* the spec, not
 * the user-supplied input itself: a URL/path passed as the input is trusted
 * (the user typed it) and must still load. When `allowExternalRefs` is false
 * (the default) we:
 *   1. Parse the entry document (http allowed so a URL input is fetched).
 *   2. Scan the parsed tree and reject any external http(s) `$ref`.
 *   3. Dereference with the http resolver disabled — safe because step 2
 *      guaranteed no external refs remain to follow.
 *
 * Step 3 dereferences from the ORIGINAL local-path/object input (not the parsed
 * object) so relative file `$ref`s (e.g. `./schemas.json#/MyType`) resolve
 * against the spec's directory rather than the process cwd. For URL inputs,
 * which can't be re-fetched once http is disabled, it dereferences the parsed
 * object instead (URL specs are single-file or use absolute refs already
 * rejected in step 2).
 *
 * @param input Path, URL, or pre-parsed document
 * @param allowExternalRefs Permit external http(s) `$ref` resolution
 * @returns Fully dereferenced OpenAPI v3 document
 */
export declare function parseSpecSecurely(input: string | OpenAPIV3.Document, allowExternalRefs: boolean): Promise<OpenAPIV3.Document>;