/*`,
 * not `application/json`). This predicate fixes that asymmetry by making
 * JSON the default unless the client explicitly opts into HTML.
 */
export declare function isApiRequest(req: Request | { headers: Headers }): boolean;
/**
 * "Is this request JSON-shaped?" — the single source of truth used across
 * the framework to decide JSON vs HTML for responses (errors, primitives,
 * empty results) and to widen request-body parsing to every JSON variant.
 *
 * The historical bug was scattered ad-hoc checks: `error-handler` looked at
 * `Accept`, `formatResult` ignored the request entirely, `parseRequestBody`
 * did `contentType.includes('application/json')` so `application/vnd.api+json`
 * went unparsed. Centralizing the decision here means a future tweak (e.g.,
 * treating an `apiResponse: true` route group as always-JSON) lands in one
 * place and every response path picks it up.
 */
/**
 * Matches `application/json` plus any RFC-6838 structured-suffix subtype:
 * `application/vnd.api+json`, `application/ld+json`, `application/hal+json`,
 * `application/problem+json`, etc. Case-insensitive; tolerates a trailing
 * `;` (for `;charset=utf-8`) or end-of-string.
 */
export declare const JSON_CONTENT_TYPE: unknown;