[Home](./index.md) > [@firebase/functions](./functions.md) > [HttpsCallable](./functions.httpscallable.md) ## HttpsCallable type An HttpsCallable is a reference to a "callable" http trigger in Google Cloud Functions. Signature: ```typescript export declare type HttpsCallable = (data?: RequestData | null) => Promise>; ``` References: [HttpsCallableResult](./functions.httpscallableresult.md)