Invoke Callable functions

On the client, we invoke callable functions through specific handlers provided by the SDK.

configure a functions helper with the firebase project and the region

• Since a client can interact with separate Firebase projects, we specify the project we target. We do so by providing the app helper, which already identifies the project.
• Since Cloud function instances are region-specific, we specify which instance region we target. If omitted, the client SDK targets us-central1, which errors if no instance runs there:

const functions = getFunctions(app, "europe-west1")

get a handle over the Callable function

We provide the function's name and the type arguments:

const requestPokemonCF = httpsCallable<ReqData, ResData>(functions, "requestPokemon")

invoke and handle the result

• The request data, if any, is of type ReqData in our example.
• The returned value is of type HttpsCallableResult<ResData>, which is a container over the actual data, found in the data property, of type ResData in our example:

const result = await requestPokemonCF({ number: 151 })
result.data // ResData