The following are common methods you will want to call in your front end templates:
craft.consume.getAllClients()#Returns a collection of Client objects.
craft.consume.getAllEnabledClients()#Returns a collection of enabled Client objects.
craft.consume.getAllConfiguredClients()#Returns a collection of configured Client objects.
craft.consume.getClientById(id)#Returns a Client object by its ID.
craft.consume.getClientByHandle(handle)#Returns a Client object by its handle.
craft.consume.fetchData(client, method, uri, options)#Returns data from your client. See Fetching Data for further docs.
Available for Craft 4. Get it from the plugin store.