After you create and configure the Developer key for your app (see detailed instructions here) you can get both the client_id and the deployment_id.

The client_id is the developer key; it's a numeric value that looks something like

32450000000000542. 

The deployment_id can be found in Settings | Apps | App Configurations by opening the settings menu for your app. It is an alphanumeric string that might look something like 10832:7db538f4ca75c02373788b2ac73869cf572b0b68