The Wayback Machine - https://web.archive.org/web/20160617151040/https://dev.twitter.com/ads/ads-api-sandbox

Ads API Sandbox

The sandbox is an environment for you to test and build your Ads API implementation.

Campaigns created via the sandbox will not be served to users and test records for objects such as funding instruments can be created dynamically.

Using the sandbox is as simple as calling the appropriate hostname of ads-api-sandbox.twitter.com but it also contains some unique functionality found only in the sandbox.

When making an initial request to GET accounts in the sandbox, an account record will be generated for you from which you can perform the remainder of your operations. It is also possible to create and manage multiple accounts and funding instruments within the sandbox.

Sandbox-Only Endpoint List: