From the MTurk blog: https://blog.mturk.com/more-flexibility-for-mturk-requesters-who-use-the-mturk-api-38c91eda3808 "Amazon Mechanical Turk (MTurk) is a marketplace for work that requires human intelligence. We provide Requesters access to an on-demand scalable workforce. For Requesters who seek to integrate directly with MTurk, we offer a full Application Programming Interface (API) including Software Development Kits (SDKs) and a simulated Sandbox environment for testing. Today, MTurk is pleased to announce improvements to the onboarding experience for new Requesters who wish to use the MTurk API. We refreshed the Developer Getting Started page on the MTurk Requester Website with easy-to-follow steps to get started. We also added flexibility for developers to choose the Amazon Web Services (AWS) account they wish to use with MTurk."