finto is a web server that emulates EC2 instance profile roles on a workstation through STS's assume role function. It was born as an experiment to ease local interaction with AWS services in a deeply-federated, role-based environment. finto ships with a basic API for moving between roles, and handles credentials caching and expiration. While running, finto provides credentials to EC2 instance profile providers. This provider is last in the default provider chain of each SDK. For more information, refer to the official documentation on EC2 instance profile roles and the standardized credentials interface.