What are some alternatives?
Postman - Postman is the most efficient way to test, develop and document APIs.
Gravitee.io - Gravitee.io is a flexible, lightweight and an open source API management solution.
Apigee - Intelligent and complete API platform
Tyk - Tyk is an open-source API gateway and API management platform.
Django REST framework - Django REST framework is a toolkit for building web APIs.
WSO2 API Manager - WSO2 API Manager is a 100% open source enterprise-class solution that supports API publishing, lifecycle management, application development, access control, rate limiting and analytics in one cleanly integrated system.