An API gateway is a management tool that sits between a client and a collection of backend services. It acts as a reverse proxy to accept all application programming interface (API) calls, aggregate the various services required to fulfill them, and return the appropriate result. APIgateways can enforce policies such as rate limiting and authentication to prevent unauthorized access, making it an effective solution to prevent unauthorized API key sharing. By managing APIs at the gateway level, organizations can ensure that API keys are used as intended and are not shared or misused, addressing the need for secure management of API keys​​.