Apache ShenYu is an open-source API gateway written in Java. The project describes it as an extensible, multi-protocol gateway that handles HTTP, Dubbo, gRPC, WebSocket and MQTT services, so that both REST APIs and RPC services can sit behind it. The software is offered as a download on the project website and runs on the organisation's own infrastructure. It can therefore serve as an open alternative to commercial API gateways.
ShenYu is licensed under the Apache License 2.0 and is developed within the Apache Software Foundation, a US 501(c)(3) nonprofit. The legal entity behind the project is therefore subject to US law. The source code is open, so a European organisation can decide where its traffic is processed and which version it runs. That control over the software and the infrastructure applies even though the foundation is based in the United States.