A major challenge in interconnecting billions of computing devices in the Internet of Things (IoT) is interoperability. One approach that is gaining momentum is the Web of Things, that uses web architecture and web standards as a framework for creating IoT applications. Two main protocols are used in the application layer of the Web of Things: HTTP and CoAP. This work presents the conception, design, and evaluation of an Interception Proxy for HTTP and CoAP interoperability. The proposed proxy preserves the organic nature of the Swarm, by allowing a transparent discovery and communication among devices. In this proposal, the proxy constitutes an independent entity that intercepts Swarm communications, and performs the mapping between HTTP and CoAP or vice versa, thus, extending the interaction capabilities of the network. The implementation is based on an existing library and the validation results show the correct functionality of the proxy and its ability of operating in Swarm scenarios.