The generation of code templates from REST API specifications is a common practice in industry. However, existing tools neglects the dependencies among input parameters (so called inter-parameter dependencies), extremelly common in practice and usually described in natural language. As a result, developers are responsible for implementing the corresponding validation logic manually, a tedious and errorprone process. In this paper, we present an approach for the automated generation of code for inter-parameter dependencies specified using the IDL4OAS extension. As a proof of concept, we present an extension of the popular openapi-generator tool ecosystem, automating the generation of Java and Python code for the management of inter-parameter dependencies in both, servers and clients. Preliminary results show the effectiveness of the approach in accelerating the development of APIs while making them potentially more reliable.