Vehicle-to-everything (V2X) is on the verge of being integrated as an integral part of modern vehicles. However, the battle for the final V2X radio technology is still not decided, and the available message standards are complex, hindering research and development. Hence, in our work, we provide a toolbox for early-stage development within V2X, called vehicle communication platform to anything (vehicleCAPTAIN). The vehicleCAPTAIN toolbox comprises (i) a set of software that mitigates the need to adapt for different V2X hardware vendors by decoupling and simplifying implementation, (ii) a set of libraries that supports encoding and decoding of messages, and (iii) a set of software bindings to enable development with ROS2. All software is provided as free and open source (FOSS). Within this work, we prove the functionality of the toolbox with classic end-to-end tests, as well as Qosium, a quality-of-service testing application. Finally, we highlight the applicability and benefits of the vehicleCAPTAIN toolbox for early-stage V2X research and development.