To manage and pin the (sub)dependencies of the relay server we use pip-tools. We create two requirements files, one for the production environment (:code:requirements.txt) and one for the additional development requirements (:code:dev-requirements.txt). For the dev environment, you have to install both. The production dependencies are derived from the dependencies defined in To add new dependencies, add them to and then run :code:./compile-requirements. The development requirements are derived from To add new development dependencies, add them to this file and then rerun :code:./compile-requirements. To upgrade the dependencies in the created requirement files, check out the available options for pip-tools and pass them to the compile script. To update all dependencies, run :code:./ --upgrade.