I started to play around with <a href="http://arangodb.com">ArangoDB</a> and used <a href="https://github.com/tariqdaouda/pyArango">Python</a> to get some data into my first database. Long story short: if you want to set your own key for the documents, do it on the document, not on the initialization data. EDIT: this is only true for the most recent version 1.3.1 release on pypi by the time of writing ((See <a href="https://github.com/tariqdaouda/pyArango/issues/118">conversation on github</a> for details)). <a href="https://blag.nullteilerfrei.de/2018/09/22/quick-tipp-for-first-time-users-of-the-arangodb-python-client/#more-4617" class="more-link">Read the longer story!</a>