The metaverse does not yet exist. Instead we have a series of fragmented virtual worlds that cannot communicate with each other. This is because we lack an open standard for interoperability. To resolve this challenge we propose auto, an open protocol for the autonomous metaverse. Auto allows developers to easily build interoperable virtual worlds using existing web technologies. These worlds are autonomous, meaning they are user-centric, self-sovereign, and permissionless – in the spirit of the original web. Auto allows for the emergence of the autoverse, an interoperable network of autonomous virtual worlds, owned and controlled by users, not corporations.