There are some hackspaces in this world. The Space API was developed to exchange information about hackspaces in a standardized way. This API contains data about the hackspace such as whether the door is currently open for visitors and guests or not.
As a modern maker and hackspace the Toolbox is of course included and shows not only on the website if the hackspace is open, but also via Space API.
On GitHub you can find a list of JSON files provided by the hackspaces. Information about the Toolbox can be found here:
In the Toolbox itself there is a switch to change the status of the hackspace to open and closed. The git to the self-made server backend can be found on github.com/see-base/spaceapi-server.
The source code of the switch itself is on gitlab.com/ToolboxBodensee/webseite/spacebutton.
And of course there is an IRC bot to retrieve or change the space status. This can be found in the channel #see-base on Hackint and as source code in the git.
The Space API is also triggered by a newly installed door control and the status can be retreived via the internal Slack channel.