The SpaceAPI directory is a list of spaces that have the SpaceAPI implemented.
If your space is missing in the list, fork the repository, add your space and create a pull request in GitHub.
Find more information about the SpaceAPI on spaceapi.io.
Some tips for correct implementation see information about providing a endpoint.
If you want to use the spaceapi directory, you can find it hosted under https://directory.spaceapi.io/.