An Ocean marketplace application is a web app that lets people list data assets for sale (maybe free) and lets consumers buy those assets. To connect your marketplace with the Ocean network, you'll want to use one of the Squid libraries.
TODO: Expand the following:
Dev option 1: Fork Pleuston (serverless). Use the Docker Compose workflow that Pleuston devs use.
Dev option 2: Build a marketplace with a server-side and a web frontend. Use one of the Squid libraries.
Currently, there is no explicit example of how to do that, but there are examples of how to use squid-py, e.g. from IPython running in a Jupyter notebook.
See the Tutorials section.
You could even write an entirely server-side marketplace with a command-line interface, but let's not get carried away.
Note: There's also a squid-java library but it's currently not as full-featured as squid-js and squid-py.
## Aquarius
Aquarius is an application used by Marketplaces to store, update, read and delete metadata about assets. The Squid libraries all know how to talk to Aquarius, so you don't need to think about it or its API too much. You just need to make sure you have Aquarius running on a server somewhere.