The on-line API documentation explains the data that modules expect and return on their APIs. The associated list of endpoints will also assist.
Get help in the FOLIO Slack #learning-apis channel.
To connect to the APIs there are several software options:
curl
The Okapi Guide has detailed examples and explanations how to use APIs with command-line tool curl.
okapi-curl
The okapi-curl is a shell script that wraps curl.
Okapi CLI
The okapi-cli is a command-line interface written in Java.
OkapiClient
The OkapiCLI.py is a command-line interface written in Python.
Stripes CLI
The stripes-cli is a command-line interface written in JavaScript that can connect to back-end APIs and help front-end developers that use FOLIO’s User Interface framework Stripes.
Postman
The folio-api-tests Github repository contains Postman collections for the APIs of some FOLIO modules. Use them with Postman or Newman.
HTTPie
HTTPie has a command-line tool and also a user interface.