I have been working with Linux (Ubuntu, RedHat, Fedora, etc) scripting for 7 years and have developed strong scripting abilities.
Your job isn't fully detailed but I am assuming that you will be providing more details to whomever wins the bid.
I will start by testing the API endpoints to verify how they behave, then depending on the nature of the endpoints (FTP, HTTP, REST, SOAP) I will write a script that is able to gather the files from the endpoint(s) and store them in the desired location
It is not clear if this is a script that is to be run once for a specific task, or to be run regularly as part of a process - in that case I would recommend putting in retry logic to provide resilience against spurious and annoying network glitches.
If my proposal sounds promising to you, please contact me to discuss it further to see if we can agree to the requirements and scope of the project
Best Regards,
Matthew