Use API to create automated daily direct mail campaign

Well, I just need to pull from an API and populate mail merges to print. the more automated the better. possibly even set up on a server to pull everytime a new one hits and email the letter package to print and mail?

I am interested in this one: https://app.drillinginfo.com/direct/#/api/explorer/v2/respondents
(I will share credential with proper candidates)

these are filed daily, and each one has multiple "Respondents"
"RespondentAddress1": "333 W SHERIDAN AVE",
"RespondentAddress2": null,
"RespondentCity": "OKLAHOMA CITY",
"RespondentCompany": "DEVON ENERGY PRODUCTION CO LP",
"RespondentFirstName": null,
"RespondentId": 139025175,
"RespondentLastName": null,
"RespondentRemarks": null,
"RespondentState": "OK",
"RespondentZip": 73102,

I am looking for the program to take every Respondent and their info and put them all in a mail merge file of a Letter - that we can print every day and mail to people to market to them

Any entry that has RespondentCompany needs to be totally left off. Only those with RespondentFirstName and RespondentLastName will be used

This is an example that will need to be changed before, but my thought is each Respondent is a letter and they are emailed daily as one word document with all the letters to print. The merge fields would be: First Name, Last Name, Address1, Address2, City, State, Zip, County of Property(DICountyParishName). My thought is that we could set it up on Heroku or something similar to run and send the files every time a new order is filed

Curious to hear your thoughts on creating this