We followed the process with the IRS, doing a bunch of verification as you said, which gave us access to the API docs. We're only part-way through the full process of becoming an Online Provider per https://www.irs.gov/pub/irs-pdf/p3112.pdf
I wish it were simpler. I get why the IRS wants to verify who is submitting tax data to them, though.
I've been transferring into rust consulting but i used to help companies get registered on various federal contracts, agreements, DUNS, SAM ETC.
I don't know too much about the specific program but after skimming the pub you posted i may be able to provide some value. I'd be willing to help you out for free as I really like what you guys are doing. Feel free to email me at lrhoades at gsacontractpros.com if you're interested.
Nice. Will you open source the code and docs at all?
I do get why the irs wants to vet submitters in production but you can't even get the detailed info for development without going through the long verification process.
I wanted to do this since I have extensive experience in implementing SOAP clients and interfacing with ancient legacy systems so I am very interested in any public way to contribute
I was just about to suggest that rather than contract out for an end-user application that the IRS create a webservice and let people build front-ends for it. Too bad it's SOAP, but its not the end of the world. If you make you're app open source I'd contribute.
I wish it were simpler. I get why the IRS wants to verify who is submitting tax data to them, though.