In order to make my life easier, it probably needs to be doing important stuff.
You can't hide behind 'other apps are doing it too', if my 'important business account' or whatever gets banned from using your tool, I'd be upset at you.
How do you guarantee your uptime SLA if my account may get banned any second?
Most of the ones I've seen on github do not store the messages encrypted locally.
When evaluating these tools, check to see what they store unencrypted on disk. A quick search shows that only one seems to check the boxes:
https://github.com/adelaidasofia/whatsapp-mcp
However I haven't tested it. And it does phone home, you may want to disable that before running it.
If not, is this a solution using WhatsApp Web in the backend (like Baileys does)? If this is the case, how does your solution avoid getting blocked or banned? I used Baileys once in an MVP with only 7 users, and my agent got blocked really quickly after just a few days of using it. So I guess the official path is the only way to go?
Will be used to spam
A harder version of the clause, that only a specific interface be used, might be contrary to Free Software howeer, as it would infringe in the right to modify (the interface), but not the right to study the software.