This is legal. See Teller API. Venmo will most likely lose if they take these devs to court based on precedent.
I don't like this trend of small time OSS devs being berated about legal bullying from megacorps, meanwhile handsomely VC-funded businesses get congratulated with legal help. We should be berating these companies of not releasing the APIs that people want to use!
We're in an age of AI, built atop agents, agents built atop APIs. APIs were the promise of Web 2.0, a promise being ripped away from us more and more by the day by these megacorps.
There should be a SPECIFIC legal funds/OSS unions protecting these Adversarial Interoperability projects and their maintainers from legal threat harassment by megacorps.
Just in the last 2 years we've had multiple near/passed-trillion dollar companies sending legal threats to OSS devs who have to fight them off on their own - one of them 15 years old.
Thank you alanalanlu and richardyhz for this project. Godspeed! And screw Venmo if they dare go after these two maintainers and their project!