Every developer at my company uses their Claude Code subscription on an EC2 dev box. Plenty of other tech companies do the same. Heck nowadays people even install Claude Code directly on production servers in data centers and use it as an ops tool. None of this is a problem. Fraud and abuse detection is a lot more sophisticated than just checking an IP range.

None of the LLM providers block professional use thus they must necessarily permit access from commercial IP ranges.

I have no idea how the resellers are doing it but an obvious starting point would be a cheap VPS node that routed each account to a unique semi-permanent IPv4 or IPv6/64. All the provider would see would be a regular account making a normal looking stream of requests from a stable datacenter IP address. Any given request stream would remain consistent (at least over a period of a few hours) because a reseller would take care not to split the session of a single user across multiple different accounts and not to interleave the active sessions of multiple users on a single account.

Detecting this would be extremely difficult because on a longer time frame it's perfectly normal for many distinct accounts to work on the same code base.

Wouldn’t it be funny if the same residential proxies allowing these labs to scrape the Internet is also what’s enabling these resellers?

Sorry for being a newb here but are you saying Anthropic blocks people from running claude code on datacenter ip ranges?

Or is the datacenter IP just one part of the picture?

I assume they use residential proxies (tunneling in the background of crappy Android games) for the "last" hop.

Nonsense. Many if not all legit Claude users are using Claude Code inside their Cloud servers. How else would you use it anyway? For just local dev? That's so 2000 and late bro.