The bill arrives and nobody knows whose it is
Something that happens to almost every engineering team that ships AI:
Month one, the inference bill is $400. Nobody looks at it.
Month six, it's $14,000. Everybody looks at it. And here's the thing — you cannot tell where it came from.
Not because your finance team is bad at their job. Because the provider has no idea your company has teams. You gave them one API key. They gave you one number. There is nothing to break down.
So someone spends two weeks building log parsing to reverse-engineer attribution from request patterns. It half works. It is out of date immediately.
The actual fix is boring: stop distributing provider keys. Issue scoped keys per team from a layer that sits in front. Then attribution isn't a report you build — it's a property of the system. Every request already knows which team it belongs to, because the key does.
The same layer gets you a few other things you'll want by month six anyway:
— rotate a key without hunting through six repos — revoke a leaked one in seconds, no provider round-trip — fallback chains configured once instead of in every service — one place to put PII redaction, because otherwise there isn't one — an actual answer when an auditor asks who has access
None of this is about models. It's plumbing. But it's the plumbing that decides whether your AI spend is something you manage or something that happens to you.
If you want to see what the enterprise version looks like fully documented — deployment topologies, audit log fields, residency regions, the lot — it's here: https://nemorouter.ai/enterprise
Worth saying: if you're one team with one provider, ignore all of this. You don't need a routing layer. This only becomes real once there's a second team, and by then it's usually already a bit late.












