When companies distribute Claude, GPT or Gemini APIs internally or to customers, model price is only one part of the problem. The boring infrastructure layer matters more than most teams expect. Budget caps Each tenant, team or customer should have a hard budget. Usage should be controlled before the request is completed, not only reviewed at the end of the month. Model permissions Not every workflow needs the most expensive model. Model access should be tied to use case, tenant and budget. Token limits Long prompts and long outputs can create cost spikes even when request volume is low. Context length and output tokens need limits. Rate limits Bad scripts, loops or abuse can drain budgets quickly. Rate limiting belongs in the gateway layer, not only in application code. Multi-key failover If one key hits limits or one provider becomes unstable, the gateway should be able to route traffic to a fallback chain.…