Documentation
FAQ: How do balance, quota, and key budgets work? in the NexoRouter documentation.
FAQ: How do balance, quota, and key budgets work?
NexoRouter uses prepaid balance. API keys can either draw from the account balance or be constrained by a hard key budget.
Core concepts
| Concept | Meaning |
|---|---|
| Account balance | Shared prepaid value available to the account. |
| Quota | Internal accounting unit. Public docs use 1 USD = 500000 quota. |
| Key budget | Optional cap for one API key. Useful for tools, tests, and agents. |
| Model cost | Cost depends on selected model, input tokens, output tokens, and provider pricing. |
| Usage Logs | Source for request-level model, token, cost, latency, status, and request ID data. |
When requests fail
insufficient_quota: account balance or key budget cannot cover the request.model_not_found: model scope may exclude the selected model.request_too_large: lowering budget will not fix it; reduce input size.
Practical setup
Use a low key budget for new tools. After verification, create a separate production key with explicit scope and monitoring.