# Spending controls

Your shared balance funds usage. Key spending limits and selected pools provide separate controls over access and cost.

Source: https://zrelay.net/docs/capabilities/spending-controls/

## Account balance

Add prepaid USD balance in the account portal. All keys share the account balance, but route eligibility still depends on the key’s provider and pool. Balance is for API usage and cannot be withdrawn as cash.

## Per-key limits

Set and review spending limits in the portal. Use separate keys for separate applications so you can revoke access and review usage independently. The account’s total balance is not the same as one key’s remaining allowance.

## Application budgets

Set output token budgets, agent iteration limits and bounded concurrency. Monitor confirmed charges and handle 402 responses without an automatic retry loop. A request in progress can finish using the remaining balance; excess beyond that balance is covered by Zrelay.

## Monitor usage

Read [balance and request history](https://zrelay.net/docs/md/api/credits.md) and use the portal’s Usage section. Availability and limits are not a contractual uptime guarantee.