Spending Controls

Manage your AI agent spending with API key limits and balance monitoring.

API Key Limits

Each API key can have optional spending limits:

When a limit is hit, the tool call is rejected with a SPENDING_LIMIT_EXCEEDED error. No charges are incurred.

Setting Limits

1. Go to xpay.tools  → Account → API Keys
2. Click on a key to edit its limits
3. Set per-call, daily, and/or monthly limits
4. Save changes — limits take effect immediately

Balance Management

Checking Your Balance

• In the dashboard: Account → Billing shows your current balance
• Programmatically: Use the xpay_balance meta-tool through the master server
• In tool responses: Every billing receipt shows your remaining balance

Topping Up

Add credits at xpay.tools  → Account → Billing:

• Credit card — Instant top-up via Stripe
• Crypto — Send USDC on Base to your account wallet

Best Practices

1. Create per-project keys — Separate keys for each project or agent makes spending easy to track
2. Set conservative limits — Start with low limits and increase as you understand your usage patterns
3. Monitor the billing receipts — The Balance in each receipt helps you track spend in real-time
4. Use provider endpoints for predictable costs — When you connect directly to a provider, you know exactly which tools (and prices) are available