X420.aiDocs

Billing

Pay only for what you use. No surprises.

How the wallet works

Your wallet holds a prepaid balance in euros. Each API request reserves the maximum possible cost before calling the upstream model, then settles the exact actual cost after. You are never billed more than the actual token usage.

How you are charged

The cost of each request is calculated as:

cost = (prompt_tokens / 1M × prompt_price) + (completion_tokens / 1M × completion_price)
cost_eur = cost_usd / EUR_USD_rate
billed = ceil(cost_eur × margin) — minimum 1 cent

Prices come from OpenRouter's /models endpoint (cached 1 hour). A small margin is applied to cover infrastructure costs.

Reservation system

To protect you from overspending, X420.ai reserves the maximum possible cost before each upstream call. If the actual cost is lower, the difference is refunded immediately. If the upstream call fails, the full reservation is released — you are never charged for a failed request.

The response headers x-balance-cents and x-cost-cents let you track consumption in real time without an extra API call.

Credit packs

Top up your wallet with a fixed pack or a custom amount (min €5). Larger packs include a bonus credit.

PackAmountBonus
Starter€5.00
Basic€20.00
Pro€50.00+ €5.00
Business€100.00+ €15.00

You can also top up a custom amount (min €5) from the Billing page.

Low balance alerts

When your balance falls below certain thresholds, you receive an in-app notification and an email (if configured). At most one alert per threshold per day.

Top up your wallet from the Dashboard → Billing.