Billing

Prepaid credit, charged per minute of sandbox runtime. No subscription, no seats, no minimum, and nothing to cancel.

How credit works

• Your account holds a balance in US dollars. Sandbox runtime draws it down; buying a credit pack tops it up.
• New accounts start with $5.00 of credit, no card required — about 56 hours of small runtime.
• Credit does not expire.
• Balances are tracked in millionths of a dollar, so a 40-second sandbox is charged for 40 seconds, not rounded up to something bigger.

Check the balance at any time:

curl -sS https://sandbox-as-a-service.com/v1/account -H "Authorization: Bearer $AAS_API_KEY" | jq .balance_usd

What it costs

The rate is per hour of wall-clock runtime, per sandbox, and depends only on size. A small running for ten minutes costs $0.015; a large running for the full 1440-minute maximum costs $13.20.

What is billed

The meter starts when the sandbox becomes ready — the moment ready_at is stamped and the create call returns — and stops when it is destroyed. Charges accrue continuously and are written to your ledger about once a minute, with a final settlement at teardown, so the balance you see is never more than a minute behind reality.

The practical consequence: an idle sandbox costs the same as a busy one. The single biggest thing you can do for your bill is destroy sandboxes as soon as the work is done rather than letting them idle until they expire.

Running out of credit

The balance never goes negative — you cannot end up owing money. Instead:

• Creating a sandbox requires a small minimum balance (roughly five minutes of small runtime). Below that, POST /v1/sandboxes returns 402 with error.type: "insufficient_credits".
• Executing a command requires a balance above zero. At zero, exec returns the same 402.
• When the balance reaches zero while sandboxes are running, they are destroyed automatically within about a minute. Work in progress is lost, along with anything in the filesystem. This is the platform's protection against unbounded spend, and it is not gentle.

Watch the balance from your own code and top up before it bites:

import os
import requests

API = "https://sandbox-as-a-service.com/v1"
HEADERS = {"Authorization": f"Bearer {os.environ['AAS_API_KEY']}"}

def assert_enough_credit(minutes_needed, size="small"):
    """Fail fast instead of having a sandbox killed halfway through a job."""
    account = requests.get(f"{API}/account", headers=HEADERS, timeout=30).json()
    rate_per_hour = account["pricing_usd_per_hour"][size]
    needed = rate_per_hour * (minutes_needed / 60) * 1.5   # 50% headroom
    if account["balance_usd"] < needed:
        raise RuntimeError(
            f"balance ${account['balance_usd']:.4f} is below the ${needed:.4f} "
            f"needed for {minutes_needed} min of {size} runtime"
        )

assert_enough_credit(minutes_needed=45)

# Spend and runtime over the last 30 days
curl -sS "https://sandbox-as-a-service.com/v1/usage?days=30" -H "Authorization: Bearer $AAS_API_KEY" | jq

# {
#   "object": "usage",
#   "period_days": 30,
#   "balance_usd": 8.42,
#   "spent_usd": 2.58,
#   "added_usd": 10.00,
#   "sandboxes_created": 61,
#   "runtime_minutes": 3096
# }

Buying credit

Top up in Dashboard → Billing. Payment is handled by Stripe; card details never touch our servers. Credit lands on your balance as soon as the payment is confirmed, and each purchase is written to your ledger.

Purchases are one-off. There is no recurring charge and no auto-top-up, so a runaway job can never bill your card repeatedly — it can only spend the credit you have already bought.

Invoices and receipts

• Stripe emails a receipt for every purchase to the address on your account.
• The billing portal, linked from Dashboard → Billing, holds your payment history and invoices.
• Your credit ledger — every top-up and every usage charge, with the sandbox id it belongs to — is in the dashboard and via GET /v1/usage in summary form.

Cost control checklist

Deleting your account destroys every running sandbox and revokes every key. Remaining credit is forfeited, so spend it first.