Billing

Marble 2 Developer API usage is billed to the account that owns the API key's project. Balances, payments, and monthly spend limits are under Settings → Billing. Account usage is on the Usage page.

Credits and top-ups

Developer API tasks draw credits from the account balance. The current beta conversion is 1,000 credits per US dollar. Credits purchased for the account do not expire.

Account owners and billing owners can add credits manually or enable automatic recharge. Auto-recharge charges the account's default payment method when the balance falls below a configured threshold and restores it to the chosen balance.

The task rate card can change during beta. Use the current rate card shown in the platform when estimating task costs rather than embedding model prices in client code.

Projects and attribution

Create projects to separate credentials, assets, operations, and usage for different environments or products. Every API key is bound to one project, so usage is attributed without sending a project ID in each Developer API route.

Project isolation is useful even when one account funds all work:

• production and development can use different keys;
• teams can inspect their own usage;
• experiments can receive a tighter budget;
• a compromised key cannot access another project's resources.

Usage

The Usage page shows the credits the account spent over a date range, per day and grouped by task or project. Developer API usage can also be grouped by API key. Studio and Developer usage are shown separately. Select a day to see its breakdown. The numbers come from the billing provider's rated invoices, so they are what the account is charged. A finished task can take a few minutes to appear.

Set monthly spend limits

Account owners and billing owners can create a monthly USD spend limit for the entire account or for one project. Limits reset each calendar month.

When an enabled applicable limit reaches 100%, new Developer API tasks pause. Tasks already running are allowed to finish. Raising, disabling, or deleting the limit restores admission once the account also has sufficient credits.

Use an account-wide limit for the total safety ceiling, then add project limits for workloads that need independent guardrails. A project task must satisfy both limits when both apply.

Spend limits are guardrails, not exact real-time accounting boundaries. In-flight work and delayed usage observations can produce some variance.

Payment methods and invoices

The account uses one shared Stripe payment profile for API credit purchases, automatic recharge, and Marble Studio subscriptions. Account owners and billing owners can add a payment method, choose the default, open the Stripe customer portal, and review invoices from the billing page.

Do not put payment operations in an API integration. Billing administration uses the authenticated platform session and account permissions, not a World Labs API key.

When work is paused

If a task is rejected because the account is out of credits or a spend limit is reached, the response is 402 Payment Required with code set to CREDITS_UNAVAILABLE or SPEND_LIMIT_EXCEEDED:

1. Do not retry in a tight loop.
2. Check the API key's project limit and the account-wide limit.
3. Add credits or adjust the appropriate limit.
4. Retry the same logical submission with its original idempotency key.