We believe your AI costs should be transparent and predictable. Vellum passes through model provider costs at cost — we don't charge any margin or markup on token usage. When you spend $1 worth of credits on LLM tokens, that full dollar goes to the model provider. Our goal is to keep Vellum affordable and aligned with your actual usage, not to profit from the AI calls your assistant makes.
Vellum uses a prepaid credit balance: usage is deducted from your credits as you use the assistant. You can add credits anytime from the Billing page via Stripe Checkout. Applicable taxes may be added during checkout.
In the app, your Billing screen shows a Credit Balance plus a breakdown of settled and pending amounts:
The purchase and use of Vellum Credits is governed by Section 6 of our Terms of Service.
Vellum makes available certain features and functionalities within the Services, as designated by Vellum from time to time, that are accessible exclusively through the use of prepaid credits (“Vellum Credits”). These designated features and functionalities are referred to as “Credit-Eligible Features.” Credit-Eligible Features currently include inference, web search, and image creation. No alternative direct-payment method is available for Credit-Eligible Features.
You may fund your Vellum Credit balance (“Vellum Balance”) by purchasing Vellum Credits in increments of ten dollars ($10.00 USD), twenty-five dollars ($25.00 USD), fifty dollars ($50.00 USD), or one hundred dollars ($100.00 USD) through the payment methods made available in the Services, or at such other increments as determined by Vellum from time to time.
You can add credits from the app's Billing settings:
A minimum top-up amount can apply, and the app will show that minimum before checkout if your entered amount is too low.
When credits are exhausted, the app will show a “You've run out of credits” message with an Add Credits action that links you to Billing. Assistant actions that require paid usage will pause until credits are added.
Contact support at support@vellum.ai.