Credit System Overview
ModelStack uses a credit-based billing system. Credits are consumed based on token usage at per-model rates. There are two types of credits:
- Subscription credits — Auto-refill on a ~5-hour schedule with your plan
- Lifetime credits — Purchased separately, never expire
Subscription Credits
Every plan includes subscription credits that auto-refill on a regular schedule.
How Refills Work
- Credits refill on a ~5-hour schedule (several times per day)
- Each refill adds your plan’s credit amount (e.g., 250 credits for Starter)
- Credits are capped at a weekly maximum
- Credits reset after 7 days from your subscription start date
- Unused subscription credits don’t carry over past the weekly window
| Plan | Refill Amount | Refill Interval | Weekly Cap | RPM |
|---|
| Starter | 250 credits | Scheduled ~every 5 hours | 2,000 credits/week | 15 |
| Pro | 750 credits | Scheduled ~every 5 hours | 6,000 credits/week | 40 |
| Max | 1,600 credits | Scheduled ~every 5 hours | 12,800 credits/week | 60 |
Refills are scheduled; the platform aligns refill runs to a consistent ~5-hour cadence.
Example
With the Starter plan ($20/mo):
- Every ~5 hours, 250 credits are scheduled
- Over a full week, up to 2,000 credits are available
- If you don’t use all credits from one refill period, they accumulate up to the weekly cap
Lifetime Credits
Lifetime credits are purchased separately as a one-time deposit. They never expire and remain in your account until used.
Purchase Options
| Amount |
|---|
| $10 |
| $25 |
| $50 |
| $100 |
| $250 |
| $500 |
Plan-Based Discounts
Subscribers receive discounts when consuming lifetime credits:
| Plan | Discount | You Pay |
|---|
| Starter | 20% off | 80% of base cost |
| Pro | 30% off | 70% of base cost |
| Max | 50% off | 50% of base cost |
The discount applies to consumption — you pay full price when purchasing credits, but each API call costs less against your lifetime balance.
Consumption Order
Credits are consumed in a specific order:
1. Subscription credits (consumed first, at base pricing)
↓
2. Lifetime credits (consumed second, with plan discount applied)
↓
3. No credits remaining → 402 error
- Subscription credits are always consumed first at base model pricing
- Once subscription credits are exhausted, lifetime credits are used with your plan’s discount rate applied
- When both balances reach zero, API calls return a
402 Insufficient Balance error
What Happens When Credits Run Out?
When both subscription and lifetime credits are exhausted:
- API calls fail with a 402 status code
- You can purchase more lifetime credits anytime from your dashboard
- Subscription credits will automatically refill at the next scheduled interval (~5 hours)
