Pay-As-You-Go (PAYG)
Pay-As-You-Go allows you to use the Apertis API without a subscription by paying for what you use. This guide explains how PAYG works and how to manage it effectively.
Overview
PAYG is a flexible billing model where you:
- Add funds to your account balance
- Use the API as needed
- Pay per usage based on actual consumption
Add Funds → Make Requests → Deduct from Balance → Top Up When Low
PAYG vs. Subscription
| Feature | PAYG | Subscription |
|---|---|---|
| Commitment | None | Monthly/Yearly |
| Pricing | Standard rates | Discounted rates |
| Quota Reset | Never (balance-based) | Monthly cycle |
| Best For | Variable usage | Predictable usage |
| Minimum | $5 | Plan price |
When to Use PAYG
- Testing phase - Evaluating the platform
- Sporadic usage - Occasional API calls
- Unpredictable volume - Usage varies significantly
- Budget flexibility - Pay only for what you use
When to Use Subscription
- Regular usage - Consistent monthly volume
- Cost savings - Lower per-token rates
- Budgeting - Fixed monthly costs
- High volume - Heavy API usage
Adding Funds
Payment Methods
| Method | Availability | Processing |
|---|---|---|
| Credit/Debit Card | Global | Instant |
All payments are securely processed through Stripe.
Top-Up Process
- Log in to Dashboard
- Go to Billing → Add Funds
- Select amount
- Choose payment method
- Complete payment
Minimum Top-Up
| Method | Minimum |
|---|---|
| Credit Card | $5 |
PAYG Pricing
PAYG uses standard pricing per token based on the model used. For current model pricing, please visit the Models page.
Cost Calculation
Cost = (Input Tokens × Input Rate) + (Output Tokens × Output Rate)
PAYG Fallback for Subscriptions
Subscription users can enable PAYG as a fallback when subscription quota is exhausted.
How It Works
Request → Check Subscription Quota
↓
Quota Available? → Yes → Use Subscription Quota
↓ No
PAYG Enabled? → Yes → Use Account Balance
↓ No
Return 402 Error
Enabling PAYG Fallback
- Go to Billing → Subscription
- Find PAYG Fallback section
- Toggle Enable PAYG Fallback
- Set Spending Limit (optional)
- Save changes
Spending Limits
Set a maximum PAYG spending per billing cycle:
| Setting | Effect |
|---|---|
| No limit | Use balance until exhausted |
| $50/cycle | Max $50 PAYG per month |
| $0 | PAYG disabled (same as off) |
Hybrid Billing
When a request spans both subscription quota and PAYG:
Example: 100 quota remaining, request needs 150
Subscription pays: 100 (remaining quota)
PAYG pays: 50 (overflow)
Total request: 150 ✓
Auto Top-Up
Automatically add funds when balance drops below a threshold.
Configuration
| Setting | Description |
|---|---|
| Enable | Turn on auto top-up |
| Threshold | Balance level to trigger |
| Amount | Amount to add each time |
| Payment Method | Card to charge |
Example Setup
Threshold: $10
Amount: $50
When balance drops below $10:
→ Automatically charge $50 to saved card
→ New balance: current + $50
Setting Up Auto Top-Up
- Go to Billing → Payment Methods
- Add or select a payment method
- Go to Auto Top-Up settings
- Enable and configure threshold/amount
- Save
Best Practices
| Scenario | Threshold | Amount |
|---|---|---|
| Light usage | $5 | $20 |
| Regular usage | $20 | $50 |
| Heavy usage | $50 | $100 |
| Production | $100 | $200 |
Monitoring PAYG Usage
Dashboard Views
- Balance Overview - Current balance and recent transactions
- Usage Graph - Daily/weekly/monthly spending trends
- Transaction History - Detailed transaction log
API Access
Check balance programmatically:
import requests
response = requests.get(
"https://api.apertis.ai/api/user/self",
headers={"Authorization": "Bearer sk-your-api-key"}
)
user_info = response.json()
balance = user_info['data']['quota']
print(f"Current balance: ${balance / 500000:.2f}") # Convert from internal units
Low Balance Handling
Warning Levels
| Balance | Status | Recommendation |
|---|---|---|
| > $20 | Normal | Continue usage |
| $10-20 | Low | Consider top-up |
| $5-10 | Warning | Top up soon |
| < $5 | Critical | Top up immediately |
When Balance Exhausted
{
"error": {
"message": "Insufficient account balance",
"type": "billing_error",
"code": "insufficient_balance"
}
}
Recovery Steps
- Immediate: Add funds via dashboard
- Prevention: Enable auto top-up
- Monitoring: Set up low balance alerts
PAYG for Teams
Shared Balance
Team accounts share a common balance:
- All team members use the same balance
- Usage is tracked per API key
- Billing goes to account owner
Per-Key Limits
Control spending per team member:
- Create separate API keys for each member
- Set quota limits on each key
- Monitor usage per key
Cost Optimization
Model Selection
Choose cost-effective models for your use case:
| Use Case | Recommended | Cost |
|---|---|---|
| Simple chat | GPT-3.5 Turbo | $ |
| General tasks | GPT-4o-mini | $ |
| Complex reasoning | GPT-4o | $$ |
| Long context | Claude Sonnet 4.5 | $$ |
Prompt Optimization
Reduce costs by optimizing prompts:
# Expensive: Long, verbose prompt
prompt = """
I would like you to help me with the following task.
Please read the text below carefully and provide
a detailed summary of the main points...
"""
# Cheaper: Concise prompt
prompt = "Summarize the key points:"
Caching Strategy
Implement caching for repeated queries:
import hashlib
from functools import lru_cache
@lru_cache(maxsize=1000)
def cached_completion(prompt_hash):
# Only calls API if not cached
return client.chat.completions.create(...)
Set Max Tokens
Limit response length to control costs:
response = client.chat.completions.create(
model="gpt-4.1",
messages=[...],
max_tokens=500 # Limit output length
)
Billing Statements
Viewing Statements
- Go to Billing → Statements
- Select month
- View or download PDF
Statement Contents
- Beginning balance
- Top-ups during period
- Usage breakdown by model
- Ending balance
- Transaction details
Refunds
Refund Policy
- Unused balance is generally non-refundable
- Contact support for exceptional circumstances
- Refunds processed to original payment method
Requesting a Refund
- Contact support at [email protected]
- Provide account email and reason
- Allow 5-7 business days for review
FAQ
Can I switch from PAYG to subscription?
Yes, you can subscribe at any time. Your PAYG balance remains available for fallback usage.
What happens to unused PAYG balance?
Balance never expires and remains available until used.
Can I get invoices for PAYG purchases?
Yes, invoices are available in the Billing section for all top-ups.
Is there a minimum balance required?
No minimum balance is required, but we recommend maintaining at least $5 for uninterrupted service.
Related Topics
- Subscription Plans - Compare with subscriptions
- Quota Management - Understanding quota
- Rate Limits - Request limits
- API Keys - Key management