Credit System Fincept uses a credit-based system where each API call consumes credits based on computational complexity. This guide explains how credits work, when they’re deducted, and how to manage your balance.
How Credits Work Credit as Currency Credits are the unit of payment for API calls:
Tier Credits per Request Computational Cost Free 0 Lightweight utilities Basic 1 Simple calculations Standard 2 Moderate complexity Pro 5 Advanced models & ML
Deduction Timing Credits are only deducted on successful requests. Failed requests cost nothing!
What Counts as Success? Credits Deducted (200 OK): { "success" : true , "data" : { "price" : 42.50 } }
No Credits Deducted (4xx/5xx errors): { "success" : false , "message" : "Invalid parameters" }
New User Credits Free Account Bonus Every registered account gets:
350 Credits that NEVER EXPIRE # Register curl -X POST https://finceptbackend.share.zrok.io/user/register \ -H "Content-Type: application/json" \ -d '{"username": "john", "email": "[email protected] ", "password": "Pass123!"}' # After verification: credit_balance = 350
What 350 credits get you:
Unlimited Free tier calls (0 credits each)
350 Basic tier calls (1 credit each)
175 Standard tier calls (2 credits each)
70 Pro tier calls (5 credits each)
Or any combination!
Guest Account Credits 50 Credits for 24-hour testing:curl -X POST https://finceptbackend.share.zrok.io/guest/create \ -H "Content-Type: application/json" \ -d '{"device_id": "test-device"}'
Guest credits expire after 24 hours and cannot be topped up . Register for permanent 350 credits!
Checking Your Balance View Current Balance curl https://finceptbackend.share.zrok.io/user/profile \ -H "X-API-Key: fk_user_your_key"
Response: { "success" : true , "data" : { "username" : "johndoe" , "credit_balance" : 284.5 , "account_type" : "free" } }
Usage History Track credit consumption over time:
curl https://finceptbackend.share.zrok.io/user/usage \ -H "X-API-Key: fk_user_your_key"
Response: { "success" : true , "data" : { "period" : "last_30_days" , "total_requests" : 127 , "total_credits_used" : 65.5 , "current_balance" : 284.5 , "endpoint_usage" : { "/quantlib/pricing/black-scholes" : { "count" : 45 , "credits" : 90 } } } }
Credit Deduction Logic Database-Level Protection Credits cannot go negative - system prevents overdraft:
# Internal logic (for reference) if user.credit_balance < required_credits: raise InsufficientCreditsError # Atomic deduction with floor at 0 user.credit_balance = max ( 0 , user.credit_balance - credits )
Insufficient Credits Error { "success" : false , "message" : "Insufficient credits" , "detail" : "Required: 5 credits, Available: 2 credits. Please purchase a new plan to continue." }
HTTP Status: 402 Payment RequiredRace Condition Protection Multiple simultaneous requests are handled safely:
Request A (5 credits) + Request B (5 credits) with balance = 7 credits Request A succeeds → Balance = 2 Request B fails (insufficient) → Balance stays 2
Credit Expiry Never Expire Free account signup credits (350)
One-time credit purchases
Unused subscription credits carry forward (if subscription active)
Monthly Expiry Subscription credits refresh monthly:
Jan 1: +500 credits (subscription) Jan 15: Used 200 credits → Balance = 300 Feb 1: Balance resets to 500 (Jan credits lost)
Mix subscriptions with one-time purchases: subscription for regular usage, one-time for overflow that never expires!
After Subscription Ends Active subscription: 500 credits/month ↓ Subscription expires ↓ Auto-downgrade to free tier: +350 credits (never expire)
Topping Up Credits Buy One-Time Credits curl -X POST https://finceptbackend.share.zrok.io/payment/checkout \ -H "X-API-Key: fk_user_your_key" \ -H "Content-Type: application/json" \ -d '{"plan_id": "credits_500"}'
View credit packages → Subscribe for Monthly Credits curl -X POST https://finceptbackend.share.zrok.io/payment/checkout \ -H "X-API-Key: fk_user_your_key" \ -H "Content-Type: application/json" \ -d '{"plan_id": "basic_monthly"}'
View subscription plans → Credit Optimization 1. Use Free Tier When Possible Many utility functions cost 0 credits:
# FREE - Check business day POST /quantlib/core/date/is-business-day # FREE - Parse date POST /quantlib/core/date/parse # 2 CREDITS - Price option POST /quantlib/pricing/black-scholes
2. Choose Right Tier Don’t overpay for simple operations:
Bad (5 credits): # Using Pro tier for simple mean POST /quantlib/risk/var # Overkill!
Good (1 credit): # Using Basic tier POST /quantlib/statistics/mean # Perfect!
3. Batch Operations Design workflows to minimize API calls:
Inefficient (10 credits): 5 separate calls × 2 credits = 10 credits
Efficient (2 credits): 1 call with batch parameters × 2 credits = 2 credits
4. Cache Results Store frequently used results locally:
# Cache yield curve (2 credits once) curve = api.build_curve( ... ) cache.set( "yield_curve_2024" , curve, ttl = 3600 ) # Reuse for multiple bonds (0 extra credits) for bond in bonds: price = api.price_bond(bond, curve = cached_curve)
Transaction History View all credit movements:
curl https://finceptbackend.share.zrok.io/user/transactions \ -H "X-API-Key: fk_user_your_key"
Response: { "success" : true , "data" : { "transactions" : [ { "id" : 123 , "transaction_id" : "txn_abc123" , "amount_inr" : 4.99 , "credits_purchased" : 500 , "status" : "completed" , "created_at" : "2024-01-15T10:30:00Z" } ] } }
FAQs
Do credits rollover to next month?
Subscription credits : No, they reset monthlyOne-time credits : Yes, they never expire
What happens if I run out?
API calls fail with 402 error. Purchase more credits to continue.
Are failed requests charged?
No! Only successful requests (200 OK) consume credits.
Can I get a refund for unused credits?
No, credits are non-refundable once purchased.
How do I track credit usage?
Use /user/usage endpoint for detailed analytics by endpoint and time period.
No, the system prevents negative balances. Requests fail if insufficient credits.
Do enterprise accounts use credits?
Enterprise accounts have unlimited access without credit deduction (custom pricing).
Next Steps 