You've set up your pricing page. Free, Pro, Business. All nicely laid out with their respective limits. But here's the uncomfortable question: are you actually enforcing those limits?
The Enforcement Gap
Most API businesses have a gap between what they promise and what they enforce. The pricing page says 150K requests, but the API happily serves 500K. The database has a "plan" column, but no code actually reads it at request time.
This happens for understandable reasons:
- Enforcement is hard. Rate limiting, quota tracking, and entitlement checks add complexity.
- Edge cases are everywhere. Upgrades mid-month, trial periods, grace periods after failed payments.
- Performance matters. Adding a database lookup to every request can tank your latency.
So teams punt. They'll "add enforcement later." Later never comes, and the honor system becomes the de facto pricing model.
The Cost of No Enforcement
Revenue Leakage
Your biggest "free" users are consuming resources that should be paid. One heavy free user can cost more in infrastructure than ten paying customers bring in revenue.
Unfair Advantage
Your paying customers are competing with freeloaders. The startup that pays $99/month gets the same service as the one gaming the free tier.
Scaling Problems
As you grow, the enforcement gap grows with you. By the time it's painful enough to fix, you have thousands of users expecting the current behavior.
Request-Time Validation
The solution is to validate entitlements at request time. Every request, every time:
- ✓ Check if the API key is valid
- ✓ Check what plan the key belongs to
- ✓ Check current usage against limits
- ✓ Return actionable information (remaining quota, reset time)
When you validate at request time, your pricing page becomes reality. Free users hit their limit and see an upgrade prompt. Pro users get exactly what they pay for.
The Performance Question
"Won't this slow down every request?" It's a fair concern. A naive implementation (querying your primary database on every request) will add latency.
But a purpose-built system can verify requests in single-digit milliseconds. At Holdify, our verify endpoint runs on edge infrastructure with P99 latency under 50ms. For most APIs, that's noise compared to the actual work of processing the request.
Beyond Rate Limiting
Enforcement isn't just about counting requests. Modern API monetization needs:
Feature flags
Does this key have access to the premium endpoint?
Usage tracking
Track exactly what was consumed for accurate invoicing
Audit trails
Who accessed what, when, and was it allowed?
Real-time sync
When someone upgrades, access should expand immediately
Getting Started
If you're running an API without enforcement, now is the time to fix it. The longer you wait, the harder the migration becomes.