You're in the right place: this page is the entry point to the API Monetization 101 series.
You want to charge for your API. The hard part isn't the billing integration or the Stripe webhook. It's figuring out what to count, how to structure your plans, and what happens when a customer hits their limit.
This three-part series walks through the full stack of concepts behind API monetization, from what to count and how to structure plans to how to decide what to charge. Start here for the full picture.
- You're building an API product and want to charge for it
- You need to understand how metering, plans, and enforcement fit together
- You want a clear path from "I have an API" to "customers are paying me"
Zuplo API Monetization Beta
Zuplo's API monetization is in private beta. Register for early access and we'll reach out when you can try it.
Part 1: Metering, Features, and Enforcement
How API Metering, Features and Quota Enforcement Work →
Everything starts with counting. But "count API requests" is only the beginning. If you're wrapping an LLM, a 50-token response and a 4,000-token response shouldn't cost the same. If you're serving files, a 1KB JSON payload and a 500MB download aren't equal either.
This post covers the three common metering patterns (request counting, token metering, data transfer), how meters connect to features in your product catalog, and how enforcement works at the gateway level. It also breaks down the difference between hard and soft limits, and when to use each.
Start here if you're not sure what "metering" actually means in practice, or if you want to understand the enforcement layer that blocks requests before they reach your backend.
Part 2: Plans, Phases, and Rate Cards
API Pricing Plans, Phases, and Rate Cards Explained →
Meters track usage, but customers don't buy meters. They buy plans. This post covers how to structure what you're actually selling.
The key concept is the plan hierarchy: a plan contains phases, each phase contains rate cards, and rate cards tie features to prices and entitlements. This hierarchy lets you model things like "Pro plan with a 2-week trial" as one plan with two phases, not two plans stitched together.
The post walks through pricing models (flat fee, per-unit, graduated tiered, volume tiered, package), shows how to set up included usage with overage billing, and includes a complete JSON example of a plan with a free trial that converts to a paid tier.
Start here if you already understand metering and want to design your pricing structure.
Part 3: Use AI to Plan Your Pricing Strategy
Use AI to Plan Your API Pricing Strategy →
The hardest part of API monetization isn't the implementation. It's deciding what to charge. How many tiers? Per-request or per-token? What overage rate?
This post provides a ready-to-use LLM prompt that walks you through the key pricing decisions: what you meter, who your customers are, what your costs look like, and what your goals are. The output is a comparison table with specific tier recommendations and reasoning you can share with your team.
Start here if you have an API you want to monetize but haven't committed to a pricing model yet.
Reading Order
The series is designed to be read in order, but each post stands on its own.
If you're starting from scratch, read all three: Part 1: Metering, Features, and Enforcement gives you the foundation, Part 2: Plans, Phases, and Rate Cards gives you the structure, and Part 3: Use AI to Plan Your Pricing Strategy helps you figure out the actual numbers.
If you already know what you want to charge and just need to implement it, start with Part 1 and Part 2.
If you're still figuring out your pricing model, start with Part 3 and come back to Part 1 and Part 2 when you're ready.
Why Your Gateway Should Be the System of Record
Once you understand the concepts in this series, the next question is where to implement them. Most teams wire together Stripe, a separate metering service, webhook logic to sync billing state, and rate limiting at the gateway. When billing and the gateway are separate, you're always playing catch-up: a customer upgrades, Stripe fires a webhook, your backend processes it, your gateway eventually updates. In between, something breaks or gets enforced incorrectly.
The fix is putting metering and enforcement in the same place. When your API gateway is the system of record, it knows the current plan, tracks usage against it, and enforces limits in real time on every request.
Zuplo Monetization does exactly that: meters, features, plans, Stripe integration, and real-time enforcement in your gateway. API keys scope to plans automatically; usage is queryable for your dashboards. See the Rick & Morty demo for the full end-to-end flow.
Get Started
Zuplo Monetization is in private beta. If you're building an API product and want metering, plans, and enforcement in one place, register for early access.
Zuplo API Monetization Beta
Zuplo's API monetization is in private beta. Register for early access and we'll reach out when you can try it.
