Turn usage into a customer budget

Plans are allowances

A simple API's plans might look like this (example numbers):

An AI product would write the same table in credits:

Different unit. Same structure: who → how much → what happens at the limit.

What you build vs. what Vibe does

• You decide what the plans are and what a credit is worth.
• Vibe counts usage per customer, enforces it before each call, and keeps the record.
• Stripe takes payment when someone upgrades or buys more, and receives usage reports from UsageFlow when you connect it.

A plan can change what runs

A budget doesn't have to be a single cliff. Your app asks for the same model on every call. The policy decides what actually runs:

Free  → cheaper model, capped output
Pro   → claude-sonnet-5
At 0  → blocked, upgrade prompt

The application code stays the same. Only the policy changes.

Where the money happens

Blocking is the moment a customer feels the limit. That's the right moment to show them an upgrade. Free hits its cap, and Pro is one click away.

Policy → usage → budget → runtime → billing

That's the whole model in five words:

1. Policy: what is this customer allowed to do?
2. Usage: how much have they used?
3. Budget: how much can they use?
4. Runtime: should this request run?
5. Billing: do they need to buy more?

A production API can already walk through the first four.

FAQ