In-depth guides for AI usage metering and pricing
Tutorials with full code. Implement per-user OpenAI tracking, atomic rate limits, freemium image generators, token-based pricing, and the reserve / commit / release pattern that keeps it all correct under load.
Each guide below is a complete walkthrough - code, schema, and reasoning - written for developers shipping AI products in production. If you find a missing topic, send a note to s.castellitti.dev@gmail.com.
How to track OpenAI API usage by user (with quotas, in real time)
Step-by-step guide to tracking OpenAI API usage per end-user with real-time quotas. Pure-TypeScript pattern using @vevee/sdk. Concurrency-safe, provider-agnostic, ten-minute integration.
7 min · GuideHow to implement per-user rate limits in your AI app
Per-user rate limits for AI apps need atomic enforcement, plan awareness, and refundable reservations. Here is the pattern that works under load - using @vevee/sdk and ~30 lines of code.
9 min · GuideHow to implement usage-based pricing for an AI product
Decide between per-token, per-action, and hybrid pricing. Implement quotas, refunds, and Stripe meter sync. Step-by-step with code, from a developer who has shipped all three models.
6 min · GuideThe reserve / commit / release pattern: atomic AI quota enforcement
Why naive AI usage metering breaks under concurrency, and the only correct pattern that fixes it. Reserve / commit / release explained, with full TypeScript example and the failure modes it prevents.
8 min · GuideHow to charge AI app users by token usage (with refunds and live balance)
Step-by-step: charge users for actual token consumption with pre-paid credits, post-paid invoicing, and a live balance display. Atomic reservations, accurate refunds, and Stripe meter sync.
10 min · GuideBuild a freemium image generator: end-to-end tutorial
Ship a freemium AI image generator with hard caps, upgrade prompts, real-time analytics, and a live "renders left" badge - using @vevee/sdk + your image provider of choice. Full code, ten-minute build.
12 min · GuideAdd cookieless traffic attribution to a Next.js app
Six copy-paste steps to attribute every signup and every order to the visit that brought it, with @vevee/sdk 1.14. The visit lives in browser memory, a server route forwards events with the secret key, and nothing is written to the device.
8 min · GuideSend revenue from your payment webhook to Vevee
Record paid orders and refunds with vevee.revenue.order and vevee.revenue.refund so every channel and campaign gets a revenue column. Covers amounts in minor units net of tax, idempotency on the provider id, refunds that arrive early, and a webhook that never fails because of analytics.
7 min · GuideBuild the two attribution funnels from JSON
Paste one JSON file into Vevee's funnel import to get a visit to signup funnel and a signup to paid funnel, both split by channel. Covers the split forms, step filters, units, and how to read the split table.
9 min · GuideTest attribution with fake traffic in test mode
Check a cookieless attribution setup before real visitors arrive: a probe script that hits every call once, a seed script that fills test mode with believable traffic and refuses anything but an sk_test_ key, and a cross-check of the visit funnel against the Traffic page.
Looking for shorter answers?
See the Q&A for one-page answers to specific questions, or the glossary for term definitions. For pattern overviews see the use cases.