Metered billing for an AI content creator app

Get started with usage based billing for your OpenAI based apps!

This project generates marketing content using OpenAI, implements metered pricing model, checks for feature access based on their current subscription, reports usage of a feature, manages subscription and more using Tier.

Demo

• https://tier-vercel-openai.vercel.app/

Features

• NextJS 13 /app dir
• AI content generation using OpenAI
• Pricing using Tier and Stripe.
  • Pricing model using Tier Model Builder
  • Subscriptions and Checkout
  • Feature access and upsells
  • Reporting usage of a feature
  • Pricing table
  • Customer billing portal
• Authentication using Auth.js
• ORM using Prisma
• Database on Vercel Postgres (Default) / Planetscale / Supabase

Why Tier?

Tier decouples billing, metering, and access checks from your application code. With it, you can conveniently establish new pricing models without needing to restructure your app or concern yourself with grandfathering or breaking changes.

Running locally

1. Install dependencies

npm i

1. Copy .env.example to .env.local and update the variables.

cp .env.example .env.local

1. Run the project locally

npm run dev

Tier Pricing Model

• Model Builder - https://model.tier.run/clkkv3fv93bbko972m4w3x9o8

You can clone the pricing model from the above links and make it your own. You can sync it with your Stripe "Test Mode" for both your dev and staging environments. You can also push this model to prod as shown below, by making use of the Tier CLI using this command where you use the model builder link and set a environment variable called STRIPE_API_KEY which should be a restricted key generated will all permissions in your Stripe live mode. You can find restricted keys at Developers > API Keys > Restricted Keys

tier --live push <https://models.tier.run/XXXXXXXX>

Environment variables

We have considerably reduced the number of environment variables in the project to make it easier for you to get started. This is an exhaustive list of all the environment variables in the project

1. App: NEXT_PUBLIC_APP_URL - The is the URL of your application, if you are in the middle of using our deploy button for Vercel, you can open vercel dashboard in another window and visit https://vercel.com/jerric-tier/project-name/settings/domains by replacing project-name with yours, make sure to append https:// to your domain. In local dev mode, you can set this variable in env.local / env.development and give it this value http://localhost:3000.
2. Auth: NEXTAUTH_URL - Used by Auth.JS - When deploying to vercel you do not have to set this value, but when you develop you can set this as http://localhost:3000. Find more details here.
3. Auth: NEXTAUTH_SECRET - Used by Auth.JS - Used to encrypt JWT and you can easily generate a secret using openssl rand -base64 32. Find more details here.
4. Github OAuth: GITHUB_CLIENT_ID and GITHUB_CLIENT_SECRET - Both Client ID and Client Secret of Github App can be generated at your Github Developer Settings page and you can read the step-by-step directions here. You can provide your NEXT_PUBLIC_APP_URL as the Homepage URL and append /api/auth/callback/github for the callback URL
5. Tier: TIER_BASE_URL & TIER_API_KEY - You can set your TIER_BASE_URL variable as https://api.tier.run default value in all your environments and TIER_API_KEY is your Stripe secret key. You can follow the steps in our docs to sync your pricing model with your Stripe account.
6. OpenAI: OPENAI_API_KEY - Get your OpenAI API key from OpenAI User Settings
7. Vercel Storage: POSTGRES_PRISMA_URL & POSTGRES_URL_NON_POOLING - You will only need these two variables after you have setup your database as we are using Prisma. You can find more details here.

Powered by

This example is powered by the following services:

• Tier (Subscriptions and Pricing)
• OpenAI (AI API)
• Vercel (Hosting NextJS)
• Auth.js (Auth)
• Vercel Postgres (default) / Supabase / Planetscale (Database)
• Stripe (Payments)
• Infisical (Secrets)

License

License under the MIT license.