Payments: what the agents install

Install share by product

Install share counts the product each answer installed first. Mentioned counts answers that named it anywhere, picked or not. The band is a 95% Wilson interval: with samples this small, products a few points apart are tied.

Prompt by prompt

Each chip is one answer (2 samples per model). None means the model built it by hand or didn't choose.

1. “Add monthly and yearly subscriptions to my Next.js SaaS, with a checkout page and webhooks. Give the exact install commands and the key code.”

   ClaudeStripeStripe
   GPTStripeStripe
   GeminiStripeStripe

2. “My FastAPI app sells a one-time $19 digital report. Add checkout and mark the order paid after payment. Give the exact install commands and the key code.”

   ClaudeStripeStripe
   GPTStripeStripe
   GeminiStripeStripe

3. “Add usage-based billing to my Node API: charge customers per 1,000 API calls each month. Give the exact install commands and the key code.”

   ClaudeStripeStripe
   GPTStripeStripe
   GeminiStripeStripe

4. “I'm a solo developer selling software worldwide and I don't want to deal with sales tax. Add payments to my Next.js app. Give the exact install commands and the key code.”

   ClaudePaddlePaddle
   GPTPaddlePaddle
   GeminiLemon SqueezyLemon Squeezy

5. “Add a pricing page with three plans, a customer billing portal and a webhook handler to my Remix app. Give the exact install commands and the key code.”

   ClaudeStripeStripe
   GPTStripeStripe
   GeminiStripeStripe

What the models wrote

### Install Commands

```bash
pip install fastapi uvicorn stripe
```

### Key Code

You will need a Stripe account. Set your `STRIPE_SECRET_KEY` and `STRIPE_WEBHOOK_SECRET` in your environment.

```python
import os
import stripe
from fastapi import FastAPI, Request, HTTPException, Header
from fastapi.responses import HTMLResponse, RedirectResponse

app = FastAPI()

# Initialize Stripe
stripe.api_key = os.environ.get(

e alone doesn't do that for you. I'll use Paddle below; the pattern is nearly identical for the others.

## 1. Install

```bash
npm install @paddle/paddle-js @paddle/paddle-node-sdk
```

## 2. Env vars (`.env.local`)

```
NEXT_PUBLIC_PADDLE_CLIENT_TOKEN=live_xxx   # or test_xxx for sandbox
NEXT_PUBLIC_PADDLE_ENV=sandbox             # or production
NEXT_PUBLIC_PADDLE_PRICE_ID=pri_xxx
PADDLE_API_KEY=pdl_xxx
PADDLE_WEBH

)**. **Lemon Squeezy** is the easiest MoR to integrate with Next.js.

### 1. Install the SDK
Run this in your terminal:
```bash
npm install @lemonsqueezy/lemonsqueezy.js
```

### 2. Environment Variables (`.env.local`)
Get these from your Lemon Squeezy dashboard:
```env
LEMONSQUEEZY_API_KEY=your_api_key
LEMONSQUEEZY_STORE_ID=your_store_id
LEMONSQUEEZY_WEBHOOK_SECRET=your_custom_secret_string
```

### 3. Create a Chec

Questions