Talk to an AI agent, build a cart, and check out with PayPal sandbox.
Built for the PayPal AI Hackathon: Build what's next with PayPal and AI.
Tell the agent what you want — "a gift for my girlfriend under $100", "desk setup essentials under $60" — and it picks from the store catalog, builds your cart, and takes you through a real PayPal sandbox checkout. Captured orders land in an AG Grid order history.
You ──natural language──▶ AI agent ──structured cart──▶ Your cart (AG Grid, editable)
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PayPal Orders API (sandbox)
create → approve → capture
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Order history (AG Grid)
- Agent (
/api/agent): an LLM parses your request against the product catalog and returns a full cart (OpenAI-compatible API; defaults to a free endpoint, no key required). If every LLM endpoint is unreachable, a catalog-grounded offline fallback builds the cart from local rules, so checkout demos never break. - Checkout (
/api/paypal/order,/api/paypal/capture): the server prices items from the catalog (client prices are never trusted), creates a PayPal order, and captures it after you approve in the sandbox flow. - Order history (
/api/orders): captured sandbox payments are stored locally and displayed in AG Grid.
- Next.js 16 (App Router, TypeScript, Tailwind CSS 4)
- PayPal JavaScript SDK + Orders API v2 (sandbox)
- AG Grid 36 (cart editing + order history)
- Any OpenAI-compatible LLM (defaults to
text.pollinations.ai— zero setup)
git clone <repo-url> agentic-cart
cd agentic-cart
npm install
cp .env.example .env.local # then fill in your values (see below)
npm run devOpen http://localhost:3000 and ask the agent to build your cart.
| Variable | Required | Where to get it |
|---|---|---|
PAYPAL_CLIENT_ID |
yes | developer.paypal.com → Apps & Credentials → your sandbox app |
PAYPAL_CLIENT_SECRET |
yes | same page (click Show) |
NEXT_PUBLIC_PAYPAL_CLIENT_ID |
yes | same as PAYPAL_CLIENT_ID (public, safe to expose) |
LLM_API_URL |
no | OpenAI-compatible endpoint. Default: https://text.pollinations.ai/openai (works without a key) |
LLM_API_KEY |
no | only if your LLM endpoint needs one |
LLM_MODEL |
no | model name for your endpoint (default openai) |
- Create a free account at developer.paypal.com.
- Create a REST App in Apps & Credentials → Sandbox (or use the default app).
- Copy the Client ID and Secret into
.env.local. - Pay with the sandbox test card on the PayPal sheet, or log in with a sandbox buyer account (Testing Tools → sandbox accounts).
- LLM via OpenAI-compatible API — the agent that turns natural language into a validated cart (catalog-grounded, budget-aware).
- Built and iterated with AI coding assistants.
- Cart: inline quantity editing with validation (1–20), live line totals, remove actions.
- Order history: captured sandbox payments with status chips and PayPal deep links.
MIT — see LICENSE.