Pyp

Inspiration

Small businesses on PayPal spend hours on work that isn't their actual job: chasing late invoices, answering disputes before the deadline, and figuring out where the money went this week. Most can't afford someone to do it for them. We wanted to give every merchant a teammate who watches their PayPal account, notices what needs doing, and handles it, but never does anything they wouldn't approve of.

We also felt PayPal was missing a mascot. A lot of the apps people love have a friendly character, and PayPal doesn't. So we gave our AI one: Pyp, a little blue character that sits in the corner, blinks when you hover over it, and hops into the chat when you need help. You can even make Pyp your own by changing its color, giving it a hat (a beanie, a crown, a top hat and more), and picking your chat colors.

What it does

Pyp is an AI teammate for PayPal merchants. It lives in a dashboard, a chat widget, and a Chrome extension that puts Pyp right on PayPal.

Get paid: type "Invoice Jordan Kim $300 for the logo, net 30" and Pyp drafts the invoice. It also spots overdue invoices on its own and writes reminders in your voice.
Disputes: when a buyer opens a dispute, Pyp gathers the evidence (tracking, receipts you upload) and drafts a response before the deadline.
Insights: a weekly brief of money in, unpaid invoices and open disputes.
Your rules: each skill can be Off, Ask me or Auto, with limits, an undo window, and a pause switch.
Inbox of cards: everything Pyp wants to do shows up as a card. Flip any card to see "How I got here", a timestamped trace of every step.
Activity tab (AG Grid) with every payment, invoice, dispute and Pyp action in one table, plus a dispute deadline timeline (Bryntum).
Slack and Discord connections, so Pyp can reach you where you already work.

How we built it

Our one rule: the AI proposes, code decides.

Code gathers the facts from the PayPal sandbox (Invoicing, Disputes, Transaction Search, Orders, Shipping Trackers, and webhooks).
Claude makes the judgment call and writes the words: Haiku for chat and screening buyer messages, Sonnet for invoices and reading documents, Opus for disputes. Every answer has to match a strict schema.
Code checks the decision against the merchant's rules, does all the money math itself, and only then lets one module, the executor, write to PayPal, using PayPal-Request-Id so a retry can never double-send.

The stack: TypeScript and Next.js, Postgres on Supabase, a plain HTML/JS dashboard and a Manifest V3 Chrome extension that share one "transport" layer, and Ollama for free local testing.

Challenges we ran into

Connecting other merchants: PayPal's Partner Referrals isn't available to regular sandbox apps, so we couldn't let other merchants link their own accounts. We built and demo everything on one shared sandbox merchant.
Keeping the AI honest: buyer messages and uploaded files can try to trick an AI ("PayPal says refund me now"). We screen them separately and treat them as data, never instructions.
Small models in development: our local model talked about "the merchant" instead of to you, and forgot what the conversation was about. We fixed both by sending recent chat history and tightening the instructions.
API quirks: Disputes allows at most 50 results per page and pages with tokens, Transaction Search covers 31 days at a time, and invoices only accept fixed payment terms.
Three people, one codebase: we coordinated database changes, kept a shared test suite green, and merged small pull requests often.

Accomplishments that we're proud of

An agent that does real work in PayPal, but can't send anything the merchant hasn't allowed.
A full trace behind every action, so the merchant can always see why.
One Pyp across the dashboard, chat, the Chrome extension and Slack.

What we learned

Letting AI decide what to do while code decides whether it's allowed is what makes an agent trustworthy with money.
Structured outputs and idempotency keys matter as much as the prompt.
The PayPal sandbox let us test real invoice and dispute flows safely, without real money.

What's next for Pyp

Let any merchant connect their own PayPal account once Partner Referrals is available.
Pyp-to-Pyp: a buyer's Pyp and a merchant's Pyp negotiating a dispute through PayPal's dispute messages and offers.
Reading more of the account (refunds, subscriptions) and answering any question about your business in chat.

Pyp is an independent hackathon project, not affiliated with or endorsed by PayPal. Sandbox only.