Inspiration
A chit fund is a rotating savings circle: ten friends each put in a fixed amount every month, and each month one member takes the whole pot. Hundreds of millions of people in India, Africa, Latin America and immigrant communities save this way. It runs on trust, a notebook and WhatsApp reminders, and it breaks when someone forgets to pay, the organiser moves away, or the money has to be collected in cash. Fintech has mostly ignored it. We thought an AI agent plus PayPal's invoicing and payout rails could make this ancient, trusted instrument safe and effortless.
What it does
The organiser describes the circle in plain language: "10 of us, 5,000 rupees a month, starting December, winner picked by lottery." ChitCircle's agent:
- Creates every member as a PayPal invoice recipient and sets up a recurring invoice series for the circle's lifetime.
- Each cycle, sends the invoices, watches payments land, and records payments against each invoice.
- Nudges late members with escalating, friendly reminders (PayPal invoice reminders plus a written note from the agent that knows each member's history).
- When the pot is full, runs the draw (lottery or auction, the two classic chit formats), and pays the winner through PayPal Payouts.
- Keeps a transparent ledger every member can see: who paid, who won, what is due, all backed by PayPal transaction IDs.
- Answers questions in chat: "what do I still owe?", "when is my turn?", "what happens if Ravi drops out?" (it explains the rules and simulates the outcome).
The organiser's dashboard uses AG Grid for the member ledger and cycle history.
How we built it
- Next.js 15 + TypeScript on Vercel.
- PayPal Invoicing v2 via the PayPal Agent Toolkit (create_invoice, send_invoice, send_invoice_reminder, record_payment_for_invoice, create_recurring_series, list_invoices, search_invoicing).
- PayPal Payouts API for the monthly disbursement to the winner.
- PayPal Transaction Search for the reconciled ledger.
- Claude (Anthropic API) parses the organiser's description into a validated circle contract (members, amount, cadence, draw rules), writes the member-facing reminders, and runs the chat assistant with the Agent Toolkit as its tools. All money movements are deterministic code with the model only allowed to propose, never to pay.
- AG Grid for the ledger and cycle grids.
Challenges we ran into
Modelling chit rules faithfully (lottery vs auction, foreman commission, dropouts) so the agent explains them correctly. Keeping the agent out of the money path: it drafts, code validates and executes, PayPal records. Simulating a multi-month cycle convincingly in a 3-minute demo.
Accomplishments that we're proud of
A savings instrument used by hundreds of millions of people gets a transparent, automated, PayPal-backed version that a non-technical organiser can set up by describing it in a sentence.
What we learned
PayPal's recurring invoice series plus Payouts is a complete substitute for the notebook-and-cash chit. Agentic UX is at its best when the agent handles the social part (reminders, explanations) and code handles the money.
What's next
Member-side mobile view, auction-format bidding through the chat, multi-currency circles for diaspora groups, and a default-protection pool funded by the foreman commission.
Built With
- ag-grid
- anthropic
- nextjs
- paypal
- react
- tailwindcss
- typescript
- vercel
