Inspiration
Small shops everywhere sell on credit and write it in a paper notebook (a "khata"). Notebooks get lost, only the shop can see them, and when a customer says "I already paid", nobody can prove it. We wanted a credit book that both sides can trust.
What it does
Khataz is a shared credit book for small businesses. It records money; it never moves it.
- Shared records: the shop and the customer see the same account. A wrong entry can be cancelled within 24 hours; after that it's final.
- AI entries: type one normal sentence ("Rosie's Bakery took 20 litres of milk for 30 dollars") and AI picks out the customer, item and amount. Nothing is saved until you confirm.
- AI assistant with voice: speak or type; AI turns speech into text, then adds, updates, undoes or shows records.
- PayPal proof: customers connect with Log in with PayPal, so the sender is verified. Khataz checks the shop's own PayPal with the Transaction Search API. If someone claims $10 but only $8 arrived, only $8 is counted.
- All records in one AG Grid table, smart search with Elastic, plus chat and notifications.
How we built it
FastAPI, PostgreSQL and React. PayPal through APIMatic's PayPal Server SDK and Log in with PayPal (sandbox). AI through Groq (gpt-oss-120b) and Whisper for speech. AG Grid for the records grid, Elasticsearch for search.
Challenges we faced
PayPal isn't fully available in Pakistan, so we built and tested everything on the PayPal sandbox. Payers sometimes claim more than they sent, so we made PayPal's amount the only one that counts. Getting Log in with PayPal working took careful setup of return URLs and account types.
What we learned
How PayPal's login and reporting APIs fit together, and how to keep AI safe by letting it propose an entry while the person confirms it.
What's next
Urdu and other languages, payment links so customers can pay straight from Khataz, and reminders for overdue balances.
Built With
- ag-grid
- apimatic
- docker
- elasticsearch
- fastapi
- groq
- log-in-with-paypal
- paypal
- paypal-transaction-search
- postgresql
- python
- react
- sqlalchemy
- vite
- whisper
