Crypto invoicing for freelancers on Telegram
A Mini App that accepts payment in TON and USDT and automatically issues the client a signed invoice with real business details.
The task
Freelancers and small businesses in the CIS region struggled to accept crypto payments from foreign clients: there was no single payment link, payments had to be confirmed manually via a block explorer, and tax reporting needed legally valid documents — with different requirements across five countries.
The solution
We built a Telegram Mini App in Go with its own TON client (direct connection to liteservers, no third-party APIs) and a TronGrid integration to accept TON and USDT across two networks. A background monitor tracks payments on-chain and converts the amount to local currency at the central bank rate, and right after payment confirmation it generates and sends a PDF package to Telegram: a certificate of completed work and, for Russia, a VAT invoice.
The result
- Payments are confirmed automatically, with no manual explorer reconciliation
- The certificate and invoice reach the client immediately after payment, in the recipient country's language
- Multi-currency invoices accept payment on any of 3 networks at the rate fixed at creation
- Fully self-driven CI/CD — moving to a new server takes a single push to main