InvoiceGen — batch invoicing

One spreadsheet of line items becomes a folder of finished invoices, plus an index that totals them.

Real Word invoices: header, bill-to, line-item table, subtotal / tax / total, payment details
Chinese 大写金额 done right (叁万零壹佰肆拾肆元整, not 叁万壹佰肆拾肆), or blank for non-CNY
Auto invoice numbers grouped by customer + month, never colliding with your own numbers
Money carried as integer cents, so totals never drift by a cent; optional printable HTML

29 USDT

Pay in USDT (BEP20). The download link unlocks the moment the transfer confirms — no account needed.

What you get

A single Python file plus a one-page README — no framework, no account, no license server.
Sample data and a runnable demo, so you can see the output before you read the code.
Source included. Runs offline on Python 3.9+. Most tools use the standard library only.

unzip invoicegen.zip && cd invoicegen
pip install -r requirements.txt   # only if the README lists one
python invoicegen.py demo/input.csv -o out.csv

One-time payment, no subscription, no seat count. If the file will not run on your machine, reply to the order and it gets fixed or refunded.