The ledger asks the model to show its work before it counts the money

A donation ledger has been created to help small groups, such as neighborhood funds and school parent groups, manage their finances more efficiently. This ledger is built using a Google Sheet, some Apps Script, and Gemini, and it allows donors to view a public page where their contributions are recorded and tracked.

The ledger started off as a simple solution to the problem that arises when donors inquire about the whereabouts of their contributions months later. Traditional software solutions are either too expensive for small groups or require a dedicated finance team to manage them. So, the ledger was built using a familiar tool for volunteers - Google Sheets - with an added layer of verification using Gemini's artificial intelligence.

Gemini reads donation messages and verifies the extracted amount from the message against the amount recorded in the Google Sheet. If there is a discrepancy or if the model is unable to extract a valid amount, the entry is flagged as "needs-review" instead of being automatically added to the ledger. This ensures that any potential errors are caught and can be manually reviewed by a volunteer before the donation is recorded.

The public page that donors can access displays the verification process, highlighting the exact characters Gemini read from the donation message and listing the check results. This transparency helps build trust in the ledger's accuracy and encourages donors to participate confidently. The ledger not only solves the immediate problem of donors asking where their money went, but also adds an extra layer of accountability and trust for small charity groups.