Hermes skill turns invoices into a ledger CSV with checks

On 2026-10-30 at 18:02, the AI section of DEV Community carried a launch announcement from an author who presented a Hermes skill called invoice-to-ledger-csv. The author framed the problem as the typos that creep in when supplier invoices are typed by hand, citing a digit transposition in the VAT, a date read in the wrong order, and a total that never added up. The skill takes on the mechanical part of the work and, in the author's words, refuses to be overconfident.

In terms of how it runs, the skill reads invoices as text, and it can handle PDFs directly if pdftotext is installed on the system. For each invoice it writes one CSV row, with fields covering supplier, invoice number, date, currency, net, VAT, VAT rate, gross, a suggested category, and a status field. The central piece is the checking logic: it verifies that the net amount plus the VAT equals the gross total, and that the VAT rate is consistent with what was parsed. Rows that fail these checks get marked with the status REVIEW and are returned together with an error code. Labels are supported in both English and French, and common number formats are handled.

The author also flagged the limits: invoices carrying multiple VAT rates, as well as invoices with unusual layouts, will be misjudged by the skill. No follow-up coverage has appeared since the announcement, so the story currently stands at this single release post.