What they do and how
The first flow detects new invoices in Google Drive, extracts their data with PDF.co and ChatGPT, normalizes the information, renames and classifies the files by year, quarter and type, removes duplicates and updates a Google Sheets spreadsheet prepared for import into ALTAI. The second, a “secretary agent”, receives appointment requests by WhatsApp as text or audio, interprets them with ChatGPT and Whisper, checks Google Calendar and schedules or changes the appointment, with automatic confirmations to the client. The work also covers access control in Drive, n8n logs and data retention in line with the GDPR and Spain’s LOPDGDD.
Reported result
Stated by the author: processing time per invoice drops from 2 minutes to about 30 seconds (75% less) with fewer transcription errors; the secretary agent handles about 140 meetings and 50 inquiries a month with no manual intervention; and manual processing costs fall by more than 80%. The abstract also says the firm could take on more clients without expanding its staff.
Stated figures. An identified person or organization states that they have used it. The results are stated by the source; we have not audited them.
What has really been tested
It is an academic work on a real firm, with implementation at the advisory firm itself according to its abstract. We have read only the repository record, not the full 11 MB PDF, so we could not check how the figures were measured or how many months of use are behind them. We have not reproduced the flows.
How to replicate it
Start from an invoice folder with a fixed structure (year, quarter, type). In n8n, build a flow that triggers when a new file arrives, extracts the text, asks a model for the invoice fields in a fixed format and writes a row to a sheet with the columns your accounting program expects. Check for duplicates before writing, keep logs of each run and review a sample by hand during the first weeks. Restrict access to the folder and validate the processing of client data with your data-protection advisor.
Important nuances
- The repository abstract talks about “agents”, but in practice they are automation flows in n8n that call a model to read documents and understand messages.
- The license given in the repository is Creative Commons Attribution-NonCommercial. This entry summarizes the content in our own words and links to the original.
- Invoices contain third parties’ personal data: before replicating this, review with whom the data is shared when using external extraction and AI services.
Sources
We wrote this entry in our own words from the sources above and checked that the links worked on October 17, 2026. Is anything incorrect? Tell us.
