Demo: Invoice Folder Watcher → Weekly Summary Email Draft

Demonstration project. The invoice files in invoices/ are synthetic. This is a small, complete example of the "boring automation" tier of our work: a script that removes a recurring 30-minute manual chore.

The chore it replaces

Every Monday someone opens last week's invoice exports, adds up what went out, checks what got paid, hunts for overdue invoices, and writes a status email. It takes half an hour, it's error-prone, and it silently stops happening when that person is busy — which is exactly when receivables slip.

What the automation does

invoice_watcher.py watches a drop folder where the accounting tool (or a bookkeeper) exports invoice CSVs.

• Ingests only new/changed files (state in .seen_files.json — nothing double-counted; a re-exported file with corrections simply supersedes the old rows by invoice number)
• Tolerates real-world mess: mixed date formats, $1,234.56 amounts, extra columns
• Every Monday (or on demand) writes a ready-to-send email draft: invoices issued and week-over-week movement, payments recorded, total outstanding, and a named, dated overdue follow-up list
• Runs anywhere Python runs; --watch mode polls the folder, --once suits a scheduled task (cron / Task Scheduler)

See the real output of this demo run: outbox/weekly_summary_2026-07-13.md — note it flagged INV-3107 (fictional Lakeshore Legal Group), $3,150 at 22 days past due. Drafts are marked for human review before sending; we can wire actual delivery (Gmail/Outlook/Slack) in a client engagement.

Why it's in the portfolio

Dashboards answer questions; automations delete chores. Most clients who buy a dashboard have three of these chores lying around. They're small fixed-scope builds (typically bundled into our Reporting System package or a Data Care plan), and this one is fully runnable so you can judge the code quality:

python3 invoice_watcher.py --once --as-of 2026-07-20

Files

• invoice_watcher.py — the automation (commented, auditable)
• invoices/*.csv — three synthetic weekly exports, defects included
• outbox/weekly_summary_2026-07-13.md — the generated draft
• .seen_files.json — ingestion state (created on first run)

Built by Modular Enrichment. AI-assisted delivery, human-QA'd — openly.