Auto-file emailed vendor invoices as QuickBooks bills

Build an agent workflow that files vendor invoices from Gmail into QuickBooks Online as bills, so accounts payable doesn't have to hand-key them.

Trigger: cron, every 30 minutes.

On each run, the agent should:

1. Use Gmail List Messages to fetch messages that carry a label called 'Bills to file' and do NOT already carry a label called 'Filed to QuickBooks'. If either label doesn't exist yet in the account, create it. Cap the batch at something sensible per run (e.g. 20 messages) so a big backlog doesn't blow up a single execution.

2. For each matching message, look at its attachments. For every PDF attachment, use Gmail Get Attachment to pull it down.

3. Run each PDF through PDF.co's AI Invoice Parser to extract vendor name, vendor contact info if present, line items (description, quantity, unit price, amount), invoice number, invoice date, due date, subtotal, tax, and total.

4. Sanity-check the extraction. If the parser can't confidently produce a vendor + total + at least one line item, OR the document is obviously not an invoice (statement, contract, marketing PDF, receipt with no line items), skip the bill creation, do NOT apply the Filed to QuickBooks label, and use Gmail Reply to a Message to send a short reply to the sender flagging it for manual review. Keep the reply polite and specific about why it wasn't auto-filed.

5. If the extraction looks good, use QuickBooks Query Entities to look up the vendor by name (fuzzy match on DisplayName). If no vendor exists, use Create Vendor to add one with the vendor name and any contact info the parser surfaced. Reuse an existing vendor if there's a clear match.

6. Use QuickBooks Create Bill to post the invoice as an accounts payable bill for that vendor, with the parsed line items mapped to the appropriate expense account (default to a general expense account if the agent isn't sure), the invoice number in DocNumber, the invoice date as TxnDate, and the parsed due date as DueDate. Total should reconcile against the sum of line items.

7. Once the bill is created successfully, use Gmail Modify Message Labels to add a 'Filed to QuickBooks' label to the original email so the same invoice never gets posted twice. Optionally remove the 'Bills to file' label at the same time.

Bias hard toward NOT creating a bill when confidence is shaky. It is much better to reply for manual review than to push bad data into QuickBooks. Never create a bill without a matching or newly-created vendor, and never create a bill for a total the parser is not confident about.

Log what happened per message (posted vs. skipped-for-review vs. errored) so the user can spot-check runs.