Healthcare · optometry · HIPAA · Wichita Family Vision · Live 2026-10-01

Invoice processing for a clinic's bookkeeper: she never processes an invoice by hand again.

The bookkeeper used to key every vendor bill into QuickBooks and file every PDF by hand. Now she checks one table and clicks Go: each invoice is read, filed in the right vendor folder and entered in QuickBooks, following the clinic's vendor rules every time.

~200hrs/yr of keying and filing off the bookkeeper's desk, at the 50 invoices a week the clinic plans for as it expands 50 invoices a week, the volume the clinic plans for as it expands its services, at about 5 minutes each to key the bill into QuickBooks, rename the PDF and file it, over 50 working weeks: about 4 hours a week, about 200 hours a year.

0failures on every real invoice she has run since go-live, and not one Undo. In our side-by-side test, QuickBooks' own reader got 40% of totals wrong

One run: the bills are read and checked, the ready ones go into QuickBooks, and the one that doesn't add up waits for her. Sample vendors and amounts, screens simplified.

The review table with eight invented invoices: new file names, vendor folders, dates, amounts, QuickBooks vendor and account dropdowns, and a note per row, including a Select Optical order going in as a card expense — The one table she checks. Invented invoices; nothing moves until Go.

At a glance

Client: Wichita Family Vision, an independent optometry practice in Wichita, Kansas.
Who uses it: The clinic's bookkeeper, since the install on 2026-10-01.
Shipped: Live 2026-10-01. About 5 weeks from first scoping to install, including a rebuild onto the QuickBooks API.
Stack: Claude on AWS Bedrock
Python
QuickBooks Online Accounting API
OAuth 2.0
PyMuPDF
PyInstaller
Amazon S3
CloudWatch
Ed25519 signed updates
Windows
Compliance: HIPAA compliant by design. Pages are read by Claude on AWS Bedrock inside the clinic's own AWS account, under the clinic's business associate agreement with AWS. Invoices that name a patient go through that same protected path as every other page. QuickBooks only ever receives the vendor, date, invoice number and amount, never the page, and error reports leave out every file name and anything read off a page.
Cost to run: About 1 cent an invoice in the clinic's AWS account, measured from its Bedrock usage: a few dollars a month at 50 invoices a week.
My role: I built it: the app, the QuickBooks integration, the self-update system and the tests. My co-founder worked the QuickBooks setup with me and joined the install.

What was broken

Before

Every vendor bill arrived as a PDF or a scan. The bookkeeper read each one, typed it into QuickBooks and filed it by hand into one of 184 vendor folders, keeping a set of rules in her head: frame vendors go in by their monthly statement, some lab vendors invoice by invoice, card-paid orders as expenses. The clinic plans for 50 invoices a week as it expands its services, and the owner wanted none of it to depend on one person. Some pages name patients, so ordinary AI tools without a HIPAA agreement were ruled out from the start.

What I built

The build

One review table. Every PDF in the Invoices folder is read and shown on a single page: the new file name, the vendor folder, the date, the amount, the QuickBooks vendor and the expense account, prefilled from how she has coded that vendor over the last 12 months. She fixes anything in place and clicks Go.
Her rules, in code. Frame vendors go in by statement and their invoices are filed only; lab vendors go in invoice by invoice; card-paid vendors go in as card expenses on the right card, dated the order date. Anything that might already be in QuickBooks is shown to her instead of entered twice, and every run can be undone.
Straight into QuickBooks through its API. Bills and card expenses are created from our own read, so QuickBooks never re-reads a page. A bill that cannot go in yet waits safely and goes in with one click once she fixes the reason.
Kept fast as she used it. After her first weeks, launch went from about 2,100 files unpacked to 181, reading runs three invoices at a time, and the bill memo now says what the bill was for.
Built to be looked after from a distance. Fixes arrive as signed updates that install when she closes the app, and an error report reaches us the moment something goes wrong. When she tells us a vendor rule changed, the next update edits her Filing Rules file and keeps a copy of the old one.

The result page: five entries in QuickBooks, including a card expense, two documents filed but not entered, one file left for her — After Go: what went into QuickBooks, what was filed only, what still needs her.

A result page with one bill waiting because the vendor is not in QuickBooks yet — A bill that can't go in yet waits, and goes in with one click once she adds the vendor.

What changed

Before and after

Before

By hand

Entering a billTyped by hand from the PDF

Filing the PDFRenamed and dragged into 1 of 184 folders

Vendor rulesIn one person's head

Totals right in a 5-invoice test3 with QuickBooks' own reader

Since go-liveEvery bill keyed by hand

After

The system

Entering a billRead, checked in one table, entered on Go

Filing the PDFRenamed and filed on the same click

Vendor rulesWritten once, followed every run

Totals right in a 5-invoice testAll 5

Since go-live0 failures, not one Undo

Where the numbers come from. The hours figure is a planning estimate, not a measurement: 50 invoices a week (the volume the clinic plans for as it expands) at about 5 minutes each to key, rename and file by hand, over 50 working weeks. She still checks the table, and the app puts an odd one to her rather than guessing (a possible duplicate, a zero-dollar rewards order). Running cost measured in the clinic's AWS account: about 1 cent an invoice.

For engineers

How it's built

Architecture: A one-file Windows app that serves its own page on 127.0.0.1. The model only reads: each PDF goes to Claude Sonnet 4.6 on Bedrock. Everything after the read is deterministic code: vendor matching against her folders and her Filing Rules, which documents become bills, card expenses or nothing, the usual account from 12 months of her QuickBooks history, duplicate checks on vendor, number, date and amount, then bills or card expenses through the QuickBooks Online Accounting API with idempotent requests.
Where it runs: On the bookkeeper's PC against the clinic's network drive. Reading runs in the clinic's own AWS account (us-east-1) under its BAA; QuickBooks is reached through OAuth, authorized by a company admin; signed updates come from the clinic's S3 bucket, and error reports go to its CloudWatch.
Tests and evals: 40 offline cases against a fake QuickBooks; 25 browser checks on the real page; 22 update and reporting tests; every Windows build swaps itself between two real builds in CI. Before the install, a full code review found 39 verified issues; all were fixed and the fixes reviewed again.
Cost and latency: About 1 cent an invoice in the clinic's AWS account, measured from its Bedrock usage: a few dollars a month at 50 invoices a week.
Guardrails: Nothing moves until she clicks Go. Undo moves the files back first, then removes only those bills, never a paid one. A possible duplicate is put to her, never entered or skipped silently. Updates are signed and only swap in when she closes the app, so a running session is never disturbed. Testing runs on invented invoices on our own account, never on the clinic's.
The tradeoff we chose: Why this way and not the other
QuickBooks can read bills itself, and version 2 used that: on her real invoices it got 2 of 5 totals wrong, reading a discount as a charge and a unit price as the total. Version 3 keeps the reading in our model and writes the entry through the API with her rules in code. Claude Team and Cowork were the easier surface, but neither carries a BAA, so the reader moved to Bedrock in the clinic's own account.

In their words

“I think that's very simple and effective… I don't have to enter [them]. I just have to go back in and pay [them] when it's an appropriate time to pay [them].”

Mary Tangney, Bookkeeper, Wichita Family Vision