U.S. tax return App

Snap your tax documents. Get your federal return. Read every line of the code behind it.

• ~86,700 lines of tax calculation
• ~31,500 lines of input validation
• 254,600 lines of code, written by AI

• 139 different full screens, including each document editor
• 5,951 fields a filer can see
• 9,501 fields in the public schema

Read the metrics

Every figure explains itself

Every line the App calculates comes with its explanation: how the amount was worked out, the IRS form, instructions or publication it follows, and the entries and earlier lines it came from.

When the App can't calculate something, it doesn't guess. Each gap is its own note on the Review page. The note says what is out of reach and links to the page where you enter the missing fact. Nothing silently counts as zero.

Document center: your paperwork is the interview

Most tax software makes you retype your forms. Here you start with the documents themselves. Photograph or upload your W-2s, 1099s, K-1s and other statements, and AI reads each one into the matching entries. You check the result and save it; nothing is accepted without you. Each document stays listed under whose it is, and every figure on the return traces back to it.

The interview then asks only about what your documents cannot say: your household, your dependents and your situation.

Written by AI. Open line by line.

All of it is public on GitHub. Every rule, limit and calculation is source code you can read, with the IRS form or publication it comes from.

Coverage: TurboTax-level, and closing fast

The goal is the coverage of TurboTax. Changes land every day.

• Federal, today. Form 1040 with its schedules, worksheets and credit forms: wages, business, farm, rental, investments, retirement, foreign income, education, health coverage, and much more. The coverage audit lists every form and its limits.
• State, next. State and local tax is not calculated yet. The state boxes on your W-2s and 1099s are already kept for it.

It is a 2026 estimate on the IRS draft forms and tables, with synthetic data. It does not print or file a return.

Try it

Use your phone or tablet for the full experience. AI features, including the document center's reading of your documents and AI Search, are turned off on the web. On the web you enter documents by hand.