Open source · Local-first · v0.1

The AI that manages your money

It categorizes your spending, tracks subscriptions, prepares your taxes, and watches your portfolio. Everything runs locally on your machine.

Nullbook
New Chat
Today
2025 tax estimate
RSU vesting tax impact
Previous
Audit SaaS subscriptions
Home office deductions
January spending review
Accounts
Portfolio
Taxes
Subscriptions
Email
Alerts
News
Import
Settings
You
Estimate my taxes for 2025
Nullbook
Calculating tax estimate...
2025 Federal Tax Estimate
Single
Estimated Refund
+$1,853.00
Income
Gross Income$185,000.00
AGI$185,000.00
Taxable Income$170,000.00
Deductions
Standard Deduction$15,000.00 ✓
Itemized Deductions$12,840.00
Tax Brackets
10%12%22%24%
Tax Breakdown
Ordinary Income Tax$33,647.00
Total Federal Tax$33,647.00
Total Withheld-$35,500.00
Effective Rate: 18.2% Marginal Rate: 24%
This is an estimate only. Consult a tax professional for official filing.

You're looking at a $1,853 refund for 2025. The standard deduction of $15,000 saves you more than itemizing ($12,840). Most of your income falls in the 22% and 24% brackets.

Ask anything about your finances...
What it does
Your entire financial life,
managed by AI
Most finance apps show you charts. Nullbook actually does the work: categorizing transactions, finding waste, and keeping your numbers organized.

Spending Intelligence

Every transaction gets categorized automatically. You'll see exactly where your money goes, including patterns you might not notice on your own.

Subscription Tracking

Finds every recurring charge across your accounts. If a service raises its price or you stop using it, you'll know right away.

Tax Preparation

Pulls deductions straight from your transactions. Estimates your taxes for any filing status, and generates Schedule C if you're self-employed.

Portfolio Monitoring

Keep tabs on your holdings with unrealized gain/loss calculations and allocation breakdowns. Prices update daily.

Receipt Processing

Drop a receipt into the chat and it gets read automatically. Merchant, amount, and line items are extracted and matched to your transactions.

Email Scanning

Connect your Gmail or any IMAP inbox. Nullbook picks up purchase confirmations, receipts, and bills on its own.

Smart Alerts

Get a heads-up on unusual charges, upcoming bills, low balances, and new fees before they become problems.

Data Import

Bring in CSV, OFX, or QIF files from any bank, or connect Plaid for automatic sync. Works with whatever export your bank gives you.

See it in action
Intelligent, not just informational
Ask a question in plain English and get a real answer with your actual numbers. Not a chart you have to interpret yourself.
Nullbook
New Chat
Today
401k allocation check
February spending
Previous
Audit SaaS subscriptions
Import Schwab CSV
Home office deductions
Accounts
Portfolio
Subscriptions
Settings
You
Where did my money go last month?
Nullbook

You spent $4,518 in January. Here's the breakdown:

Spending by Category
Housing$2,800.00
Food & Dining$847.00
Transportation$312.00
Software & SaaS$214.00
Utilities$189.00
Shopping$156.00
Total$4,518.00

DoorDash and Uber Eats were $384 of that, up 42% from December. Also, you haven't used Figma in 2 months but you're still paying $15/mo. Want me to draft a cancellation email?

Ask anything about your finances...
Your data stays yours
Runs on your machine.
Not ours.

Nullbook runs entirely on your computer. Your financial data lives in a local SQLite database. The only external call is to Claude for AI analysis, and even that's optional.

0
Cloud servers
SQLite
Local database
MIT
Open source license
100%
Self-hosted
Get started
One command to install
curl -fsSL https://nullbook.ai/install.sh | bash
or npx nullbook · or git clone and make setup
Requires Python 3.11+, Node 18+. macOS and Linux.
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