SelfTax
What SelfTax is
SelfTax is a free tax-preparation project that reads tax documents, calculates a federal return, and fills supported free IRS filing sites. It is aimed at people who want to avoid paying for tax preparation or spending hours filing. Tax calculations use deterministic code, and the README says each line can be audited. Structured IRS forms are processed locally. When unstructured documents need AI interpretation, identifying details are replaced with tokens locally before the text is sent. Names, addresses, and Social Security numbers are stored in browser local storage and are not transmitted, according to the README.
Verified coverage for tax year 2025 includes W-2 wages, rental income with passive activity loss, capital loss carryover, itemized deductions, child tax credit, dependent care credit, and the QBI deduction. Schedule C, K-1, education credits, EITC, AMT, and self-employment tax are described as built but not fully tested. Users build and load SelfTax as a Chrome extension. An optional local HTTP server uses the Claude Code CLI to parse redacted documents, with the user’s Anthropic API key managed by that CLI. SelfTax can also run as an MCP server for Claude Code, with tools for tax-folder scanning, profile setup, document review, calculations, and form generation. The project uses the AGPL-3.0 license, which requires products or services built from the code to open-source their versions under the same license.
Who it suits
SelfTax may suit individuals preparing a federal return who want document-based calculations and support for listed free IRS filing sites. It is also relevant to people comfortable building a Chrome extension or using Claude Code for optional document parsing and MCP workflows.
What it does well
- Free federal tax preparation project.
- Calculations use deterministic code with auditable lines.
- Processes structured IRS forms locally.
- Redacts identifying details before AI interpretation.
- Supports several verified tax-year 2025 items.
What to know first
- Coverage for several listed tax features is not fully tested.
- The browser extension must be built and loaded.
- AGPL-3.0 requires derived products or services to open-source their version.
Limits
SelfTax supports federal returns and its verified tax-year 2025 coverage includes the listed supported income and deduction items. Schedule C, K-1, education credits, EITC, AMT, and self-employment tax are built but not fully tested.
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| Free | Free AI-powered tax preparation · federal return · supported free IRS filing sites | Free |
As github.com lists them, read 8 Oct 2026. The maker's own page has the final word.
Getting started
- Visit https://github.com/selftax/selftax.
- Build and load SelfTax as a Chrome extension.
- Use it to read tax documents and calculate a federal return.
- Use the optional local HTTP server with Claude Code CLI for redacted document parsing.
- Alternatively, run SelfTax as an MCP server for Claude Code.
Verdict
Consider SelfTax if its verified tax-year 2025 coverage fits your situation and you are comfortable building and loading a Chrome extension. Look elsewhere if you need assurance for Schedule C, K-1, education credits, EITC, AMT, or self-employment tax, which are built but not fully tested.
Questions
Does SelfTax cost anything?
SelfTax is free. Its plan is listed as free.
What kind of return does it support?
The listed filing support is for federal returns and supported free IRS filing sites.
Which tax items are verified?
For tax year 2025, verified support includes W-2 wages, rental income with passive activity loss, capital loss carryover, itemized deductions, child tax credit, dependent care credit, and QBI deduction.
Is SelfTax open source?
Yes. It is licensed under AGPL-3.0, which requires products or services built using the code to open-source their version under the same license.
How does its optional AI parsing work?
An optional local HTTP server uses the Claude Code CLI to parse redacted documents. The user’s Anthropic API key is managed by that CLI.
Where are names and Social Security numbers stored?
The README says names, addresses, and Social Security numbers are stored in browser local storage and never transmitted.
Facts from SelfTax's own pages
- Browser extension
- The README instructs users to build and load SelfTax as a Chrome extension. · github.com, 8 Oct 2026
- Document parsing
- Structured IRS forms are processed locally; AI is used only to parse unstructured documents when needed. · github.com, 8 Oct 2026
- Intended user
- The maker describes the project as built for people who want to avoid paying for tax preparation or spending hours filing their taxes. · github.com, 8 Oct 2026
- Local server
- An optional local HTTP server uses the Claude Code CLI to parse redacted documents, and the user’s Anthropic API key is managed by that CLI. · github.com, 8 Oct 2026
- MCP integration
- SelfTax can run as an MCP server for Claude Code and exposes tools to scan tax folders, set a profile, view documents, calculate taxes, and generate forms. · github.com, 8 Oct 2026
- Open-source license
- SelfTax is licensed under AGPL-3.0, which the README says requires products or services built using the code to open-source their version under the same license. · github.com, 8 Oct 2026
- Privacy
- The README says SSNs, names, and addresses are stored in browser local storage and never transmitted. · github.com, 8 Oct 2026
- Purpose
- SelfTax reads tax documents, calculates a federal return, and auto-fills supported free IRS filing sites. · github.com, 8 Oct 2026
- Redaction
- Before unstructured document text is sent for AI interpretation, the README says identifying details are replaced with tokens locally. · github.com, 8 Oct 2026
- Supported filing
- Tested and verified support includes W-2 wages, rental income with passive activity loss, capital loss carryover, itemized deductions, child tax credit, dependent care credit, and QBI deduction for tax year 2025. · github.com, 8 Oct 2026
- Tax calculations
- Tax calculations use deterministic code, and the README says each line can be audited. · github.com, 8 Oct 2026
- Unverified coverage
- The README lists several features as built but not fully tested, including Schedule C, K-1, education credits, EITC, AMT, and self-employment tax. · github.com, 8 Oct 2026
Where SelfTax stands on Freedom251
- AI Tax Software#12 of 32