MCP serverio.github.Invaro/opentax

Compute US federal BUSINESS-ENTITY tax from the same cited corpus: check-the-box entity classification, Form 1120 corporate income tax (§ 179/168(k)/174A/163(j)/DRD/NOL, § 250, GBC

Compute US federal income tax for an ESTATE or TRUST (Form 1041): the § 1(e) compressed brackets and § 642(b) exemption. Input is taxable income before the exemption, after the §§

Compute US federal INDIVIDUAL income tax (or balance due if withholding is given) from a content-addressed corpus of cited rules. NEVER estimate tax yourself — call this, and repor

Compute the answer under every filing status for the same facts — e.g. to answer 'should we file jointly or separately?'. Statuses that need more facts report their error instead o

Compute the COMPLETE Form 1040 bottom-line set in one call — the 17 lines that determine the return (1a, 9, 10, 11, 12e, 15, 16, 17 AMT, 19, 22, 23, 24, 25d, 27a, 28, 32, 33, 34/37

Compose a STATE return's printed-form line set deterministically (2025 IL-1040 / VA 760 / CA 540 / NY IT-201 / PA-40 / NJ-1040 / OH IT 1040 / NC D-400 / GA 500 / MD 502 / MO-1040 /

Determine whether ONE candidate person is the taxpayer's § 152 dependent — qualifying child or qualifying relative, including multiple-support agreements and the divorced-parents r

Get a tax rule's statutory citation, verbatim excerpt, validity window, parameters, and dependencies. Use to quote the actual law behind an answer.

Find exact dollar amounts where one more cent of an input costs MORE than a cent of tax (marginal rate over 100%) — e.g. the EITC investment-income kill switch, CTC phase-out steps

Determine whether a job is on the Treasury Tipped Occupation list (Treas. Reg. § 1.224-1, final Apr 2026) for the § 224 'no tax on tips' deduction. Fuzzy-matches the job name; retu

Discover every input the tax corpus understands: id, type, whether required, and its documented default. Call this if unsure what information to collect from the user.

Look up the current-law dollar amounts behind a question ('standard deduction', 'CTC phase-out threshold', 'tips deduction cap') with their statutory citations and validity windows

Full-text search over the encoded tax-law corpus ('kiddie tax', 'NIIT threshold', 'california renters credit'). Returns matching rules: id, title, statutory citation, effective win

Fact-check a claimed dollar amount about tax law ('the 2026 MFJ standard deduction is $32,200', 'CTC is $2,000 per child') against the corpus. Returns verified / refuted (with the

Verify a claimed tax amount (yours, a user's, or another tool's) against the law. Returns verdict 'verified' or 'refuted' with the correct value. Use this as a self-check before pr