Tax Calc

io.github.theluckystrikePublished by GitHub account theluckystrikev1.0.1Updated Oct 30, 2026

US federal income tax estimates: brackets, marginal rate, effective rate. Planning values.

The publisher's own server: calc.engineer

VerifiedSTDIODesktop onlyProductivity & WorkflowFinance

Overview

AI-generated overview

A local MCP server that estimates 2026 US federal income tax for a single filer from gross income, returning total tax, effective rate and marginal bracket.

What you can do
  • Estimate US federal income tax: give gross income and get total tax, effective rate and marginal bracket under 2026 single-filer brackets
  • Apply the standard deduction and walk the 10% to 37% brackets with exact bracket edges
  • Compare income scenarios such as bonuses, side income or two salary levels in one conversation
When to use it
Useful for quick "can I afford X this year" planning chats where you want approximate federal tax figures without handing an email to a web calculator. It covers only single-filer 2026 federal estimates, so it is not a substitute for filing advice or multi-state, multi-status returns.
Requirements
Runs as a local process on the desktop; the README shows an npx command that fetches the package from GitHub, so Node.js and network access are needed for install. No accounts, API keys or environment variables are declared.
Before you install
Figures are approximate planning values, not filing advice, and cover only the 2026 single-filer federal case. The README's install command pulls and runs a package directly from a GitHub repository, so review that source before installing.

Installation

In SourceWeft

  1. Open Tax Calc in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Desktop only via STDIO. STDIO servers start a local process, so they need the SourceWeft desktop host.

Other MCP clients

Follow the launch instructions in the repository.

README

MCP Tax Calculator — 2026 US federal brackets, computed in the conversation

Give Claude (or any MCP client) a tax estimator: us_federal_tax applies the 2026 US federal brackets for a single filer — including the $15,750 standard deduction — and returns total tax, effective rate, and marginal bracket. Planning numbers, computed on your machine, in one sentence.

Why a tax server

Tax estimators on the web want your email before showing a number. This one does the bracket math immediately: give it gross income and get total federal tax, the effective rate, and which marginal bracket your last dollar lands in. Clearly labeled as approximate planning values — not filing advice — but exactly right for "can I afford X this year" conversations.

What it does

  • us_federal_tax — gross income → standard deduction applied ($15,750), 2026 brackets walked correctly (10% through 37%), total tax, effective rate, marginal bracket. Bracket edges are exact, not rounded.
  • A single-tool server that does one thing: ask it as many income scenarios as you like in one conversation — bonus scenarios, side-income scenarios, comparisons.

Install

json
{  "mcpServers": {    "mcp-tax-calc": {      "command": "npx",      "args": ["-y", "github:theluckystrike/mcp-tax-calc"]    }  }}

Try it

  • "Federal tax on 95,000 gross, single filer, 2026 brackets."
  • "Compare tax on 85,000 vs 95,000 — what's the effective marginal hit?"

Part of the luckystrike MCP suite

Free, part of the luckystrike MCP suite — productivity & finance servers that turn AI chat into working documents and calculations. Listing in the official MCP Registry.

Docs (GitMCP)

Live docs endpoint: https://gitmcp.io/theluckystrike/mcp-tax-calc

Source: servers/tax-calc/README.md at commit 1bd9d69

Tools

0
SourceWeft has not started this package in its sandbox yet, so its tools are not known.

Version history

2
  1. v1.0.1LatestOct 9, 2026
  2. v1.0.0Sep 27, 2026

Score

50% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 days25 pts

    Keep the endpoint answering the MCP handshake; SourceWeft probes it every 30 days.

  • Auth declared10 pts

    Declare the credential headers in the registry entry, or keep the endpoint answering the probe so its auth can be classified.

  • Tools listed15 pts

    Answer tools/list without a credential, or ship a package that starts in a sandbox without one.

  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts

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