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MCP Tax Calculator in VS Code

2026 US federal brackets, computed in the conversation. us_federal_tax applies the 2026 US federal brackets for a single filer — marginal rates by band with the standard deduction applied first — and returns tax owed plus the effective rate; it is a planning estimate computed exactly, not a filing tool, and the bracket table it uses is in the source where you can read it.

One pure tool, no writes, no network: auto-approve in agent mode so tax math inside a compensation-planning task costs no clicks.

What you get in VS Code

The contract suite walks real stdio cases through the bracket table: 95,000 gross less the 15,750 standard deduction is taxed band by band with the marginal rate applied only above each threshold, the returned effective rate equals tax divided by gross, and a below-deduction income returns zero.

Install it in VS Code

The file is .vscode/mcp.json, and the key inside it is servers.

If you also run Claude Desktop, the shortest path there is one click: tax-calc.mcpb from the latest release opens as an extension, with no JSON and no terminal. VS Code reads its own config, so here it is:

// .vscode/mcp.json  (the key is "servers")
{
  "servers": {
    "tax-calc": {
      "command": "node",
      "args": ["/absolute/path/to/mcp-servers/servers/tax-calc/dist/index.js"]
    }
  }
}

Or from a terminal:

code --add-mcp '{"name":"tax-calc","command":"node","args":["/absolute/path/to/mcp-servers/servers/tax-calc/dist/index.js"]}'

The node command above wants a built file. From a clone, once:

git clone https://github.com/theluckystrike/mcp-servers.git
cd mcp-servers && npm install
npm run build -w packages/mcp-license -w servers/tax-calc

That writes servers/tax-calc/dist/index.js, and its absolute path is the one argument the config needs.

The npm packages are not published yet, so the form below returns a 404 today. It is here because it is what the entry becomes the day the publish lands, with nothing else changed:

code --add-mcp '{"name":"tax-calc","command":"npx","args":["-y","@theluckystrike/mcp-tax-calc"]}'

VS Code asks you to confirm you trust the server and its capabilities before it starts. Nothing runs until you answer.

Nothing is published to npm yet, so the working install paths are the ones above: the .mcpb bundle from the latest release, a clone and build, or the hosted URL.

No install: the hosted endpoint

There is no hosted endpoint for this one yet. MCP Tax Calculator runs locally over stdio with the config above, which is also the only form in which it reads and writes files on your own disk. Thirty of the servers in this collection are served at https://mcp.zovo.one/mcp/<name> over MCP streamable HTTP; https://mcp.zovo.one/mcp/connect lists them and prints a ready URL for each.

VS Code notes worth knowing first

The top-level key is "servers", not "mcpServers". A config pasted from a Claude Desktop or Cursor README parses cleanly, contributes no servers, and gives you no error to read, which makes it the most expensive one-word mistake here. Alongside it an "inputs" array holds secrets. The newer Agent Host reads a workspace .mcp.json instead.

Free: Everything: one tool, no metering, no key. Pro is $19 once, verified offline.

Questions

Why does my mcp.json do nothing?

The key is servers, not mcpServers. A config copied from a Claude Desktop README parses cleanly and contributes nothing. Rename it. On the newer Agent Host, use a workspace .mcp.json instead.

Do I have to edit the file at all?

No. code --add-mcp takes the server object on the command line, and MCP: Add Server in the palette asks whether the target is Workspace or Global.

Where do the MCP Tax Calculator tools show up?

In Chat, behind the tools picker, once the server has started. Adding or changing one raises a prompt asking you to confirm you trust it; if the picker is empty, that prompt is usually still waiting.

Related

MCP Tax Calculator in detail · The same server in Cursor and Windsurf · Every server in VS Code · Guides · VS Code docs · Buy Pro