Kultranz MCP Server — US Salary, Tax & Cost of Living

Remote MCP server (Streamable HTTP) + REST API over real US government data. Live endpoint: https://api.kultranz.com/mcp — no auth, no API key. The free tier is metered: 200 tool calls/day per IP (initialize, ping and tools/list are never metered; JSON-RPC batches are capped at 16 entries).

Five read-only tools a model cannot compute itself:

Why this exists

Ask five paycheck calculators what $85,000 nets in Missouri and you will get five answers, because three 2026 state schedules are widely mis-modeled: Missouri is graduated (0 to 4.7% starting above $9,436, not flat), Mississippi charges 0% on the first $10,000, and Ohio taxes nothing below $26,050. All three were corrected on 2026-10-09 against the state Departments of Revenue, and everything behind the fix is open: the datasets (CC BY 4.0), the D1 seed, and this server.

The bar this repo holds itself to: if a number cannot be traced to a named release (BLS OEWS, BEA RPP, Census ACS, IRS Rev. Proc. 2025-32, or a state DOR form), it does not ship. Corrections are applied fast: open an issue with the source and we fix the data, not the marketing.

Related MCP server: publicfinance

Use it

Any MCP client that speaks Streamable HTTP (Claude Desktop, Claude Code, Cursor, Windsurf):

claude mcp add --transport http kultranz https://api.kultranz.com/mcp

Or in a client's JSON config:

{
  "mcpServers": {
    "kultranz": { "url": "https://api.kultranz.com/mcp" }
  }
}

Stateless server: plain POST https://api.kultranz.com/mcp with JSON-RPC 2.0 works from curl or fetch, no session required.

Pricing

Docs and full pricing: https://kultranz.com/pages/api-docs/?utm_source=github&utm_medium=organic&utm_campaign=revtest-oct

What is in this repo

A complete, deployable Cloudflare Worker: the MCP server, the REST API it shares a codebase with, the D1 schema + seed (50 metros, 51 tax jurisdictions, salary percentiles), the community salary-submission flywheel (src/submissions.ts + moderation script in scripts/), and a 206-test vitest suite (npm test).

Run your own

npm install
npx wrangler d1 create kultranz   # then put the id in wrangler.toml
npx wrangler d1 execute kultranz --file schema.sql
npx wrangler d1 execute kultranz --file seed.sql
npm test
npx wrangler deploy

All credentials are environment secrets (RAPIDAPI_PROXY_SECRET, MCP_API_KEY, POLAR_ACCESS_TOKEN, POLAR_PRODUCT_ID) — none are required to run the open MCP endpoint.

Data sources: BLS OEWS · BEA Regional Price Parities · U.S. Census ACS · IRS 2026. Methodology: https://kultranz.com/pages/methodology/?utm_source=github&utm_medium=organic&utm_campaign=revtest-oct · Docs & pricing: https://kultranz.com/pages/api-docs/?utm_source=github&utm_medium=organic&utm_campaign=revtest-oct Open datasets (CC BY 4.0): us-salary-cost-of-living-dataset · 2026-tax-brackets · cost-of-living-index

MIT License. © kultranz.com