repairworth-mcp

A Model Context Protocol server (stdio) that runs the calculation engine of the RepairWorth car repair estimate checker from an MCP client. RepairWorth is an independent publication that helps drivers read a US auto repair quote before they pay.

The server works on the amounts written on a quote. It checks that a total agrees with its itemized lines, compares two quotes line by line, rebuilds a towing bill from its own terms, and spreads planned maintenance over a number of months. A fifth tool looks up one state in a dataset of state laws on auto repair estimates.

What it does not do. The server holds no market price and no typical range. It does not say what a repair should cost, and it does not say whether a quote is fair. Every dollar amount in a result was computed from an amount the caller supplied.

The engine is not re-implemented here. The site's engine file is copied unchanged into vendor/, and the test suite checks that each tool returns what the engine returns.

Install

Requires Node.js 18 or later. The package is not on npm yet: install it from this repository.

git clone https://github.com/repairworth/repairworth-mcp.git
cd repairworth-mcp
npm ci

Claude Desktop (claude_desktop_config.json), with the absolute path of your clone:

{
  "mcpServers": {
    "repairworth": {
      "command": "node",
      "args": ["/absolute/path/to/repairworth-mcp/bin/repairworth-mcp.js"]
    }
  }
}

Claude Code:

claude mcp add repairworth -- node /absolute/path/to/repairworth-mcp/bin/repairworth-mcp.js

Related MCP server: macalc

Tools

analyze_quote and compare_quotes run the same functions as the car repair estimate checker linked above. towing_estimate runs the function of the site's towing cost calculator, and maintenance_plan the one of its maintenance cost planner.

Inputs

• A dollar amount is a number, or a string such as "85", "85.50" or "$1,234.50", with two decimals at most.

• A line or a total has a status: fixed (one amount), range (low to high), unknown (the quote gives no amount), included (covered elsewhere) or not-applicable. Only fixed and range carry an amount. The three others are never counted as zero.

• A credit is a positive amount with sign: -1. A refundable charge, such as a core charge, is a line with conditionalRefund: true: it stays out of the total and is reported in the refund fields.

• maintenance_plan takes the services, months and prices from the caller. The engine holds no maintenance schedule and no service interval.

• An unknown key is refused rather than ignored, so a misspelt input cannot change a total silently.

Results

Each of the four calculation tools returns the engine's result unchanged, as JSON. Amounts are integer US cents (displayLowCents: 140000 is $1,400.00).

An input the engine refuses returns isError: true with the engine's own result: valid: false and an errors list whose messages are the ones the site shows. A call the server refuses for its shape (an unknown key, a line that is not an object) returns isError: true with a single error message.

Example: analyze_quote with a total of 1,400 and three lines of 800, 500 and 80 returns, among other fields:

{
  "valid": true,
  "basis": "communicated-total",
  "knownLowCents": 138000,
  "knownHighCents": 138000,
  "displayLowCents": 140000,
  "displayHighCents": 140000,
  "unknown": [],
  "reconciliation": { "lowCents": 2000, "highCents": 2000 }
}

The lines add up to $1,380 and the communicated total is $1,400: $20 of the total is not itemized.

When two quotes are ranges that overlap, compare_quotes returns direction: "overlap" and reports no quote as lower. A price gap only compares like with like when comparableScope is true.

State laws on repair estimates

state_estimate_law takes a two-letter code ("CA", "DC") and returns the row of the dataset as published, in law, with 18 columns: the citation, the official URL, the rules on written estimates, on exceeding the estimate without new consent and on returning replaced parts, a verbatim quote, and the date of the check.

Not legal advice. Verify the official text. The dataset summarizes public legal texts for research and consumer information. Laws change, and a short summary can miss exceptions. Every response repeats this notice in disclaimer.

An empty value means "not established from the source read". It does not mean "no rule". Only state-level law is covered; municipal ordinances are out of scope. The sources behind RepairWorth data are listed on its data sources page.

How the package is built

• vendor/engine.cjs is the site's engine under a two-line notice. vendor/us-state-auto-repair-estimate-laws.csv is the dataset, byte for byte. vendor/SOURCE.json records the SHA-256 of both, and the tests recompute them.

• scripts/sync.mjs is the maintainer's script that refreshes vendor/ and test/vectors.json from the site sources. It refuses to copy a dataset that does not match its published checksum. Nothing else reads outside this package: npm ci && npm test runs from a bare copy of the repository.

• test/vectors.json holds the calls of the engine's own test suite with the answers of the engine source. Each one is replayed through the MCP handler and must come back identical.

npm ci
npm test

License

Three parts, three sets of terms (see LICENSE):

• Server code: MIT.

• Calculation engine (vendor/engine.cjs): all rights reserved, distributed with this package only.

• Dataset (vendor/us-state-auto-repair-estimate-laws.csv): CC BY 4.0. Cite it as: RepairWorth (2026). U.S. State Auto Repair Estimate Laws [Data set].