Before the Lot

com.beforethelotPublished by beforethelot.comOfficial publisherv1.0.0Updated Oct 29, 2026

Car-buying math and state rules: out-the-door prices, quote checks, leases and trade-ins

VerifiedStreamable HTTPWeb executableFinanceBusiness & Commerce

Overview

AI-generated overview

Free car-buying calculator that lets an assistant work out out-the-door prices, check dealer quotes, compare leases, loans and trade-ins, and look up state…

What you can do
  • Work out budgets and prices: monthly-payment ceiling, itemized out-the-door estimate, loan payment, payoff plan
  • Check and compare dealer quotes line by line, rank two to ten quotes, and weigh a cash rebate against a special APR
  • Evaluate financing: lease quote from residual and money factor, refinance comparison, trade-in position against written offers
  • Look up state rules on doc fees, sales tax, trade-in tax credit and rebate taxation, and get the maker's offers page
  • Draft dealer emails from six templates and desk scripts for moments at the dealership, and build a prefilled planner link
  • Explain the seven-stage buying method and what each stage produces
When to use it
Useful when someone is shopping for a car and wants help with the arithmetic and paperwork: setting a budget and walk line, sanity-checking a dealer's out-the-door quote, comparing quotes or financing options, or checking a state's fee and tax rules before negotiating.
Requirements
Remote MCP endpoint at beforethelot.com over streamable HTTP; no package, account, API key or environment variable is declared. The assistant needs network access to that endpoint.
Before you install
Results are educational estimates, not financial, legal or tax advice, and the tools describe and compare numbers without recommending a choice. Inputs are limited to numbers and short labels: names, phone numbers and email addresses are refused, and nothing is stored. Planner links carry the numbers in the link itself, so anyone with the link can see them.

Installation

In SourceWeft

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

Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.

Use with an agent

Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.

Read https://sourceweft.com/mcp/com.beforethelot%2Fbefore-the-lot/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.

Read the install guide the agent follows

Other MCP clients

Add this to your client's mcpServers config.

{
  "mcpServers": {
    "before-the-lot": {
      "type": "http",
      "url": "https://beforethelot.com/mcp"
    }
  }
}

Tools

16

what_can_i_afford

What can I afford

Works out the budget ceiling from a monthly payment: the most that can be financed, the highest out-the-door price after the trade-in tax credit, that ceiling as dealers quote it (before the trade-in credit), and the vehicle price it leaves after the state's tax and typical fees. With a fair price from research, it also gives an opening offer and a walk line. Numbers only; nothing is stored.

Parametersaprrequiredcitydownstaterequiredcountydoc_feeinvoicetax_rateconditiontitle_regfair_pricemax_paymentrequired+3 more

out_the_door

Out-the-door estimate

Itemizes an out-the-door estimate for a vehicle price: rebates, doc fee, add-ons, the state's sales tax (with its rules on rebates and caps), title and registration. Optionally adds a trade-in (and the tax it saves where the state credits it), a down payment and a loan for the payment. Compares the doc fee with the state's cap and the total with a walk line.

Parametersaprcitydownpricerequiredstaterequiredcountyadd_onsdoc_feerebatescity_mpgelectrictax_rate+10 more

check_quote

Check a dealer's quote

Reads a dealer's out-the-door quote, pasted as text (up to 8 KB) or given as line items, and checks it line by line: the out-the-door total, the doc fee against the state's cap (and capped service fees such as Ohio's $50 convenience fee), the tax line against the state's rate, finance-office add-ons with typical prices, the trade allowance against written trade-in offers, the trade equity and amount financed, and the walk line. Lines with an email address or phone number are removed before reading and never returned. Nothing is stored.

Parameterstextlinesstaterequiredtax_ratewalk_linetrade_offerstrade_allowancebest_trade_offer

compare_quotes

Compare dealer quotes

Ranks two to ten itemized dealer quotes by out-the-door price, with each one's gap to the lowest and to the walk line, and (with a state) each doc fee against the state's cap.

Parametersstatequotesrequiredwalk_line

rebate_vs_apr

Cash rebate or special APR

Compares a maker's cash rebate taken with the person's own loan against the maker's special APR (with any cash that combines with it): each side's payment, interest and total, the difference, the own-loan rate where the two cost the same, and the sales tax a rebate saves in states that tax the price after it. Give the amount financed before the rebate, or a vehicle price to work it out.

Parameterscitydownstaterequiredcountyrebaterequireddoc_feeown_aprrequiredtax_ratepromo_aprrequiredtitle_regpromo_cashterm_monthsrequired+5 more

loan_payment

Loan payment

The monthly payment, total interest and total paid on a car loan, with what a term over 60 months adds in interest compared with 60.

Parametersaprrequiredamountrequiredterm_monthsrequired

lease_check

Check a lease

Works a lease quote from MSRP, selling price, residual and money factor (or the lease's APR): the depreciation and rent charges, the payment with tax (and a state lease tax on top where there is one, such as Pennsylvania's 3%; Alabama's 1.5% and West Virginia's 5% lease-payment rates in place of their sales rates; in states that tax a lease once at the start, such as Texas and Ohio, the payment carries no tax and the result says so), the money factor as an APR, and the total cost. With a loan APR and term, it also compares leasing with buying the same car over the lease's months (on a labelled depreciation assumption).

Parameterscityfeesmsrprequiredstaterequiredcountybuy_aprdoc_feebuy_downtax_ratelease_aprterm_monthsrequiredmoney_factor+6 more

refinance_check

Check a refinance

Compares a car loan as it stands with a new loan at a quoted rate, by default over the same months left so a lower payment cannot hide a longer loan, with any fees counted: the new payment, the monthly difference and the total interest saved or added.

Parametersfeesbalancerequirednew_aprrequiredcurrent_aprrequiredcurrent_paymentrequirednew_term_months

trade_in_position

Trade-in position

From written trade-in offers and the payoff: the best offer still open (the floor a dealer's trade number is compared with), the equity or negative equity, and, with a state and vehicle price, the sales tax the trade saves where the state credits it.

Parameterscitystatecountyoffersrequiredpayoffdoc_feetax_ratevehicle_price

payoff_plan

Payoff plan

A payoff plan for a car loan, for paying it off early with an extra payment each month: the months and total interest at the regular payment, and with an extra amount toward principal each month (optionally for only the first so many months, or skipping some), with the months and interest the extra saves and the payoff month each way. Give the balance, the APR, and the months left or the regular payment. Lenders differ in how they apply extra payments, and some charge a prepayment penalty.

Parametersaprrequiredbalancerequiredpaymentmonths_leftskip_monthsextra_monthlyrequiredextra_for_months

get_method

Get the Before the Lot method

The Before the Lot method: an overview and its seven stages (what to collect, what each produces, which guides, tools and email templates apply, and when the stage is done). Pass a stage id for one stage.

Parametersstage

state_rules

State rules for buying a car

A state's rules on dealer doc fees, sales tax (state rate, local add-on range, cap), trade-in tax credit, how a maker's rebate is taxed, and cancellation rights where on file, each with its source, as-of date and confidence, plus the link to the state's page.

Parametersstaterequired

dealer_email

Draft an email to a dealer or lender

Fills one of the six Before the Lot email templates (request a quote, make an offer, a competing quote, confirm the deal, decline, tell a lender) with the details given and returns the subject and body. Details are numbers and short labels; contact details are refused.

Parameterskindrequireddetails

offers_page

A maker's official offers page

Where a maker lists its own current offers (and a model's own page where one can be built), with whether the maker lists national offers at all.

Parametersmakerequiredmodel

desk_script

A line to say at the dealership

The Before the Lot line for a moment at the desk. Pass a script id (monthly-payment, trade-first, down-payment, credit-check, numbers-changed, preinstalled-add-ons, initial-worksheet, decide-today, beat-my-rate, fi-product, only-a-month, paint-or-markup, below-invoice, trade-below-offer, leaving) or a short description of the situation.

Parameterssituationrequired

Version history

1
  1. v1.0.0LatestOct 29, 2026

Score

83% 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 daysRequired25 pts
  • Auth declaredRequired10 pts
  • Tools listedRequired15 pts
  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts

    Declare a GitHub repository with a README, or serve resource_documentation in the OAuth protected-resource metadata.

  • LicenseNot applicable

    A hosted service is used under its provider's terms, so no license is expected here. This check is left out of the percentage.