Tollbooth X402

io.github.SolomonisBlackPublished by GitHub account SolomonisBlackv0.6.0Updated Oct 24, 2026

Discover, quote, verify & self-check 56 x402 pay-per-call finance/tax calculators for AI agents.

VerifiedSTDIODesktop onlyFinance Business & Commerce

Server details

Identifier: io.github.SolomonisBlack/tollbooth-x402
Transport: STDIO
Runtime: Desktop only
Trust: Verified
Published: Sep 16, 2026

Security note

MCP servers receive tool arguments from a conversation and may perform external actions. Review what a server can do before you enable it, and give it only the access it needs.

The registry verified the GitHub account SolomonisBlack for this listing. That does not show the account is the product's maker.

SourceWeft's checks cover whether the listing is complete and the endpoint answered; they do not review the server's code or what its tools do.

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Overview

AI-generated overview

A free local MCP server that lets an assistant browse and preview 56 pay-per-call x402 finance and tax calculators, verify paid answers, and learn the payment.

What you can do: Browse the calculator catalog with prices, input schemas, methods and golden-vector evidence, and get the x402 payment flow for paid endpoints. Run free rounded previews of calculators such as paycheck, self-employment tax, capital gains, mortgage affordability, LLC cost, debt plan and impermanent loss. Re-derive a paid response's hash to confirm it was not altered. Paid calls themselves are made directly against the x402toll.com gateway by an x402-capable wallet or client, not by this server.
When to use it: Useful when an assistant needs 2026-dependent finance or tax figures (brackets, contribution limits, state fees) that a model cannot reliably know, and you want to inspect the catalog and free previews before deciding whether to pay for exact answers.
Requirements: Runs locally via npx, so Node.js is needed. No account, API key or wallet is required for the free tools. Paid endpoints need an x402-capable wallet or client paying a few cents of USDC per call on Base. The optional TOLLBOOTH_URL variable points at a different gateway.

Before you install

Paid endpoints spend real USDC per call through an external wallet or client, so costs accrue outside this server. Answers are estimates only, not financial, legal or tax advice. Requests go to the third-party x402toll.com gateway, which can be redirected with TOLLBOOTH_URL.

Installation

In SourceWeft

Open Tollbooth X402 in the dashboard and add it to a workspace.
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

tollbooth-x402

Free MCP server for x402toll.com — a toll plaza of verified, pay-per-call calculators for AI agents. Discover the catalog, run free coarse previews, verify any paid response's provenance hash, and learn how to pay. The paid endpoints charge a few cents of USDC per call over the x402 protocol on Base — no account, no API key.

Why agents pay: the answers depend on exact 2026 data (tax brackets, contribution limits, state fees) a model can't reliably know, every answer is checked against hand-verified reference values, and each ships with a formula trace and a reproducible SHA-256 hash.

Install

Add to an MCP client (e.g. Claude Desktop / Cursor):

Tools (all free, no wallet)

tollbooth_catalog — every endpoint with prices, input schemas, methods, and golden-vector evidence.
tollbooth_preview — a free rounded preview of a tool (paycheck, self-employment tax, capital gains, mortgage affordability, LLC cost, debt plan, impermanent loss).
tollbooth_verify_hash — re-derive a paid response's hash to confirm it wasn't altered.
tollbooth_how_to_pay — the x402 payment flow for the paid endpoints.

Paid calls are made directly against https://x402toll.com by an x402-capable wallet/client. Set TOLLBOOTH_URL to point at a different gateway.

Tools

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

Version history

v0.6.0LatestSep 16, 2026

Score

40% 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
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Auth declared10 pts
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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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