# tollbooth-x402 [Health: Active]

**Category:** 💰 Finance & Fintech  
**Repository:** https://github.com/SolomonisBlack/tollbooth-x402  
**GitHub Stars:** 0  
**Views:** 3  
**Installs:** 0  
**Upvotes:** 0  
**Directory Page:** https://allmcps.com/mcp/tollbooth-x402

## Description
Discover, preview & self-verify 56 x402 pay-per-call finance/tax calculators for AI agents.

## Tools
Capabilities this server exposes over MCP:

- **tollbooth_catalog**
- **tollbooth_preview**
- **tollbooth_verify_hash**
- **tollbooth_how_to_pay**

## Claude Desktop Quick Installation
Install path detected from listing signals. Uses `npx` (confidence: high):

```json
"mcpServers": {
  "tollbooth-x402": {
    "command": "npx",
    "args": ["-y","tollbooth-x402"]
  }
}
```

## Documentation

## What the tollbooth-x402 MCP server does

The tollbooth-x402 MCP server connects MCP clients to a catalog of verified, pay-per-call calculators for AI agents. The catalog covers tax and payroll, crypto and DeFi, lending, real estate, retirement, and business calculations. The README describes 56 available calculators, including tools for paycheck estimates, self-employment tax, capital gains, mortgage affordability, LLC costs, debt plans, and impermanent loss.

The MCP layer itself provides discovery and verification functions. Calculator endpoints may require payment, while the MCP tools listed in the README are free to use and do not require a wallet.

## How it works

An agent can first inspect the catalog to learn which endpoints exist, how much each costs, which method it uses, and what input schema it expects. It can then request a coarse, rounded preview before deciding whether a paid calculation is appropriate. After a paid response is returned, the agent can re-derive its hash with the verification tool to check that the response was not altered.

Payment follows the x402 protocol. Paid requests go directly to `https://x402toll.com`, use USDC on Base, and are handled by an x402-capable wallet or client. The README states that these calls do not require an account or API key. The `tollbooth_how_to_pay` tool explains the payment flow to an agent.

## Setup and configuration

Install the tollbooth-x402 MCP server with:

```bash
npx -y tollbooth-x402
```

An MCP client configuration can run it through `npx`. The README specifically gives Claude Desktop and Cursor as example clients. The server uses the default x402toll.com gateway unless `TOLLBOOTH_URL` is set to a different gateway.

## Tools and capabilities

The tollbooth-x402 MCP server exposes four tools:

- `tollbooth_catalog`: Lists endpoints with prices, input schemas, methods, and golden-vector evidence.
- `tollbooth_preview`: Produces a free rounded preview for supported calculator types.
- `tollbooth_verify_hash`: Recomputes a paid response's hash for provenance checking.
- `tollbooth_how_to_pay`: Describes how to pay for protected endpoints with x402.

Each calculator response is described as including a formula trace and a reproducible SHA-256 hash. The catalog's golden-vector evidence supports reviewing the available reference checks before making a paid request.

## Limitations and notes

The previews are coarse and rounded, so they should not be treated as substitutes for paid results. The listed calculators are estimates only and are not financial, legal, or tax advice. Paid calls require an x402-capable wallet or client with the ability to make the required USDC payment on Base; the MCP server does not remove that payment requirement.

The calculations are intended to reflect exact 2026 data such as tax brackets, contribution limits, and state fees, but users should still validate outputs for their own circumstances. Changing `TOLLBOOTH_URL` points the client at another gateway, so that gateway must provide the expected compatible service.

_Full upstream README: https://allmcps.com/mcp/tollbooth-x402/readme_