Agent Verifier

Verify that the numbers in a finished table add up — before you deliver it. Independent arithmetic audit for AI agents.

GitHub

Hosted MCP Server

npx add-mcp 'https://agent-verifier.agent-verifier.workers.dev/mcp'

Installs into Claude Code, Codex, Cursor and more

Documentation

Agent Verifier

mcp-name: io.github.zenoix888/agent-verifier

Independent arithmetic verification for AI agents — before they deliver their work.

An agent submits a finished table or breakdown. Agent Verifier recomputes every total two independent ways, lists each cell that does not add up (with the recomputed value and the difference), and returns a signed verification receipt: verification ID, UTC timestamp, and a SHA-256 hash of what was checked.

What it checks

  • Tables and spreadsheets (markdown, CSV, TSV)
  • Cost breakdowns, invoices, quotations, budgets
  • Row totals, column totals, subtotals, and line items against a stated total

What it does not check

Arithmetic consistency only. It does not verify that the source data itself is true — and that wording is printed on every receipt:

Arithmetic consistency checked by two independent recomputation paths. Source data accuracy is NOT verified.

It is not a calculator: it does not evaluate expressions, it audits finished numbers.

When to use it

Use Agent Verifier whenever numbers in a finished table have to add up before the table reaches a human:

  • "Check the totals in this spreadsheet / CSV before I send it"
  • "Do these line items add up to the total on the invoice / quotation?"
  • "Cross-foot this table: do the row totals and column totals agree?"
  • "Verify the numbers in this budget / cost breakdown"
  • "Audit this markdown table for arithmetic errors"

If any number does not add up, the response names the exact cell, the value it should be, and the difference — so the agent can fix it before delivery instead of after a human spots it.

Also listed on

Connect

Remote MCP server (streamable HTTP), no authentication required:

  • MCP endpoint: POST https://agent-verifier.agent-verifier.workers.dev/mcp — tool: verify_numbers
  • HTTP API: POST https://agent-verifier.agent-verifier.workers.dev/v1/verify with a JSON body { "content": "<your table or breakdown>" }

Example client configuration:

{
  "mcpServers": {
    "agent-verifier": {
      "url": "https://agent-verifier.agent-verifier.workers.dev/mcp"
    }
  }
}

Pricing

  • Free: 20 checks per day, per caller.
  • After that: US$0.02 per check, paid automatically by the calling agent via the x402 protocol (currently testnet).

Privacy

Zero retention. Submissions are processed in memory only and are never stored or logged. Usage is counted in aggregate only — see the public counters at https://agent-verifier.agent-verifier.workers.dev/stats

This repository

This repo is the public listing home for the hosted service: it holds the registry manifest (server.json) and this documentation. The service itself is hosted at the address above; there is nothing to install.