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FabTally Guard

by zvmzaretsky · remote · no sign-in to list tools · v1.0.0 · published by GitHub user zvmzaretsky

Verify before you act: deps-check, x402-preflight, json-repair & url-read for agents.

Changes · 3
CompareRegistry entry

4 tools: 3 change things and 1 only read.

Scanned Oct 21, 2026

No check matched anything in the tool definitions. No finding is not a safety guarantee. How the checks work.

claude mcp add --transport http fabtally-guard https://guard.fabtally.com/mcp

Tools

Open a tool for its reasons and full description. Descriptions are the publisher's own words, shown as they are.

4 tools

Changes things 3Claude Code: ask
  • deps_checkPAID $0.003 (x402, USDC on Base).No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    Description, as the server wrote it
    PAID $0.003 (x402, USDC on Base). Vet a software package BEFORE installing it. Returns existence, latest-vs-requested, deprecation/yank markers, known CVEs from OSV.dev, typosquat similarity to popular names, SPDX license, and age/download signals with a plain-English risk verdict. Args: ecosystem (npm|pypi|crates), name, version (optional). Without payment returns the x402 challenge; pass x_payment to settle.
  • json_repairPAID $0.002 (x402, USDC on Base).No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    Description, as the server wrote it
    PAID $0.002 (x402, USDC on Base). Coerce near-miss LLM JSON to a JSON-Schema-conformant object: strip code fences/prose, fix trailing commas/quotes/unquoted keys, normalise Python literals, balance brackets, then coerce types, apply defaults, and drop extraneous keys. Returns the repaired object OR precise per-field errors. Args: json (the raw string), schema (a JSON Schema object). Without payment returns the x402 challenge.
  • x402_preflightPAID $0.002 (x402, USDC on Base).No findings

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.
    Description, as the server wrote it
    PAID $0.002 (x402, USDC on Base). Verify another x402 endpoint BEFORE paying it: does an unpaid call return a valid x402 v2 402 challenge? do the quoted amount/asset/network/payTo match the site's /.well-known/x402? is TLS valid, host reachable, openapi present? Returns pass/fail + per-check reasons + the parsed price you would pay. Args: url. Without payment returns the x402 challenge; pass x_payment to settle.
Only reads 1Claude Code: allow
  • url_readPAID $0.004 (x402, USDC on Base).No findings

    Why it is in this group

    • The name "url_read" says "read": a word for reading.
    Description, as the server wrote it
    PAID $0.004 (x402, USDC on Base). Fetch a PUBLIC url and return clean Markdown + a token estimate for RAG ingestion — readability extraction, boilerplate stripped. Respects robots.txt, public pages only, no login/paywall bypass, nothing stored. Args: url. Without payment returns the x402 challenge; pass x_payment to settle.

This is not a safety rating, and no finding is not a safety guarantee. The groups and findings come from fixed checks of the tool definitions the server returned on the date shown, not from its code or what it does when called. How the checks work.

Install

Pinned to version 1.0.0. Values in angle brackets are yours to fill in.

claude mcp add --transport http fabtally-guard https://guard.fabtally.com/mcp

Run in a terminal.

Claude Code permissions

Allow the reads, ask before a change, deny the deletes. Paste into .claude/settings.json.

.claude/settings.json
{
  "permissions": {
    "allow": [
      "mcp__fabtally-guard__url_read"
    ],
    "ask": [
      "mcp__fabtally-guard__deps_check",
      "mcp__fabtally-guard__x402_preflight",
      "mcp__fabtally-guard__json_repair"
    ],
    "deny": []
  }
}

Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. It assumes the server is installed as fabtally-guard. Review it before you use it.