Skip to content

Counterparty Check

by chtwebllc · remote · no sign-in to list tools · v1.0.1 · published by GitHub user chtwebllc

Check a payee before your agent pays: sanctions, lookalike domains, payment details, invoice fraud.

Final · 2Changes · 1
CompareRegistry entry

4 tools: 2 do something that can't be undone, 1 change things and 1 only read.

Scanned Oct 21, 2026

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

claude mcp add --transport http counterparty-check https://counterpartycheck.com/mcp --header 'Authorization: <your-authorization>'

Findings

Matches of fixed checks, with the text they matched.

2 warn
  • Warncheck_counterparty

    The server marks "check_counterparty" read-only (readOnlyHint: true), and its own name, description or input give the class "irreversible".

    Matched text

    annotations: {"readOnlyHint":true,"openWorldHint":true}; The description's first verb is "run": a word for a change.

    What this check looks for
  • Warnscreen_sanctions

    The server marks "screen_sanctions" read-only (readOnlyHint: true), and its own name, description or input give the class "irreversible".

    Matched text

    annotations: {"readOnlyHint":true,"openWorldHint":true}; The input carries an amount (input.payment.amount) and a currency, so it moves money.

    What this check looks for

Tools

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

4 tools

Can't be undone 2Claude Code: ask
  • check_counterpartyRun a full pre-payment risk check on a payee: OFAC sanctions (names and wallets), domain age and email authentication, lookalike domains (vendor impersonation, brand typo-squats, e…1 finding

    Why it is in this group

    • The description's first verb is "run": a word for a change.
    • The input carries an amount (input.payment.amount) and a currency, so it moves money.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.

    Findings

    • Warn

      The server marks "check_counterparty" read-only (readOnlyHint: true), and its own name, description or input give the class "irreversible".

      Matched text

      annotations: {"readOnlyHint":true,"openWorldHint":true}; The description's first verb is "run": a word for a change.

      What this check looks for
    Description, as the server wrote it
    Run a full pre-payment risk check on a payee: OFAC sanctions (names and wallets), domain age and email authentication, lookalike domains (vendor impersonation, brand typo-squats, executive impersonation), routing/IBAN/SWIFT/wallet validation, and business-email-compromise signals. Returns verdict proceed/review/block, a 0-100 risk score, explained findings, and a signed receipt. Costs $0.25 from the API key balance. Fill in "context" with everything you know about how the payment request arrived; it materially improves fraud detection.

    Annotations the server declares

    • title: Check a payee before paying
    • readOnlyHint: true
    • openWorldHint: true
  • screen_sanctionsScreen a payee name (and optional crypto wallet) against OFAC sanctions lists and embargoed jurisdictions.1 finding

    Why it is in this group

    • The input carries an amount (input.payment.amount) and a currency, so it moves money.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.

    Findings

    • Warn

      The server marks "screen_sanctions" read-only (readOnlyHint: true), and its own name, description or input give the class "irreversible".

      Matched text

      annotations: {"readOnlyHint":true,"openWorldHint":true}; The input carries an amount (input.payment.amount) and a currency, so it moves money.

      What this check looks for
    Description, as the server wrote it
    Screen a payee name (and optional crypto wallet) against OFAC sanctions lists and embargoed jurisdictions. Faster and cheaper than check_counterparty but does not detect fraud patterns. Costs $0.05 from the API key balance; without a key, the first 3 screens each day are free.

    Annotations the server declares

    • title: Sanctions screen only
    • readOnlyHint: true
    • openWorldHint: true
Changes things 1Claude Code: ask
  • verify_receiptConfirm that a receipt returned by a previous check is authentic and unaltered.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.
    • The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
    Description, as the server wrote it
    Confirm that a receipt returned by a previous check is authentic and unaltered. Free.

    Annotations the server declares

    • title: Verify a check receipt
    • readOnlyHint: true
Only reads 1Claude Code: allow
  • check_balanceShow the remaining prepaid balance on the API key used for this connection.No findings

    Why it is in this group

    • The description's first verb is "show": a word for reading.
    Description, as the server wrote it
    Show the remaining prepaid balance on the API key used for this connection. Free.

    Annotations the server declares

    • title: API key balance
    • readOnlyHint: true

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 1.0.1. Values in angle brackets are yours to fill in.

claude mcp add --transport http counterparty-check https://counterpartycheck.com/mcp --header 'Authorization: <your-authorization>'

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__counterparty-check__check_balance"
    ],
    "ask": [
      "mcp__counterparty-check__check_counterparty",
      "mcp__counterparty-check__screen_sanctions",
      "mcp__counterparty-check__verify_receipt"
    ],
    "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 counterparty-check. Review it before you use it.