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PayCheck

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

Score merchant domain, https URL, or 0x wallet trust before an agent pays. Does not send payments.

Changes · 2
CompareRegistry entry

3 tools: 2 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 paycheck https://paycheck.toolweather.workers.dev/mcp

Findings

Matches of fixed checks, with the text they matched.

1 warn1 info
  • Warnget_api_key

    The server marks "get_api_key" as not read-only (readOnlyHint: false), and its words say it reads.

    Matched text

    annotations: {"readOnlyHint":false,"destructiveHint":false,"idempotentHint":false,"openWorldHint":false}; The name "get_api_key" says "get": a word for reading.

    What this check looks for
  • Infocheck_merchant

    The description is 2,143 characters long, over the 2,000 this check looks for.

    Matched text

    description ends: "...d. If PAY_TO is unset, an over-cap check returns HTTP 402 payment_not_configured."

    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.

3 tools

Changes things 2Claude Code: ask
  • check_merchantDecide whether an autonomous agent should pay a merchant, host, or wallet.1 finding

    Why it is in this group

    • Nothing in its name or description says what it does, so it is counted as a write.

    Findings

    • Info

      The description is 2,143 characters long, over the 2,000 this check looks for.

      Matched text

      description ends: "...d. If PAY_TO is unset, an over-cap check returns HTTP 402 payment_not_configured."

      What this check looks for
    Description, as the server wrote it
    Decide whether an autonomous agent should pay a merchant, host, or wallet. PayCheck returns a deterministic trust score for one target. It does not send money, does not sign transactions, and does not hold wallet keys. Use this immediately before a payment, a checkout redirect, or a transfer to a new 0x address. Pass the payee as a bare domain (api.openai.com), an https URL, or a 0x address with 40 hex characters. Do not use this tool to execute a payment. Do not use it to overturn a block. Do not call it again with a reworded category, purpose, or amount to fish for a better verdict: those fields are ignored and are not stored. Trusted is returned only for the published allowlist of known AI and developer APIs, served over https on port 443. A new or random domain is never trusted. A wallet is never trusted. Scoring v1 does not analyze on-chain history. If the URL contains an embedded 0x address, this scores the host only and will not return trusted; pass the bare address to score the wallet. Arguments: target (required string); amount_usd (optional number, ignored); category (optional string, ignored); api_key (optional pc_live_ key). You may also send Authorization: Bearer or X-API-Key. Omit the key for the anonymous allowance. Returns: score (integer 0-100), verdict (trusted | unknown | suspicious | block), reasons[], recommended_action (proceed | verify_out_of_band | require_human_review | do_not_pay), signals (host, allowlist, domain age, wallet flags, reason_codes; chain_analysis is always not_in_v1), checked_at (ISO-8601), policy_version ("1"). Free tier: 100 checks per UTC day anonymous, 1,000 per UTC day with a free pc_live_ key or a Toolweather bundle client whose x-tw-bundle-client is hex. A bundle client prefixed anon: stays at 100 per day. The same target for the same caller is idempotent for 60 seconds and does not consume a second check. Over the daily cap, each extra check is $0.001 USDC on Base (eip155:8453) via x402 and the PayAI facilitator. get_quota, get_api_key, docs, and MCP discovery are not billed. If PAY_TO is unset, an over-cap check returns HTTP 402 payment_not_configured.

    Annotations the server declares

    • title: Check merchant
    • readOnlyHint: false
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: true
  • get_api_keyMint one free PayCheck API key.1 finding

    Why it is in this group

    • The name "get_api_key" says "get": a word for reading.
    • The server marks it as not read-only (readOnlyHint: false).

    Findings

    • Warn

      The server marks "get_api_key" as not read-only (readOnlyHint: false), and its words say it reads.

      Matched text

      annotations: {"readOnlyHint":false,"destructiveHint":false,"idempotentHint":false,"openWorldHint":false}; The name "get_api_key" says "get": a word for reading.

      What this check looks for
    Description, as the server wrote it
    Mint one free PayCheck API key. The key looks like pc_live_ followed by hex and raises the merchant-check allowance from 100 to 1,000 per UTC day. Use this once when you set up a long-running agent, then store the key and pass it on later check_merchant or get_quota calls. The plaintext key is returned only in this response. PayCheck stores a SHA-256 hash. Do not call this every turn. Do not call it to score a payee or to dodge a block verdict. Minting is free and is not an x402 check, and it is limited to 10 new keys per caller IP per UTC day. A new key does not change any merchant score. Checks above the free daily cap still cost $0.001 USDC on Base via x402. Returns: api_key, token_type (bearer), daily_limit (1000), prefix, note.

    Annotations the server declares

    • title: Get API key
    • readOnlyHint: false
    • destructiveHint: false
    • idempotentHint: false
    • openWorldHint: false
Only reads 1Claude Code: allow
  • get_quotaShow how many free PayCheck merchant checks the current caller has left for the current UTC day.No findings

    Why it is in this group

    • The name "get_quota" says "get": a word for reading.
    Description, as the server wrote it
    Show how many free PayCheck merchant checks the current caller has left for the current UTC day. Use this before a batch of check_merchant calls, or after an HTTP 402, to read the remaining free allowance and when it resets. Do not use this to score a payee. It accepts no target and it does not consume a check. Do not pay x402 for this tool. It is always free. Identity matches check_merchant. Anonymous IP: 100/day. pc_live_ api_key (api_key argument, Authorization: Bearer, or X-API-Key): 1,000/day. Toolweather bundle headers x-tw-bundle-secret and x-tw-bundle-client: hex client 1,000/day, anon: prefix 100/day, any other client id 100/day. Returns: subject_kind, limit, used, remaining, resets_at (next UTC midnight, ISO-8601), billed (always false), policy_version. No x402 charge.

    Annotations the server declares

    • title: Get quota
    • readOnlyHint: true
    • destructiveHint: false
    • idempotentHint: true
    • openWorldHint: false

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 paycheck https://paycheck.toolweather.workers.dev/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__paycheck__get_quota"
    ],
    "ask": [
      "mcp__paycheck__check_merchant",
      "mcp__paycheck__get_api_key"
    ],
    "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 paycheck. Review it before you use it.