MoneyTools · all products

Agent payment-safety suite

Four existing MoneyTools products, used in a fixed order when an AI agent is about to pay. We never hold, move, or sign funds. Settle spend caps are advisory: they cannot block a wallet payment.

Suggested path: Precheck the seller → Settle spend/check against the budget → if the action is high-risk or over a threshold, ask a human via Approval Relay → pay with your own wallet (or Pay Gateway) → record it on Spend Ledger.

The four products

Pay Gateway step-up approvals (0.005 USDC) remain at approve.moneytools.dev for existing callers. New integrations should use Approval Relay.

Client wrapper (copy-paste snippet)

To plug Pay Precheck and Settle spend caps into any x402 client, wrap the underlying fetch, axios, requests or httpx session inside your payment wrapper. The hook inspects a 402, may refuse it, and otherwise returns the 402 so the outer client can sign. It never loads a key or sends a payment. Not published to npm or PyPI; copy the file.

Download: x402-guard.ts · x402-guard.py. Source and tests: in-repo sdk/x402-guard/.

import { wrapFetch } from "./x402-guard.ts";
// const paid = wrapFetchWithPayment(wrapFetch(fetch, { payer, maxUsd: 0.05 }), wallet);
const guarded = wrapFetch(fetch, { payer: "0xYourAgentWallet", maxUsd: 0.05, escalate: "high" });
const res = await guarded("https://seller.example/data");

Python: wrap_requests(session, {"payer": payer, "max_usd": 0.05}) or wrap_httpx(client, ...). Set a User-Agent; default Python-urllib is blocked on some workers.dev hosts. If Pay Precheck or Settle itself returns 401/402, the hook fails closed and does not pay MoneyTools automatically (pass apiKey or wait for the daily free-tier reset).

Shared examples (manual hook)

A shorter, call-it-yourself beforePay sketch: TypeScript suite.ts · Python suite.py.

// MoneyTools payment-safety suite — suggested order for an agent about to pay.
// Free tiers (live, UTC day): Pay Precheck HTTP 5/IP/endpoint, MCP 20/client;
// Approval Relay 3/day; Settle free trial 50 calls / 7 days (or 0.005 USDC per check).
// This snippet does not sign a wallet or send a payment.

const PRECHECK = "https://api.moneytools.dev/v1/precheck?utm_source=guide";
const SETTLE = "https://settle.moneytools.dev/v1/spend/check";
const RELAY = "https://relay.moneytools.dev/v1/approvals";
const LEDGER = "https://ledger.moneytools.dev/v1/ledger?utm_source=guide";

export async function beforePay({ sellerUrl, payer, amountUsd, host, risk = "med" }: {
  sellerUrl: string; payer: string; amountUsd: string; host: string; risk?: "low" | "med" | "high";
}) {
  const pre = await fetch(`${PRECHECK}?url=${encodeURIComponent(sellerUrl)}`).then((r) => r.json());
  if (pre.verdict === "block" || pre.ok === false) return { proceed: false, step: "precheck", pre };

  const cap = await fetch(SETTLE, {
    method: "POST",
    headers: { "content-type": "application/json" },
    body: JSON.stringify({ payer, amountUsd, host }),
  }).then((r) => r.json());
  if (cap.allow === false) return { proceed: false, step: "spend_check", cap };

  const needsHuman = risk === "high" || cap.allow === false;
  if (needsHuman) {
    const appr = await fetch(RELAY, {
      method: "POST",
      headers: { "content-type": "application/json" },
      body: JSON.stringify({
        action_summary: `Pay ${amountUsd} USDC to ${host} at ${sellerUrl}`,
        risk,
        expires_in_s: 3600,
      }),
    }).then((r) => r.json());
    return { proceed: false, step: "approval_relay", approve_url: appr.approve_url, approval_id: appr.approval_id, poll_url: appr.poll_url };
  }

  return { proceed: true, pre, cap };
}

// After you pay

Free-tier cheat sheet (live, do not assume one number for every host)

• Pay Precheck HTTP: 5 free calls per IP per /v1 endpoint per UTC day. MCP: 20 free tool calls per client per UTC day (first call always free; invalid arguments are not counted).
• Approval Relay: 3 free create-requests per day (status / receipt / verify stay free).
• tools.moneytools.dev: 10 free calls per tool per client per UTC day, 20 free calls total per client across all tools (HTTP + MCP combined). Optional free key: 100/day.
• Status find / reputation HTTP: 3 free calls per IP per day. Status MCP paid tools: 10 free/day.

Agents: site llms.txt · Precheck llms · Settle llms · Relay llms · Ledger llms · Terms · Privacy · support@moneytools.dev