ToolVet
81trust / 100

Simulate

by quartermaster.surewhynot.app in Onchain & crypto

x402 APIPassing, checked 1 h ago

Pre-flight an x402 payment: decode the endpoint's challenge, report the cost on every rail (Base and Solana) and the cheapest, and — with a payer address — verify the wallet can afford the call on Base.

GET https://quartermaster.surewhynot.app/v1/x402/simulate

Last 30 days

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Status and outage history · Atom feed

Uptime
100%
Response time
171 ms typical, 704 ms slowest 5%
Last check
1 h ago
Next check
any minute now

How to call it

GET https://quartermaster.surewhynot.app/v1/x402/simulate

Each call costs $0.003 in USDC on Base, paid with the request over x402.

Run a free test callOne unpaid request, the way an agent sends it. You see the payment challenge it gets back. Nothing is charged.

Example request

From the listing.

GET https://quartermaster.surewhynot.app/v1/x402/simulate?address=0xc2a36e22ecbf353086cf83e7beea78bc28a64083&url=https%3A%2F%2Fapi.example.com%2Fpaid-endpoint

Parameters

ParameterTypeRequiredDescription
addressstringNoOptional payer wallet to check Base affordability
urlstring (uri)YesThe x402 endpoint to pre-flight

Example response

The provider's example. We can't check it without paying.

Example response, 36 lines
{
  "affordability": {
    "address": "0xc2a3...4083",
    "can_afford": true,
    "cost_usdc": "0.005",
    "rail_checked": "evm",
    "usdc_balance": "1.234"
  },
  "cheapest": {
    "cost_usdc": "0.005",
    "network": "eip155:8453",
    "rail": "evm"
  },
  "is_x402": true,
  "payable": true,
  "rails": [
    {
      "asset_name": "USDC (Base mainnet)",
      "cost_usdc": "0.005",
      "network": "eip155:8453",
      "network_name": "Base mainnet",
      "pay_to": "0x...",
      "rail": "evm"
    },
    {
      "asset_name": "USDC (Solana)",
      "cost_usdc": "0.005",
      "network": "solana:5eykt4...",
      "network_name": "Solana mainnet",
      "pay_to": "...",
      "rail": "svm"
    }
  ],
  "url": "https://api.example.com/paid-endpoint",
  "warnings": []
}

Call it from code

The curl command shows the payment challenge. The JavaScript and Python versions pay and call, and never pay more than $0.003.

curl: see the payment challenge
# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://quartermaster.surewhynot.app/v1/x402/simulate?address=0xc2a36e22ecbf353086cf83e7beea78bc28a64083&url=https%3A%2F%2Fapi.example.com%2Fpaid-endpoint'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - 'https://quartermaster.surewhynot.app/v1/x402/simulate?address=0xc2a36e22ecbf353086cf83e7beea78bc28a64083&url=https%3A%2F%2Fapi.example.com%2Fpaid-endpoint' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode
JavaScript: pay and call
// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.003 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.003" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.003 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fquartermaster.surewhynot.app%2Fv1%2Fx402%2Fsimulate
const res = await pay("https://quartermaster.surewhynot.app/v1/x402/simulate?address=0xc2a36e22ecbf353086cf83e7beea78bc28a64083&url=https%3A%2F%2Fapi.example.com%2Fpaid-endpoint");
console.log(res.status, await res.text());
Python: pay and call
# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.003 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.003"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://quartermaster.surewhynot.app/v1/x402/simulate?address=0xc2a36e22ecbf353086cf83e7beea78bc28a64083&url=https%3A%2F%2Fapi.example.com%2Fpaid-endpoint")
    print(res.status_code, res.text)

Security scan

  • No findings. We scan names, descriptions and tool definitions for hidden instructions and other prompt-injection patterns.

Recent checks

WhenResultHTTPTimePrice
1 h agoPassed402636 ms$0.003
5 h agoPassed402704 ms$0.003
9 h agoPassed402118 ms$0.003
13 h agoPassed402128 ms$0.003
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36 h agoPassed402652 ms$0.003
40 h agoPassed402135 ms$0.003
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47 h agoPassed402127 ms$0.003
2 days agoPassed402171 ms$0.003
2 days agoPassed402556 ms$0.003