Pretrade Check

{
  "block_number": 35000000,
  "buy_ok": true,
  "buy_tax_pct": 0,
  "cached": false,
  "chain": "base",
  "chain_id": 8453,
  "disclaimer": "Informational, not financial advice. Simulation of a hypothetical buy/transfer/sell against public Base state at the stated block; it is not a guarantee that a real trade will succeed or be taxed the same way (token owners can change rules at any time). Heuristic flags can be wrong; do your own research.",
  "gas": {
    "buy": 150000,
    "sell": 133537,
    "transfer": 40000
  },
  "pool": "0xBA3F945812a83471d709BCe9C3CA699A19FB46f7",
  "product": "pretrade-check",
  "reasons": [
    "buy, transfer and sell simulated successfully with < 1% tax"
  ],
  "revert_reason": null,
  "risk_flags": [
    {
      "flag": "HAS_ACTIVE_OWNER",
      "note": "contract has an active (non-renounced) owner"
    }
  ],
  "route": "uniswap_v3:fee_10000 WETH",
  "schema_version": "1.0",
  "sell_ok": true,
  "sell_tax_pct": 0,
  "status": "ok",
  "token": "0x532f27101965dd16442E59d40670FaF5eBB142E4",
  "token_check_risk_level": "low",
  "transfer_ok": true,
  "transfer_tax_pct": 0,
  "verdict": "ok"
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://api.x402risk.com/v1/pretrade-check' \
  -H 'content-type: application/json' \
  --data-raw '{"amount_usd":100,"token":"0x532f27101965dd16442E59d40670FaF5eBB142E4"}'

# 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 - -X POST 'https://api.x402risk.com/v1/pretrade-check' \
  -H 'content-type: application/json' \
  --data-raw '{"amount_usd":100,"token":"0x532f27101965dd16442E59d40670FaF5eBB142E4"}' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode

// 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 $0.02 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.02" });
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 $0.02 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fapi.x402risk.com%2Fv1%2Fpretrade-check&method=POST
const res = await pay("https://api.x402risk.com/v1/pretrade-check", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "amount_usd": 100,
    "token": "0x532f27101965dd16442E59d40670FaF5eBB142E4"
  }),
});
console.log(res.status, await res.text());

# 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 $0.02 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.02"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.post(
        "https://api.x402risk.com/v1/pretrade-check",
        json={
            "amount_usd": 100,
            "token": "0x532f27101965dd16442E59d40670FaF5eBB142E4",
        },
    )
    print(res.status_code, res.text)