Swap Safety Check

{
  "allowance": {
    "status": "wallet_required_for_check"
  },
  "amount": {
    "human": "25",
    "raw": "25000000",
    "usdcEquivalentRaw": "25000000"
  },
  "chainId": 8453,
  "checkId": "00000000-0000-4000-8000-000000000000",
  "createdAt": "2026-01-01T00:00:00.000Z",
  "estimatedOutput": {
    "raw": "10000000000000000"
  },
  "expectedSafeRouteFee": {
    "amountRaw": "12500",
    "bps": 10,
    "indicative": true,
    "token": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
  },
  "expiresAt": "2026-01-01T00:01:00.000Z",
  "liquidity": {
    "available": true,
    "sources": [
      "Uniswap_V3"
    ]
  },
  "nextAction": {
    "endpoint": "https://api.usesaferoute.com/v1/quote",
    "method": "POST",
    "price": "$0.01",
    "requiredAdditionalField": "wallet"
  },
  "pair": {
    "buyToken": "0x4200000000000000000000000000000000000006",
    "from": "USDC",
    "sellToken": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
    "to": "WETH"
  },
  "priceImpact": {
    "status": "checked_on_full_quote",
    "warning": "Price impact is calculated on the full wallet-bound quote."
  },
  "status": "eligible",
  "tokenVerification": {
    "buyTokenApproved": true,
    "buyTokenDecimals": 18,
    "sellTokenApproved": true,
    "sellTokenDecimals": 6
  },
  "warnings": [
    "Indicative preflight only; output and route are refreshed before a full quote."
  ]
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://api.usesaferoute.com/v1/swap-safety-check' \
  -H 'content-type: application/json' \
  --data-raw '{"amount":"25","from":"USDC","intentId":"intent_unique_1234567890","sourceAgentId":"buyer-agent-id","to":"WETH"}'

# 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.usesaferoute.com/v1/swap-safety-check' \
  -H 'content-type: application/json' \
  --data-raw '{"amount":"25","from":"USDC","intentId":"intent_unique_1234567890","sourceAgentId":"buyer-agent-id","to":"WETH"}' \
  | 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 $0.001 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.001" });
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 $0.001 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fapi.usesaferoute.com%2Fv1%2Fswap-safety-check&method=POST
const res = await pay("https://api.usesaferoute.com/v1/swap-safety-check", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "amount": "25",
    "from": "USDC",
    "intentId": "intent_unique_1234567890",
    "sourceAgentId": "buyer-agent-id",
    "to": "WETH"
  }),
});
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 $0.001 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.001"})
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.usesaferoute.com/v1/swap-safety-check",
        json={
            "amount": "25",
            "from": "USDC",
            "intentId": "intent_unique_1234567890",
            "sourceAgentId": "buyer-agent-id",
            "to": "WETH",
        },
    )
    print(res.status_code, res.text)