Batch

{
  "count": 1,
  "results": [
    {
      "blockNumber": "52159737",
      "disclaimer": "eth_call simulation at block 52159737: a small buy with WETH and an immediate sell on the token's deepest WETH pools. Not a guarantee: the token's code or owner can change, and some tokens treat addresses or sizes differently. Not financial advice.",
      "flags": [
        {
          "fact": "Bought with 0.01 WETH and sold straight back on uniswap-v3 pool 0x6c561B446416E1A00E8E93E221854d6eA4171372 at block 52159737 (eth_call simulation): round-trip loss 0.6%, which includes a 0.30% pool fee paid twice and any token tax.",
          "id": "sell_ok",
          "severity": "info"
        }
      ],
      "name": "USD Coin",
      "simulation": {
        "amounts": {
          "tokenReachedPool": null,
          "tokenReceived": "26912247",
          "tokenReleasedByPool": "26912247",
          "tokenSent": "26912247",
          "wethOut": "9940089592377343"
        },
        "attempts": [
          {
            "dex": "uniswap-v3",
            "fee": 3000,
            "ok": true,
            "pool": "0x6c561B446416E1A00E8E93E221854d6eA4171372",
            "wethIn": "10000000000000000"
          }
        ],
        "buyTaxPct": 0,
        "dex": "uniswap-v3",
        "fee": 3000,
        "pool": "0x6c561B446416E1A00E8E93E221854d6eA4171372",
        "roundTripLossPct": 0.6,
        "sellTaxPct": null,
        "status": "ok",
        "wethIn": "10000000000000000"
      },
      "source": "base-mainnet-rpc",
      "summary": "USDC: Simulated buy and sell on uniswap-v3: no transfer tax, round-trip loss 0.6%.",
      "symbol": "USDC",
      "token": "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913"
    }
  ],
  "skipped": [
    {
      "reason": "not a contract",
      "token": "0x0000000000000000000000000000000000000001"
    }
  ]
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://base-facts.yankii.fr/v1/batch' \
  -H 'content-type: application/json' \
  --data-raw '{"tokens":["0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","0x4200000000000000000000000000000000000006"]}'

# 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://base-facts.yankii.fr/v1/batch' \
  -H 'content-type: application/json' \
  --data-raw '{"tokens":["0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","0x4200000000000000000000000000000000000006"]}' \
  | 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 $0.03 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.03" });
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 $0.03 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fbase-facts.yankii.fr%2Fv1%2Fbatch&method=POST
const res = await pay("https://base-facts.yankii.fr/v1/batch", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "tokens": [
      "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
      "0x4200000000000000000000000000000000000006"
    ]
  }),
});
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 $0.03 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.03"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.post(
        "https://base-facts.yankii.fr/v1/batch",
        json={
            "tokens": [
                "0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913",
                "0x4200000000000000000000000000000000000006",
            ],
        },
    )
    print(res.status_code, res.text)