Bitcoin Address

{
  "address": "bc1qxy2kgdygjrsqtzq2n0yrf2493p83kkfjhx0wlh",
  "balance": {
    "btc": 3.92247777,
    "sats": 392247777,
    "usd": 331494.8
  },
  "btc_price_usd": 84511.58149319161,
  "last": [
    {
      "confirmations": 644,
      "confirmed": true,
      "date": "2026-09-28T12:34:10+00:00",
      "fee_sats": 680,
      "net_btc": 0.00000546,
      "txid": "5420695c11ddebff09fd2786c16b8481b2187cb750458880ddd9e71cbf0da0e8"
    },
    {
      "confirmations": 2487,
      "confirmed": true,
      "date": "2026-09-15T16:26:34+00:00",
      "fee_sats": 10000,
      "net_btc": 0.03025698,
      "txid": "9b46bfde6702335f68f6a78eaf7cab35875598c9584e95f0e3442f3b1e82aa82"
    }
  ],
  "mempool_pending": {
    "btc": 0,
    "sats": 0
  },
  "source": "Blockstream Esplora (public Bitcoin node)",
  "total_received_btc": 16.79253616,
  "total_sent_btc": 12.87005839,
  "transactions": 1138,
  "type": "segwit"
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://api.vextorium.com/v1/bitcoin-address' \
  -H 'content-type: application/json' \
  --data-raw '{"address":"bc1qxy2kgdygjrsqtzq2n0yrf2493p83kkfjhx0wlh","limit":3}'

# 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.vextorium.com/v1/bitcoin-address' \
  -H 'content-type: application/json' \
  --data-raw '{"address":"bc1qxy2kgdygjrsqtzq2n0yrf2493p83kkfjhx0wlh","limit":3}' \
  | 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 $0.004 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.004" });
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 $0.004 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fapi.vextorium.com%2Fv1%2Fbitcoin-address&method=POST
const res = await pay("https://api.vextorium.com/v1/bitcoin-address", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "address": "bc1qxy2kgdygjrsqtzq2n0yrf2493p83kkfjhx0wlh",
    "limit": 3
  }),
});
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 $0.004 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.004"})
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.vextorium.com/v1/bitcoin-address",
        json={
            "address": "bc1qxy2kgdygjrsqtzq2n0yrf2493p83kkfjhx0wlh",
            "limit": 3,
        },
    )
    print(res.status_code, res.text)