Holdcheck

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://svm402.com/holdcheck/:solana_address?liquidity_usd=611119'

# 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://svm402.com/holdcheck/:solana_address?liquidity_usd=611119' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode

// npm i @x402/fetch @x402/svm @solana/kit @scure/base
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactSvmScheme } from "@x402/svm/exact/client";
import { createKeyPairSignerFromBytes } from "@solana/kit";
import { base58 } from "@scure/base";

// Pays at most $0.01 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.01" });
registerExactSvmScheme(client, { signer: await createKeyPairSignerFromBytes(base58.decode(process.env.SVM_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 $0.01 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fsvm402.com%2Fholdcheck%2F%3Asolana_address
const res = await pay("https://svm402.com/holdcheck/:solana_address?liquidity_usd=611119");
console.log(res.status, await res.text());

# pip install "x402[requests,svm]"
import os
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.svm import KeypairSigner
from x402.mechanisms.svm.exact.register import register_exact_svm_client

# Pays at most $0.01 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.01"})
register_exact_svm_client(client, KeypairSigner.from_base58(os.environ["SVM_PRIVATE_KEY"]))

with x402_requests(client) as session:
    res = session.get("https://svm402.com/holdcheck/:solana_address?liquidity_usd=611119")
    print(res.status_code, res.text)