Validate

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://api.babyblueviper.com/validate' \
  -H 'content-type: application/json' \
  --data-raw '{"n_trials":1,"returns":[0.012,-0.004,0.018,0,-0.007,0.011,0.005,-0.002,0.009,0.014]}'

# 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.babyblueviper.com/validate' \
  -H 'content-type: application/json' \
  --data-raw '{"n_trials":1,"returns":[0.012,-0.004,0.018,0,-0.007,0.011,0.005,-0.002,0.009,0.014]}' \
  | 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 $0.2475 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.2475" });
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 $0.2475 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fapi.babyblueviper.com%2Fvalidate&method=POST
const res = await pay("https://api.babyblueviper.com/validate", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "n_trials": 1,
    "returns": [
      0.012,
      -0.004,
      0.018,
      0,
      -0.007,
      0.011,
      0.005,
      -0.002,
      0.009,
      0.014
    ]
  }),
});
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 $0.2475 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.2475"})
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.babyblueviper.com/validate",
        json={
            "n_trials": 1,
            "returns": [
                0.012,
                -0.004,
                0.018,
                0,
                -0.007,
                0.011,
                0.005,
                -0.002,
                0.009,
                0.014,
            ],
        },
    )
    print(res.status_code, res.text)