Legacy Live X402 Payment Preflight

{
  "data": {
    "chargedAmount": "10059",
    "inputHash": "sha256:33b296d1a53e712c7080b64368e56b237fc8c1ac3d3e0a28284a9f166…",
    "limitations": [
      "Public or synthetic nonpersonal input only; caller labels are no…"
    ],
    "productId": "live-x402-payment-preflight",
    "result": {
      "allRequiredQuotesValid": true,
      "deliveryTested": false,
      "observation": {
        "challengeDigest": "sha256:743af9b98c837bd1dd33327595b2eba4a3323c0ab8e5186bdb5218a03…",
        "challengeState": "observed",
        "durationMs": 20,
        "networks": [
          {
            "amountBaseUnits": "1000",
            "network": "eip155:8453",
            "reasons": [],
            "state": "valid_quote"
          }
        ],
        "observedAt": "2026-10-12T12:00:00.000Z",
        "resource": "https://www.mahastrategies.com/api/v1/compress",
        "responseStatus": 402,
        "schemaDigest": "sha256:996dfe72b52d6610106b64cf47bc4d22123c1dc8370a91608cc3b699f…",
        "schemaState": "present_not_validated"
      },
      "paymentsMade": 0
    },
    "resultHash": "sha256:1197ea4138a6d0ed889c1333b75f15ad14ba59ed1d9a6c811f8c654c9…",
    "version": "maha-reviewed-legacy-port/1"
  },
  "proof": {
    "settlement_id": "0x00000000000000000000000000000000000000000000000000000000000000…"
  },
  "success": true
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://www.mahastrategies.com/api/v1/verify/legacy/live-x402-payment-preflight' \
  -H 'content-type: application/json' \
  --data-raw '{"dataClass":"synthetic","nonpersonalMetadata":true,"request":{"dataClass":"synthetic","expectedPayee":"0xec84c1cd6602bbe387bc8e6f0d3c062f2762de28","maximumAmountBaseUnits":"2000","requiredNetworks":["eip155:8453","eip155:42161"],"resource":"https://www.mahastrategies.com/api/v1/compress"}}'

# 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://www.mahastrategies.com/api/v1/verify/legacy/live-x402-payment-preflight' \
  -H 'content-type: application/json' \
  --data-raw '{"dataClass":"synthetic","nonpersonalMetadata":true,"request":{"dataClass":"synthetic","expectedPayee":"0xec84c1cd6602bbe387bc8e6f0d3c062f2762de28","maximumAmountBaseUnits":"2000","requiredNetworks":["eip155:8453","eip155:42161"],"resource":"https://www.mahastrategies.com/api/v1/compress"}}' \
  | 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 $0.010059 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.010059" });
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 $0.010059 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fwww.mahastrategies.com%2Fapi%2Fv1%2Fverify%2Flegacy%2Flive-x402-payment-preflight&method=POST
const res = await pay("https://www.mahastrategies.com/api/v1/verify/legacy/live-x402-payment-preflight", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "dataClass": "synthetic",
    "nonpersonalMetadata": true,
    "request": {
      "dataClass": "synthetic",
      "expectedPayee": "0xec84c1cd6602bbe387bc8e6f0d3c062f2762de28",
      "maximumAmountBaseUnits": "2000",
      "requiredNetworks": [
        "eip155:8453",
        "eip155:42161"
      ],
      "resource": "https://www.mahastrategies.com/api/v1/compress"
    }
  }),
});
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 $0.010059 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.010059"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.post(
        "https://www.mahastrategies.com/api/v1/verify/legacy/live-x402-payment-preflight",
        json={
            "dataClass": "synthetic",
            "nonpersonalMetadata": True,
            "request": {
                "dataClass": "synthetic",
                "expectedPayee": "0xec84c1cd6602bbe387bc8e6f0d3c062f2762de28",
                "maximumAmountBaseUnits": "2000",
                "requiredNetworks": [
                    "eip155:8453",
                    "eip155:42161",
                ],
                "resource": "https://www.mahastrategies.com/api/v1/compress",
            },
        },
    )
    print(res.status_code, res.text)