The Volcanic Engine Concept Pack

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://www.mahastrategies.com/api/v1/library/the-volcanic-engine/concept-pack' \
  -H 'content-type: application/json' \
  --data-raw '{"concepts":[{"id":"declared-topic","label":"Declared reading topic","referenceIds":["volcano"]}],"dataClass":"synthetic","units":[{"bookId":"the-volcanic-engine","editionDigest":"sha256:04f33b4b1659e0b4a68213e47ee48b3fda05e20f3863bba42af6442c58e18285","referenceId":"volcano","sectionId":"unit-002-part-1"}]}'

# 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/library/the-volcanic-engine/concept-pack' \
  -H 'content-type: application/json' \
  --data-raw '{"concepts":[{"id":"declared-topic","label":"Declared reading topic","referenceIds":["volcano"]}],"dataClass":"synthetic","units":[{"bookId":"the-volcanic-engine","editionDigest":"sha256:04f33b4b1659e0b4a68213e47ee48b3fda05e20f3863bba42af6442c58e18285","referenceId":"volcano","sectionId":"unit-002-part-1"}]}' \
  | 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 $0.010035 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.010035" });
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 $0.010035 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fwww.mahastrategies.com%2Fapi%2Fv1%2Flibrary%2Fthe-volcanic-engine%2Fconcept-pack&method=POST
const res = await pay("https://www.mahastrategies.com/api/v1/library/the-volcanic-engine/concept-pack", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "concepts": [
      {
        "id": "declared-topic",
        "label": "Declared reading topic",
        "referenceIds": [
          "volcano"
        ]
      }
    ],
    "dataClass": "synthetic",
    "units": [
      {
        "bookId": "the-volcanic-engine",
        "editionDigest": "sha256:04f33b4b1659e0b4a68213e47ee48b3fda05e20f3863bba42af6442c58e18285",
        "referenceId": "volcano",
        "sectionId": "unit-002-part-1"
      }
    ]
  }),
});
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 $0.010035 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.010035"})
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/library/the-volcanic-engine/concept-pack",
        json={
            "concepts": [
                {
                    "id": "declared-topic",
                    "label": "Declared reading topic",
                    "referenceIds": [
                        "volcano",
                    ],
                },
            ],
            "dataClass": "synthetic",
            "units": [
                {
                    "bookId": "the-volcanic-engine",
                    "editionDigest": "sha256:04f33b4b1659e0b4a68213e47ee48b3fda05e20f3863bba42af6442c58e18285",
                    "referenceId": "volcano",
                    "sectionId": "unit-002-part-1",
                },
            ],
        },
    )
    print(res.status_code, res.text)