Scholarly Search

{
  "jobs": [
    {
      "authors": [
        "Merlinda Andoni",
        "Valentin Robu"
      ],
      "citations": 2447,
      "doi": "https://doi.org/10.1016/j.rser.2018.10.014",
      "id": "https://openalex.org/W2899357412",
      "institutions": [
        "Durham University",
        "Heriot-Watt University"
      ],
      "journal": "Renewable and Sustainable Energy Reviews",
      "open_access": "https://www.sciencedirect.com/science/article/pii/S1364032118307184/pdf",
      "title": "Blockchain technology in the energy sector: A systematic review of challenges and opportunities",
      "type": "review",
      "year": 2018
    },
    {
      "authors": [
        "David Yermack"
      ],
      "citations": 1030,
      "doi": "https://doi.org/10.1093/rof/rfw074",
      "id": "https://openalex.org/W3123597155",
      "institutions": [
        "Cardiff University",
        "Concordia University"
      ],
      "journal": "European Finance Review",
      "open_access": null,
      "title": "Corporate Governance and Blockchains",
      "type": "article",
      "year": 2016
    }
  ],
  "search": "agent payments blockchain",
  "source": "OpenAlex (CC0)",
  "total": 26170
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i -X POST 'https://api.vextorium.com/v1/scholarly-search' \
  -H 'content-type: application/json' \
  --data-raw '{"limit":2,"search":"agent payments blockchain"}'

# 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/scholarly-search' \
  -H 'content-type: application/json' \
  --data-raw '{"limit":2,"search":"agent payments blockchain"}' \
  | 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 $0.003 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.003" });
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 $0.003 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fapi.vextorium.com%2Fv1%2Fscholarly-search&method=POST
const res = await pay("https://api.vextorium.com/v1/scholarly-search", {
  method: "POST",
  headers: { "content-type": "application/json" },
  body: JSON.stringify({
    "limit": 2,
    "search": "agent payments blockchain"
  }),
});
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 $0.003 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.003"})
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/scholarly-search",
        json={
            "limit": 2,
            "search": "agent payments blockchain",
        },
    )
    print(res.status_code, res.text)