Fx

{
  "briefing_metadata": {
    "correlations_count": 4,
    "description": "Dollar and currency environment - EUR/USD, USD/CNY direction with net liquidity correlation",
    "metrics_count": 5,
    "name": "FX Liquidity"
  },
  "briefing_used": "fx.liquidity",
  "metrics": {
    "bitcoin-price": {
      "name": "bitcoin-price"
    },
    "cny-usd": {
      "name": "cny-usd"
    },
    "dxy": {
      "name": "dxy"
    },
    "eur-usd": {
      "name": "eur-usd"
    },
    "net-liquidity": {
      "name": "net-liquidity"
    }
  }
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://api.prereason.com/api/fx?format=json'

# 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://api.prereason.com/api/fx?format=json' \
  | 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 $0.05 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.05" });
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 $0.05 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fapi.prereason.com%2Fapi%2Ffx
const res = await pay("https://api.prereason.com/api/fx?format=json");
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 $0.05 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.05"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://api.prereason.com/api/fx?format=json")
    print(res.status_code, res.text)