Reads over HTTP

// npm install @noble/ed25519 bs58   (Node 18 or later, for fetch)
import * as ed from '@noble/ed25519';
import bs58 from 'bs58';

const BASE_URL = 'https://partners-rt-gw.sandbox.securitize.io';
const privateKey = bs58.decode(process.env.CET_SIGNING_KEY).slice(0, 32);
const publicKey = bs58.encode(await ed.getPublicKeyAsync(privateKey));

async function signedGet(path, params = {}) {
  // Encoded once: the same string is signed and sent.
  const query = new URLSearchParams(params).toString();
  const target = query ? `${path}?${query}` : path;
  const timestamp = Math.floor(Date.now() / 1000);
  const signed = new TextEncoder().encode(`${timestamp}.GET.${target}`);
  const signature = bs58.encode(await ed.signAsync(signed, privateKey));

  const response = await fetch(BASE_URL + target, {
    headers: { 'x-public-key': publicKey, 'x-timestamp': String(timestamp), 'x-signature': signature },
  });
  return { status: response.status, body: await response.json() };
}

console.log(await signedGet('/v1/market-maker/redemption-balance', { symbol: 'AAPL', chainId: 196 }));

# pip install requests pynacl base58
import os, time
from urllib.parse import urlencode

import base58
import requests
from nacl.signing import SigningKey

BASE_URL = "https://partners-rt-gw.sandbox.securitize.io"
signing_key = SigningKey(base58.b58decode(os.environ["CET_SIGNING_KEY"])[:32])
public_key = base58.b58encode(bytes(signing_key.verify_key)).decode()


def signed_get(path, params=None):
    query = urlencode(params or {})  # encoded once: the same string is signed and sent
    target = f"{path}?{query}" if query else path
    timestamp = int(time.time())
    signature = base58.b58encode(signing_key.sign(f"{timestamp}.GET.{target}".encode()).signature).decode()
    response = requests.get(
        BASE_URL + target,
        headers={"x-public-key": public_key, "x-timestamp": str(timestamp), "x-signature": signature},
    )
    return response.status_code, response.json()


print(signed_get("/v1/market-maker/redemption-balance", {"symbol": "AAPL", "chainId": 196}))