Asset data best practices

const BASE_URL = 'https://api.services.payward.com';

async function listAllAssets(country, quoteSymbol = 'USD') {
  const assets = [];
  let pageToken;
  do {
    const params = new URLSearchParams({ country, quote_symbol: quoteSymbol, page_size: '100' });
    if (pageToken) params.set('page_token', pageToken);

    const response = await fetch(`${BASE_URL}/v1/assets?${params}`);
    if (!response.ok) throw new Error(`List assets failed: ${response.status}`);
    const page = await response.json();

    assets.push(...page.data);
    pageToken = page.next_page_token;
  } while (pageToken);
  return assets;
}

const catalog = await listAllAssets('DE', 'EUR');

import requests

BASE_URL = "https://api.services.payward.com"


def list_all_assets(country, quote_symbol="USD"):
    assets = []
    page_token = None
    while True:
        params = {"country": country, "quote_symbol": quote_symbol, "page_size": 100}
        if page_token:
            params["page_token"] = page_token

        response = requests.get(f"{BASE_URL}/v1/assets", params=params, timeout=10)
        response.raise_for_status()
        page = response.json()

        assets.extend(page["data"])
        page_token = page.get("next_page_token")
        if not page_token:
            return assets


catalog = list_all_assets("DE", "EUR")

from datetime import datetime, timedelta, timezone

import requests

BASE_URL = "https://api.services.payward.com"


def fetch_all_pages(path, params):
    rows, page_token = [], None
    while True:
        query = params + ([("page_token", page_token)] if page_token else [])
        response = requests.get(f"{BASE_URL}{path}", params=query, timeout=10)
        response.raise_for_status()
        body = response.json()
        rows.extend(body["data"])
        page_token = body.get("next_page_token")  # Absent on the last page, even if `data` is empty.
        if not page_token:
            return rows


def parse(timestamp):
    return datetime.fromisoformat(timestamp.replace("Z", "+00:00"))


def refresh_candles(held, asset_type, asset_symbol):
    now = datetime.now(timezone.utc)
    start = held[-1]["timestamp"] if held else (now - timedelta(days=14)).isoformat()
    fresh = fetch_all_pages(
        f"/v1/assets/{asset_type}/{asset_symbol}/rates",
        [
            ("country", "US"),
            ("interval", "PT60M"),
            ("start_timestamp", start),  # Inclusive: re-fetches the newest candle.
            ("end_timestamp", now.isoformat()),
        ],
    )
    cutoff = parse(fresh[0]["timestamp"]) if fresh else datetime.max.replace(tzinfo=timezone.utc)
    return [c for c in held if parse(c["timestamp"]) < cutoff] + fresh


candles = refresh_candles([], "crypto", "BTC")  # First load: 14 days.
candles = refresh_candles(candles, "crypto", "BTC")  # Later: one small request.

const BASE_URL = 'https://api.services.payward.com';

async function fetchAllPages(path, params) {
  const rows = [];
  let pageToken;
  do {
    const query = new URLSearchParams(params);
    if (pageToken) query.set('page_token', pageToken);
    const response = await fetch(`${BASE_URL}${path}?${query}`);
    if (!response.ok) throw new Error(`HTTP ${response.status}`);
    const body = await response.json();
    rows.push(...body.data);
    pageToken = body.next_page_token; // Absent on the last page, even if `data` is empty.
  } while (pageToken);
  return rows;
}

async function refreshCandles(held, assetType, assetSymbol) {
  const twoWeeksAgo = new Date(Date.now() - 14 * 24 * 3600 * 1000).toISOString();
  const fresh = await fetchAllPages(`/v1/assets/${assetType}/${assetSymbol}/rates`, [
    ['country', 'US'],
    ['interval', 'PT60M'],
    ['start_timestamp', held.at(-1)?.timestamp ?? twoWeeksAgo], // Inclusive: re-fetches the newest candle.
    ['end_timestamp', new Date().toISOString()],
  ]);
  const cutoff = fresh.length ? Date.parse(fresh[0].timestamp) : Infinity;
  return [...held.filter(candle => Date.parse(candle.timestamp) < cutoff), ...fresh];
}

let candles = await refreshCandles([], 'crypto', 'BTC'); // First load: 14 days.
candles = await refreshCandles(candles, 'crypto', 'BTC'); // Later: one small request.

// Assumes the asset has a price. See "Handle missing fields".
function toEmbedShape(asset) {
  const price = Number(asset.price);
  const percent = Number(asset.price_change_percent?.last_24h);
  return {
    symbol: asset.symbol,
    english_name: asset.name,
    description: asset.description,
    circulating_supply: asset.supply?.circulating,
    total_supply: asset.supply?.total,
    max_supply: asset.supply?.max,
    market_cap_value: asset.market_cap,
    dominance_percent: asset.market_dominance,
    market_cap_rank: asset.market_cap_rank,
    // Approximate: last_24h is rounded to two decimals.
    change_value_24h: String(price - price / (1 + percent / 100)),
    change_percent_24h: asset.price_change_percent?.last_24h,
    volume_value_24h: asset.volume?.last_24h,
    ath_value: asset.ath?.value,
    ath_date: asset.ath?.timestamp?.slice(0, 10),
    links: { logo: asset.logo },
  };
}

from decimal import Decimal


# Assumes the asset has a price. See "Handle missing fields".
def to_embed_shape(asset):
    price = Decimal(asset["price"])
    percent = Decimal(asset["price_change_percent"]["last_24h"])
    return {
        "symbol": asset["symbol"],
        "english_name": asset["name"],
        "description": asset.get("description"),
        "circulating_supply": asset.get("supply", {}).get("circulating"),
        "total_supply": asset.get("supply", {}).get("total"),
        "max_supply": asset.get("supply", {}).get("max"),
        "market_cap_value": asset.get("market_cap"),
        "dominance_percent": asset.get("market_dominance"),
        "market_cap_rank": asset.get("market_cap_rank"),
        # Approximate: last_24h is rounded to two decimals.
        "change_value_24h": str(price - price / (1 + percent / 100)),
        "change_percent_24h": asset["price_change_percent"]["last_24h"],
        "volume_value_24h": asset.get("volume", {}).get("last_24h"),
        "ath_value": asset.get("ath", {}).get("value"),
        "ath_date": asset.get("ath", {}).get("timestamp", "")[:10] or None,
        "links": {"logo": asset["logo"]},
    }