Build a Trading Terminal

const API = 'https://api.serialized.xyz/v1';
const KEY = process.env.SERIALIZED_API_KEY!;

export async function sd<T>(
  path: string,
  params: Record<string, string | number | boolean | undefined> = {},
): Promise<{ data: T; meta: Record<string, any> }> {
  const qs = new URLSearchParams();
  for (const [k, v] of Object.entries(params)) if (v !== undefined) qs.set(k, String(v));
  const res = await fetch(`${API}${path}?${qs}`, { headers: { Authorization: KEY } });
  if (!res.ok) {
    const { error } = await res.json();
    throw new Error(`${res.status} ${error.code}: ${error.message}`);
  }
  return res.json();
}

type View = 'new' | 'bonding' | 'graduated';

const column = (view: View) =>
  sd<PulseCard[]>('/pulse', { view, chains: 'evm:8453,solana' });

async function refreshDiscovery() {
  const [fresh, bonding, graduated] = await Promise.all([
    column('new'), column('bonding'), column('graduated'),
  ]);
  render({ fresh: fresh.data, bonding: bonding.data, graduated: graduated.data });
}

setInterval(refreshDiscovery, 3_000);

const [token, stats] = await Promise.all([
  sd<Token>('/token', { chain, address }),
  sd<TokenStats>('/token/stats', { chain, address, windows: '5m,1h,4h,6h,24h' }),
]);

async function getBars(chain: string, address: string, interval: string,
                       { to, countBack, firstDataRequest }: PeriodParams) {
  const { data, meta } = await sd<Candle[]>('/token/ohlcv', {
    chain, address, interval,
    endTime: firstDataRequest ? undefined : to,   // unix seconds
    limit: Math.min(countBack || 500, 2000),
  });
  return {
    bars: data.map(c => ({ time: c.time * 1000, open: c.open, high: c.high,
                           low: c.low, close: c.close, volume: c.volumeToken })),
    meta: { noData: data.length === 0 && !meta.hasMore },
  };
}

const ws = new WebSocket('wss://api.serialized.xyz/v1/stream');
const sub = (channel: string, id: string, params: object) =>
  ws.send(JSON.stringify({ op: 'subscribe', channel, id, params }));

ws.onopen = () => ws.send(JSON.stringify({ op: 'auth', apiKey: KEY }));

ws.onmessage = (m) => {
  const frame = JSON.parse(m.data as string);
  if (frame.op === 'auth.ok') {
    setInterval(() => ws.send(JSON.stringify({ op: 'ping' })), 30_000);
    sub('trades', 'tape', { chain, address });          // every trade, as it lands
    sub('token-updates', 'header', { chain, address }); // price/mcap/stats24h, ≤1/s
  }
  if (frame.op === 'event' && frame.id === 'tape') prependTrade(frame.data);
  if (frame.op === 'event' && frame.id === 'header') patchHeader(frame.data);
};