Render a candlestick from kline - Archer Exchange

kline streams OHLCV bars off the last-traded-price. Kline uses its own subscribe_kline op with a resolution (only one resolution per market per connection — re-subscribing replaces it).

{ "op": "subscribe_kline", "resolution": "1", "market": "5Ggx..." }

Valid resolutions: "1", "5", "15", "30", "60", "240" (minutes), "D", "W", "M". Anything else → INVALID_RESOLUTION.

Step 2 - seed with the current-bar snapshot (`type: "snapshot"`).

Step 3 - update the live bar

Every type: "update" carries the current bar. The bar’s time is unix-seconds (not ms) of the bar open. A new bar is signaled implicitly: when an update arrives with a time greater than your current bar’s time, the previous bar has closed, commit it and start the new one. There is no explicit “bar closed” message.

let bars = [];        // committed, closed bars

let live = null;      // the currently open bar

function onKline(msg) {

  const bar = msg.data; // { time, open, high, low, close, volume } — all strings except time

  if (!live || bar.time > live.time) {

    if (live) bars.push(live);   // previous bar closed → commit it

    live = bar;

  } else {

    live = bar;                  // same bar, updated OHLCV

  }

}

Historical bars come from REST GET /v1/klines), not the stream — the WS kline channel only carries the current open bar and its updates. Load history via REST, then attach the stream for the live bar. mid_kline is identical but built from the book mid (best_bid + best_ask) / 2) instead of trade prints, use subscribe_mid_kline and switch on msg.ch === "mid_kline". The two are independent streams; subscribe to whichever (or both) you need.