What this source is
Coinbase Exchange's public market data, relayed unread. No key is asked for because none is needed — these paths are open, and nothing here can reach an account. A candle row is `[time, low, high, open, close, volume]`: low and high come before open and close, which is not the order most vendors use, and rows arrive newest first. Buckets start at 00:00 UTC and a 24-hour market has no close, so which bucket counts as finished is the caller's convention to state. At most 300 candles answer one call. `ticker`, `stats`, `book` and `trades` take no date and are always now.
