GET /api/v1/indices/{index_id}/history
The immutable stored tick series behind the charts, served as OHLC buckets over the requested window: range is 1d, 1w, 1m, 6m, 1y or all (default 1m); resolution is auto (the default) or an explicit bucket size — a combination finer than the range supports is a 400 unsupported-history-resolution problem.
Every response discloses its own coverage via
meta.availability and
meta.coverage — a short series never reads as a quiet market.