Response contract - Meridian

Futures and spot

Futures and spot methods return this top-level shape:

{
  "schema_version": "2.0",
  "surface": "futures",
  "request_id": "...",
  "rows": [],
  "columns": [],
  "coverage": [],
  "provenance": [],
  "warnings": [],
  "next_cursor": null
}

Custom bars

Custom bars add explicit completion fields:

{
  "schema_version": "custom_trade_bars_v1",
  "surface": "custom-bars",
  "request_id": "...",
  "query_complete": true,
  "data_gap": false,
  "retry_recommended": false,
  "alternative_query_required": false,
  "completion_reason": "stored_fact_query_completed",
  "result_status": "available",
  "no_results_reason": null,
  "canonical_request": {},
  "rows": [],
  "columns": [],
  "coverage": [],
  "provenance": [],
  "warnings": [],
  "next_cursor": null
}

Interpretation rules

rows contains DataFrame-ready records.
columns describes types, units, families, and aggregation rules.
coverage reports availability for requested identities and intervals.
provenance explains where stored facts originated.
warnings must be retained when displaying or transforming results.
next_cursor is present only when another explicit page exists.

Missing values remain null. A warning or source-limited coverage segment explains known limitations; it does not authorize imputation.