Returns aggregated volume and buy-pressure metrics for a (provider, contract_id) over a trailing window, computed from the same deduplicated trade data as /v1/trades.

Two query shapes depending on provider, because the platform cannot generically infer which side of a market is "Yes":

• Kalshi: outcome_0 is the side where outcome or token_id (case-insensitive) equals "yes", outcome_1 is "no".
• All other providers: volumes are grouped by token_id and the top 2 tokens by volume are reported as outcome_0/outcome_1 — a volume ranking, not a guaranteed Yes/No mapping.

USD volume is always size * price / 100 (price is cents 0–100 for every provider). outcome_0_volume_share_pct defaults to 50.0 when both outcome volumes are zero. coverage_pct measures how much of the requested window is actually backed by data and is 0 when no trades are found in the window.

Rate-limit cost (LIGHT bucket): flat 1 unit per request.

Caching: responses are cached for 10s per replica (with singleflight coalescing) to absorb duplicate concurrent requests. Cache-Control: private, max-age=5, no ETag — this route never returns 304.

{
  "metrics": {
    "volume_usd": 184032.55,
    "outcome_0_volume_usd": 121004.1,
    "outcome_1_volume_usd": 63028.45,
    "outcome_0_volume_share_pct": 65.8,
    "trade_count": 5123,
    "window_seconds": 3600,
    "coverage_pct": 97.2
  }
}