curl "https://api.aioka.io/v1/signals/history?signal_key=FEAR_GREED_INDEX&per_page=48" \
  -H "X-API-Key: aik_pro_your_key_here"

{
  "items": [
    {
      "recorded_at": "2026-04-03T10:00:00Z",
      "signal_key": "FEAR_GREED_INDEX",
      "display_name": "Fear & Greed Index",
      "value": 38.0
    }
  ],
  "total": 720,
  "page": 1,
  "per_page": 48,
  "cached": false,
  "cache_ttl_seconds": 300
}