curl -X GET "https://api.adrelay.dev/v1/usage-logs" \
  -H "X-API-Key: $ADRELAY_API_KEY"

{
  "usage_logs": [
    {
      "id": "log_abc123",
      "method": "GET",
      "path": "/v1/campaigns",
      "status_code": 200,
      "timestamp": "2026-03-21T09:45:00Z",
      "response_time_ms": 120
    },
    {
      "id": "log_def456",
      "method": "POST",
      "path": "/v1/campaigns",
      "status_code": 201,
      "timestamp": "2026-03-21T09:30:00Z",
      "response_time_ms": 850
    }
  ],
  "pagination": {
    "next_cursor": "eyJpZCI6ImxvZ19kZWY0NTYifQ==",
    "has_more": true
  }
}