Run analytical SQL on local CSV/Parquet files via mcp-server-duckdb (uvx)

{
  "server": "mcp-duckdb-server v1.27.2",
  "launch": "uvx mcp-server-duckdb --db-path /tmp/pathfinder_test.duckdb",
  "transport": "stdio (NDJSON)",
  "protocol": "2024-11-05",
  "tools": [
    {
      "name": "query",
      "params": {
        "query": "string (required)"
      }
    }
  ],
  "trace": {
    "initialize": {
      "recv": {
        "serverInfo": {
          "name": "mcp-duckdb-server",
          "version": "1.27.2"
        },
        "protocolVersion": "2024-11-05"
      }
    },
    "tools_list": {
      "recv_tools": ["query"]
    },
    "query_1_aggregate": {
      "send": {
        "method": "tools/call",
        "params": {
          "name": "query",
          "arguments": {
            "query": "SELECT product, SUM(revenue) as total_revenue, SUM(units_sold) as total_units, ROUND(AVG(revenue::FLOAT/units_sold), 2) as avg_price FROM read_csv_auto('/tmp/pathfinder_test_sales.csv') GROUP BY product ORDER BY total_revenue DESC"
          }
        }
      },
      "recv": {
        "content": [
          {
            "type": "text",
            "text": "[('Widget B', 55400, 1108, 50.0), ('Widget A', 45900, 918, 50.0)]"
          }
        ],
        "isError": false
      },
      "latency_ms": 68
    },
    "query_2_window_function": {
      "send": {
        "method": "tools/call",
        "params": {
          "name": "query",
          "arguments": {
            "query": "SELECT product, region, quarter, revenue, SUM(revenue) OVER (PARTITION BY product ORDER BY quarter) as running_total FROM read_csv_auto('/tmp/pathfinder_test_sales.csv') ORDER BY product, quarter, region"
          }
        }
      },
      "recv": {
        "content": [
          {
            "type": "text",
            "text": "[('Widget A', 'North', 'Q1', 12500, 22300), ('Widget A', 'South', 'Q1', 9800, 22300), ('Widget A', 'North', 'Q2', 13100, 45900), ('Widget A', 'South', 'Q2', 10500, 45900), ('Widget B', 'North', 'Q1', 15200, 26500), ('Widget B', 'South', 'Q1', 11300, 26500), ('Widget B', 'North', 'Q2', 16800, 55400), ('Widget B', 'South', 'Q2', 12100, 55400)]"
          }
        ],
        "isError": false
      },
      "latency_ms": 21
    }
  },
  "gotchas": ["param is 'query' not 'sql'", "--db-path required on launch", "results are Python tuple strings", "use ::FLOAT for float division"]
}