{
  "postgres": "17.4",
  "visible_columns": [
    {
      "table": "docs.pages",
      "column": "slug",
      "type": "text"
    },
    {
      "table": "docs.pages",
      "column": "editor_id",
      "type": "text"
    },
    {
      "table": "docs.pages",
      "column": "section",
      "type": "text"
    },
    {
      "table": "docs.pages",
      "column": "words",
      "type": "integer"
    }
  ],
  "write_problems": [],
  "queries": {
    "first five pages": {
      "sql": "SELECT slug, section, words FROM docs.pages ORDER BY slug",
      "max_rows": 5,
      "result": {
        "columns": [
          "slug",
          "section",
          "words"
        ],
        "rows": [
          [
            "page-01",
            "reference",
            225
          ],
          [
            "page-02",
            "changelog",
            250
          ],
          [
            "page-03",
            "guides",
            275
          ],
          [
            "page-04",
            "reference",
            300
          ],
          [
            "page-05",
            "changelog",
            325
          ]
        ],
        "truncated": true
      }
    },
    "pages per section": {
      "sql": "SELECT section, count(*) AS pages FROM docs.pages GROUP BY section ORDER BY section",
      "max_rows": 50,
      "result": {
        "columns": [
          "section",
          "pages"
        ],
        "rows": [
          [
            "changelog",
            10
          ],
          [
            "guides",
            10
          ],
          [
            "reference",
            10
          ]
        ],
        "truncated": false
      }
    },
    "one row of a million": {
      "sql": "SELECT n FROM generate_series(1, 1000000) AS n",
      "max_rows": 1,
      "result": {
        "columns": [
          "n"
        ],
        "rows": [
          [
            1
          ]
        ],
        "truncated": true
      }
    },
    "insert a page": {
      "sql": "INSERT INTO docs.pages VALUES ('page-99', 'e-1', 'guides', 100)",
      "max_rows": 50,
      "rejected": "only one SELECT or VALUES query is allowed",
      "sqlstate": "42601"
    },
    "delete inside WITH": {
      "sql": "WITH gone AS (DELETE FROM docs.pages RETURNING slug) SELECT * FROM gone",
      "max_rows": 50,
      "rejected": "the query uses a feature a cursor does not allow, such as a data-modifying WITH",
      "sqlstate": "0A000"
    },
    "function that writes": {
      "sql": "SELECT lo_create(0)",
      "max_rows": 50,
      "rejected": "the transaction is read-only",
      "sqlstate": "25006"
    },
    "read editor emails": {
      "sql": "SELECT email FROM docs.editors",
      "max_rows": 50,
      "rejected": "the role lacks the privilege",
      "sqlstate": "42501"
    },
    "slow query": {
      "sql": "SELECT pg_sleep(2)",
      "max_rows": 50,
      "rejected": "the query ran longer than 500 ms",
      "sqlstate": "57014"
    },
    "two statements": {
      "sql": "SELECT 1; SELECT 2",
      "max_rows": 50,
      "rejected": "only one SELECT or VALUES query is allowed",
      "sqlstate": "42601"
    },
    "turn off read-only for the session": {
      "sql": "SELECT set_config('default_transaction_read_only', 'off', false)",
      "max_rows": 50,
      "result": {
        "columns": [
          "set_config"
        ],
        "rows": [
          [
            "off"
          ]
        ],
        "truncated": false
      }
    },
    "function that writes, next call": {
      "sql": "SELECT lo_create(0)",
      "max_rows": 50,
      "rejected": "the transaction is read-only",
      "sqlstate": "25006"
    },
    "one 300,000-character value": {
      "sql": "SELECT repeat('x', 300000) AS big",
      "max_rows": 1,
      "rejected": "the result is larger than 200000 bytes; select fewer or shorter values",
      "sqlstate": null
    },
    "send a notification": {
      "sql": "SELECT pg_notify('docs', 'hello')",
      "max_rows": 50,
      "result": {
        "columns": [
          "pg_notify"
        ],
        "rows": [
          [
            ""
          ]
        ],
        "truncated": false
      }
    },
    "too many rows requested": {
      "sql": "SELECT slug FROM docs.pages",
      "max_rows": 1000,
      "rejected": "max_rows must be an integer from 1 to 200",
      "sqlstate": null
    }
  },
  "role_checks": {
    "read-only default after SET": "off",
    "insert with read-only off": "42501: permission denied for table pages",
    "delete with read-only off": "42501: permission denied for table pages",
    "read editors with read-only off": "42501: permission denied for table editors",
    "create a large object with read-only off": "allowed"
  },
  "mcp": {
    "tool": {
      "name": "run_query",
      "title": "Run a read-only SQL query",
      "description": "Run one SELECT or VALUES query on the docs database. Returns at most max_rows rows (200 at most) and 200,000 bytes; each query stops after 500 ms.",
      "inputSchema": {
        "type": "object",
        "properties": {
          "sql": {
            "maxLength": 10000,
            "minLength": 1,
            "title": "Sql",
            "type": "string"
          },
          "max_rows": {
            "default": 50,
            "maximum": 200,
            "minimum": 1,
            "title": "Max Rows",
            "type": "integer"
          }
        },
        "required": [
          "sql"
        ],
        "title": "run_queryArguments"
      },
      "outputSchema": {
        "properties": {
          "columns": {
            "items": {
              "type": "string"
            },
            "title": "Columns",
            "type": "array"
          },
          "rows": {
            "items": {
              "items": {},
              "type": "array"
            },
            "title": "Rows",
            "type": "array"
          },
          "truncated": {
            "title": "Truncated",
            "type": "boolean"
          }
        },
        "required": [
          "columns",
          "rows",
          "truncated"
        ],
        "title": "QueryResult",
        "type": "object"
      },
      "annotations": {
        "readOnlyHint": true,
        "openWorldHint": false
      }
    },
    "count": {
      "isError": false,
      "structuredContent": {
        "columns": [
          "pages"
        ],
        "rows": [
          [
            30
          ]
        ],
        "truncated": false
      }
    },
    "write": {
      "isError": true,
      "text": "Error executing tool run_query: Query rejected: the transaction is read-only (SQLSTATE 25006)."
    }
  }
}