mcp-pgsql-query

MCP server for read-only PostgreSQL queries. Only SELECT statements are allowed — all other operations are rejected at the SQL validation layer.

Features

• SELECT-only enforcement (INSERT/UPDATE/DELETE/DDL/COPY all blocked)
• AST-level SQL analysis via sqlglot to catch injection and embedded write operations
• Blocks dangerous functions: pg_read_file, pg_write_file, lo_export, dblink, etc.
• Stacked statement prevention (; separated statements)
• Returns results as JSON with column names, rows, and truncation indicator

Configuration

Set these environment variables:

Claude Desktop configuration

{
  "mcpServers": {
    "pgsql": {
      "command": "uvx",
      "args": ["mcp-pgsql-query@latest"],
      "env": {
        "PG_HOST": "your-server",
        "PG_DATABASE": "your-db",
        "PG_USERNAME": "your-user",
        "PG_PASSWORD": "your-password"
      }
    }
  }
}

Tool

query_pgsql

Run a read-only SELECT query against the configured PostgreSQL database.

Parameters:

• sql (required) — PostgreSQL SELECT statement
• max_rows (optional) — Maximum rows to return, default 100, max 1000