Mcp Server Postgres Multi Schema

# PostgreSQL Multi-Schema MCP Server

A Model Context Protocol server that provides read-only access to PostgreSQL databases with enhanced multi-schema support. This server enables LLMs to inspect database schemas across multiple namespaces and execute read-only queries while maintaining schema isolation.

Key Features

• **Multi-Schema Support**: Explicitly specify which schemas to expose through command-line configuration
• **Schema Isolation**: Strict access control to only authorized schemas listed during server startup
• **Cross-Schema Discovery**: Unified view of tables across multiple schemas while maintaining schema boundaries
• **Metadata Security**: Filters system catalogs to only expose user-defined tables in specified schemas

Components

Tools

• **query**
  • Execute read-only SQL queries against the connected database
  • Input: `sql` (string): The SQL query to execute
  • All queries are executed within a READ ONLY transaction
  • Schema context maintained through search_path restriction

Resources

The server provides schema information for each table across authorized schemas:

• **Table Schemas** (`postgres://<host>/<db_schema>/<table>/schema`)
  • JSON schema information for each table
  • Includes column names, data types, and type modifiers
  • Automatically discovered from database metadata
  • Multi-schema support with explicit schema allow-list

Usage

The server requires a database URL and accepts a comma-separated list of schemas to expose:

``` npx -y mcp-server-postgres-multi-schema <database-url> [schemas] ```

• **database-url**: PostgreSQL connection string (e.g., `postgresql://localhost/mydb`)
• **schemas**: Comma-separated list of schemas to expose (defaults to ‘public’ if not specified)

Examples

```bash

Connect with default public schema

npx -y mcp-server-postgres-multi-schema postgresql://localhost/mydb

Connect with multiple schemas

npx -y mcp-server-postgres-multi-schema postgresql://localhost/mydb public,analytics,staging ```

Usage with Claude Desktop

Configure the “mcpServers” section in your `claude_desktop_config.json`:

NPX

```json { “mcpServers”: { “postgres”: { “command”: “npx”, “args”: [ “-y”, “mcp-server-postgres-multi-schema”, “postgresql://localhost/mydb”, “public,audit” ] } } } ```

License

This multi-schema MCP server is licensed under the MIT License. You may use, modify, and distribute the software according to the terms in the LICENSE file.