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:
- **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
Usage with Claude Desktop
Configure the "mcpServers" section in your `claude_desktop_config.json`:
NPX
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.