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
# 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
{
"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.