mcp -postgres-multi-schema

This MCP server provides read-only access to one or more PostgreSQL schemas. It exposes a unified view of tables across authorized schemas while enforcing strict schema isolation, so your language models can inspect metadata and run read-only queries without accessing unauthorized objects. The server exposes two core capabilities: a query tool that executes read-only SQL within a restricted transaction context, and metadata access that surfaces table schemas across the allowed schemas. To use it, supply the Postgres connection string and a comma-separated list of schemas you want to expose. By default, if no schemas are provided, the server uses the public schema.

Typical workflow:

• Start the server with the database URL and an allow-list of schemas (e.g., public,audit,analytics).
• Use the query tool to run read-only SQL against the connected database. Each query runs in a READ ONLY transaction and respects the configured search_path so results reflect the allowed schemas.
• Retrieve table schemas and metadata, which are exposed per table across the authorized schemas, enabling schema-aware reasoning while maintaining isolation between schemas.

Prerequisites:

• Node.js and npm or npx installed on your system.
• Access to the target PostgreSQL database.

Installation steps:

1. Ensure Node.js is installed. You can verify with: node -v npm -v

2. Use NPX to launch the MCP server without a global install (recommended): npx -y mcp-server-postgres-multi-schema <database-url> <schemas>

   Example: npx -y mcp-server-postgres-multi-schema postgresql://localhost/mydb public,audit

3. (Optional) If you want to configure Claude Desktop or other clients, add an mcpServers entry with the appropriate command and arguments: { "mcpServers": { "postgres": { "command": "npx", "args": ["-y", "mcp-server-postgres-multi-schema", "postgresql://localhost/mydb", "public,audit"] } } }

Notes and tips:

• Schemas to expose are explicitly listed; other schemas are not accessible via the server.
• If you omit schemas, the default behavior is to expose the public schema.
• The server is read-only; write operations to the database are not permitted through the MCP tools.
• Ensure the database user referenced in the connection string has read permissions on the exposed schemas.
• The tooling surfaces table schemas and metadata in a per-table format, supporting cross-schema discovery while maintaining schema boundaries.
• If you run into connection or permission errors, verify network access to the PostgreSQL host and that the provided schemas exist and are accessible to the user.