Secure Schema MCP server

Secure Schema MCP

<!-- mcp-name: io.github.Siddharth-coder13/secure-schema -->

A read-only MCP server that gives AI coding tools database structure without exposing row data. It returns table and view names, columns, types, keys, and relationships in a compact format designed to reduce LLM token usage.

What it exposes

Schema metadata can still be sensitive. A column name such as ssn reveals information even without values, so production deployments should always use the table allowlist and a dedicated database account.

Requirements

• An MCP-compatible client such as Cursor or Codex
• A reachable SQLite, PostgreSQL, or MySQL database
• Python 3.12 or newer when installing without uvx

SQLite support uses Python's built-in driver. PostgreSQL and MySQL drivers are included. Other SQLAlchemy dialects are not tested or bundled in v1.

Configure your IDE

The recommended setup uses uvx to download and run the published Python package in an isolated environment. You do not need to clone this repository or start the server separately. Your IDE launches it over stdio when needed.

Cursor

Add this server to your Cursor MCP configuration:

{
  "mcpServers": {
    "secure-schema": {
      "command": "uvx",
      "args": ["mcp-secure-schema"],
      "env": {
        "DATABASE_URL": "postgresql+psycopg2://schema_reader:password@localhost:5432/appdb",
        "DATABASE_SCHEMA": "public",
        "ALLOWED_TABLES": "users,orders,products",
        "SECURE_SCHEMA_ENV": "production",
        "FASTMCP_CHECK_FOR_UPDATES": "off",
        "FASTMCP_SHOW_SERVER_BANNER": "false"
      }
    }
  }
}

Restart or reload Cursor after changing its MCP configuration.

Codex

Add this to ~/.codex/config.toml or a trusted project's .codex/config.toml:

[mcp_servers.secure-schema]
command = "uvx"
args = ["mcp-secure-schema"]
enabled_tools = ["schema_overview", "list_tables", "inspect_table"]
startup_timeout_sec = 30
tool_timeout_sec = 30

[mcp_servers.secure-schema.env]
DATABASE_URL = "postgresql+psycopg2://schema_reader:password@localhost:5432/appdb"
DATABASE_SCHEMA = "public"
ALLOWED_TABLES = "users,orders,products"
SECURE_SCHEMA_ENV = "production"
FASTMCP_CHECK_FOR_UPDATES = "off"
FASTMCP_SHOW_SERVER_BANNER = "false"

Install once instead

If you prefer a persistent installation:

pipx install mcp-secure-schema

Then use "command": "mcp-secure-schema" with an empty args list in the IDE configuration.

Database URLs

Secure Schema MCP accepts SQLAlchemy connection URLs:

# SQLite (absolute path)
sqlite:////Users/me/project/app.db

# PostgreSQL
postgresql+psycopg2://user:password@localhost:5432/appdb

# Remote PostgreSQL with certificate verification
postgresql+psycopg2://user:password@db.example.com:5432/appdb?sslmode=verify-full&sslrootcert=/path/to/ca.pem

# MySQL
mysql+pymysql://user:password@localhost:3306/appdb

Percent-encode special characters in URL usernames and passwords. For example, @ in a password becomes %40.

Local and remote databases use the same MCP configuration. For remote databases, the machine running the IDE must also have working DNS, network access, firewall permission, and valid TLS settings.

Configuration

Shortened. The full README is on GitHub.