No2SQL 1.0.3

No2SQL

No2SQL is an MCP server and NuGet package that helps you move from MongoDB to SQL by:

• discovering collections and relationship candidates,
• generating SQL schema scripts,
• generating SQL seed (INSERT) statements,
• producing ER diagrams in Mermaid, PlantUML, and GraphViz DOT formats.

Who This Is For

• Teams migrating from MongoDB to relational databases
• Engineers documenting NoSQL structures in ERD form
• AI-assisted workflows where Copilot can call data-migration tools through MCP

Quick Start

1. Configure MongoDB connection

Set your MongoDB connection string via the environment variable NO2SQL_MONGO (recommended).

Example format:

mongodb+srv://<username>:<password>@<cluster-host>/<database>?retryWrites=true&w=majority

You can also set it via No2SQL/appsettings.json under ConnectionStrings:MongoDb.

Installing the No2SQL MCP Server

The No2SQL MCP server is distributed as a standalone executable inside a NuGet package.
You do NOT need .NET installed and you do NOT need a .NET project.

1. Download the package

Option A — Using curl

curl -L https://www.nuget.org/api/v2/package/No2SQL/1.0.3 -o No2SQL.1.0.3.nupkg

Option B — Using PowerShell

Invoke-WebRequest https://www.nuget.org/api/v2/package/No2SQL/1.0.3 -OutFile No2SQL.1.0.3.nupkg

Option C — Download manually
Visit https://www.nuget.org/packages/No2SQL and click Download package.

2. Extract the package

A .nupkg is a ZIP archive:

unzip No2SQL.1.0.3.nupkg -d no2sql

Executables will be located under:

/tools/win-x64/No2SQL.exe
/tools/linux-x64/No2SQL
/tools/osx-arm64/No2SQL

3. Configure your MCP client

⚠️ Important: Always include the env block with your MongoDB connection string. Without it, the server starts but cannot reach your database and tools will silently fail.

VS Code (recommended)

Add to your User Settings JSON (Ctrl+Shift+P → Open User Settings (JSON)):

"mcp.servers": {
  "no2sql": {
    "command": "path/to/no2sql/tools/win-x64/No2SQL.exe",
    "env": {
      "NO2SQL_MONGO": "your-mongodb-connection-string",
      "NO2SQL_BLOCK_SYSTEM_DATABASES": "true"
    }
  }
}

Alternatively, VS Code will create a dedicated mcp.json file (at %APPDATA%\Code\User\mcp.json on Windows). If you use that route, make sure to add the env block there too:

{
  "servers": {
    "no2sql": {
      "type": "stdio",
      "command": "path/to/no2sql/tools/win-x64/No2SQL.exe",
      "args": [],
      "env": {
        "NO2SQL_MONGO": "your-mongodb-connection-string",
        "NO2SQL_BLOCK_SYSTEM_DATABASES": "true"
      }
    }
  },
  "inputs": []
}

After saving, reload the window: Ctrl+Shift+P → Developer: Reload Window.

Claude Desktop

Add to claude_desktop_config.json:

{
  "mcpServers": {
    "no2sql": {
      "command": "path/to/no2sql/tools/win-x64/No2SQL.exe",
      "env": {
        "NO2SQL_MONGO": "your-mongodb-connection-string",
        "NO2SQL_BLOCK_SYSTEM_DATABASES": "true"
      }
    }
  }
}

GitHub Copilot MCP

{
  "mcpServers": {
    "no2sql": {
      "command": "path/to/no2sql/tools/win-x64/No2SQL.exe",
      "env": {
        "NO2SQL_MONGO": "your-mongodb-connection-string",
        "NO2SQL_BLOCK_SYSTEM_DATABASES": "true"
      }
    }
  }
}

4. Verify the server is registered (VS Code)

After reloading, open the Command Palette (Ctrl+Shift+P) and run MCP: List Servers.
You should see no2sql listed. If it doesn't appear, double-check the executable path and that your settings were saved to the correct file.

5. Test it in Copilot Chat

1. Open Copilot Chat in VS Code
2. Click the tools icon (plug or hammer icon) at the bottom of the chat input
3. Confirm no2sql appears in the tools list and is enabled
4. Type a prompt — Copilot will route it through No2SQL automatically:

Use No2SQL to list my MongoDB databases.

If the tools icon shows no2sql and the prompt returns your database list, you're fully set up.

More example prompts:

Infer relationships for database mydb.
Generate SQL schema for database mydb.
Generate Mermaid ERD for mydb using SQL source.
Generate SQL INSERT statements for collection orders in mydb.

MCP Tools Exposed

Security Guardrails

No2SQL includes input validation and database access guardrails.

Environment variables:

• NO2SQL_ALLOWED_DATABASES — optional comma-separated database allowlist
• NO2SQL_BLOCK_SYSTEM_DATABASES — defaults to true; blocks admin, config, local

Tool inputs are validated for:

• identifier format and length
• diagram source values (sql, mongo, auto)
• relationship override fields
• prompt-injection style marker patterns

Recommended production baseline:

• Set NO2SQL_ALLOWED_DATABASES to a strict allowlist
• Keep NO2SQL_BLOCK_SYSTEM_DATABASES=true

Build, Test, Publish

Build solution:

dotnet build No2SQL.sln

Run test harness:

dotnet run --project No2SQL.Test

Pack NuGet:

dotnet pack -c Release

Publish NuGet package:

dotnet nuget push **/bin/Release/*.nupkg --api-key <your-api-key> --source https://api.nuget.org/v3/index.json

Local Test Defaults

No2SQL.Test/Program.cs supports environment variable overrides:

CLI arguments take precedence over environment variables.

Contributions

Forks and derivative works are welcome under the MIT License.

Changes to the official No2SQL repository are accepted at the maintainer's discretion. Submitting a pull request does not guarantee inclusion.

License

No2SQL is licensed under the MIT License.

Copyright (c) 2026 Preet Talati

"No2SQL" is a trademark of Preet Talati.