SchemaLens-Exillar — Quick Start Guide

CLI tool that connects to a database (PostgreSQL, MySQL, SQL Server, Snowflake, Databricks, or MongoDB), reads the schema, and uses an LLM to generate documentation automatically. No frontend. No manual input beyond a one-time setup wizard.

Requirements

1. Python 3.11 or newer
2. Internet access — to install the package, connect to your database, and call the LLM via OpenRouter
3. Your database credentials (host, username, password, etc.)
4. An OpenRouter API key (openrouter.ai) — you're billed by OpenRouter directly for usage, regardless of whether you pick GPT or Gemini in the wizard
5. SQL Server only: an ODBC Driver for SQL Server installed on your machine (not installed by pip — download here)
6. Linux only, for diagram PNG export: libcairo2 system package (sudo apt install libcairo2)

Step-by-step

1. Create a virtual environment (recommended and required)

Don't install directly into your system Python — always use a virtual environment to avoid conflicts with other packages.

python -m venv venv

Activate it:

• Windows: venv\Scripts\activate
• Mac/Linux: source venv/bin/activate

2. Install (pick the extra matching your database)

pip install SchemaLens-Exillar[postgres]

Options: [postgres], [mysql], [sqlserver], [snowflake], [databricks], [mongodb], or [all] for every driver.

3. Run

schemalens-exillar

4. Answer the wizard's questions

• Pick your database type (enter the number)
• Choose to paste a full connection string, or enter host/port/username/password one by one
• (Optional) Type specific schema names to limit scope (comma-separated, e.g. public,sales), or press Enter to include all schemas
• Choose which model to use: GPT or Gemini
• Enter your OpenRouter API key — never saved, asked fresh every run
• Choose where to save the output (press Enter for current folder)

5. Wait for it to finish

You'll see a simple progress line per batch of tables being processed.

6. Open your files

Three files are created in the folder you chose:

• er_diagram_<yourdatabase>.html — interactive diagram, open in any browser
• schema_documentation_<yourdatabase>.xlsx — Excel workbook with full column descriptions
• Suggestion_Report_<yourdatabase>.docx — suggested keys/relationships for review

Run it again anytime — older files are never overwritten, each run adds a number + timestamp.

Each new session, reactivate the venv first (venv\Scripts\activate / source venv/bin/activate) before running schemalens-exillar again.

Note: nothing is ever saved to disk — no .env file, no saved password, no saved API key. You'll enter your credentials fresh every time you run it.

License

MIT — see LICENSE.