Privacy Model

NVEIL is designed so that raw data never leaves your machine.

What is sent to the server

When you call generate_spec(), the Toolkit sends only metadata:

Sent	Example
Column names	"revenue", "region", "date"
Column types	INTEGER, FLOAT, STRING, DATETIME
Aggregate statistics	min, max, distinct count, row count
Your prompt	"Show revenue by region"

What stays local

Stays local	Why
Raw data values	Never sent — the server only sees aggregate stats
DataFrames	Passed by reference to local pipeline and renderer
Rendered figures	Generated locally by the dive engine
.nveil files	Written and read on your machine; contain the spec only, never raw data

The flow in detail

graph TD
    A["Your DataFrame"] --> B["Toolkit: extract metadata"]
    B --> C["Metadata + prompt"]
    C -->|"sent to server"| D["NVEIL Server"]
    D -->|"returns spec"| E["Visualization spec"]
    E --> F["Toolkit: render locally"]
    A -->|"stays local"| F
    F --> G["Interactive figure"]

    style A fill:#2d5,stroke:#fff,color:#fff
    style F fill:#2d5,stroke:#fff,color:#fff
    style G fill:#2d5,stroke:#fff,color:#fff
    style D fill:#d52,stroke:#fff,color:#fff

Green = local. Red = server-side. The data path (green) never crosses to the server.

Transport security

All communication with the NVEIL server uses HTTPS/TLS.