Privacy Policy — Gantt Chart for Sheets

Last updated: 15 September 2026

The short version

Gantt Chart for Sheets has no permission to access the internet. Your spreadsheet data is read, turned into a chart, and written back into the same spreadsheet. None of it is transmitted anywhere, because the add-on has no ability to transmit anything.

We do not collect, store, sell, or share your personal information.

What the add-on can access

It requests exactly two permissions:

Permission Scope What it allows
See, edit, create and delete only the specific Google Sheets file you use it with spreadsheets.currentonly Read your task list and write the chart into a tab of that same file
Display and run third-party web content in prompts and sidebars script.container.ui Show the add-on’s menu and dialog boxes

It does not request permission to:

The last point is the important one. The add-on does not hold the script.external_request permission, so it cannot make network requests of any kind. Even if we wanted to send your data somewhere, the add-on could not do it.

What Google’s install screen asks for on top of that

When you install anything from the Google Workspace Marketplace, Google adds userinfo.email and userinfo.profile to the install screen — your name and your account’s email address. That is Google’s Marketplace requirement for every listed add-on and it is not removable by the developer; we tried to take it off the listing and Google puts it back.

The add-on’s own code does not read either of them: its script manifest declares only the two scopes in the table above, and nothing else is available to it at runtime. We do not receive your name or email address from an install, and we do not store them.

What is stored, and where

Two things are saved using Google’s own storage for add-ons, which lives inside your Google account and is not visible to us:

  1. Your display preferences — whether to skip weekends and whether to highlight the critical path. Stored per spreadsheet.
  2. Your licence key, if you have one — stored against your Google user so that a purchase applies in every spreadsheet you open. The key contains a plan name, an expiry date, and the payment reference from your purchase. It does not contain your name or email address.

Both are removed when you uninstall the add-on. You can clear the licence key yourself at any time: Extensions → Gantt Chart for Sheets → Licence → leave the box empty → OK.

What we receive when you buy a licence

Purchases are handled by our payment provider, not by this add-on. When you buy Pro, the payment provider processes your payment details and gives us an order reference and the email address to send your licence key to. We never see your card details.

We keep the order reference and email address only to issue your key, reissue it if you lose it, and meet the record-keeping we are legally required to do. We do not use them for marketing, and we do not share them with anyone.

Google Workspace APIs and AI models

Gantt Chart for Sheets does not use any Google Workspace API data to develop, improve, or train generalised or non-personalised AI or machine-learning models. It does not use AI or machine learning at all — scheduling is ordinary arithmetic.

Limited Use disclosure

The use and transfer of information received from Google APIs adheres to the Google API Services User Data Policy, including the Limited Use requirements.

Children

This add-on is a business tool and is not directed at children under 13.

Changes

If this policy changes, the “last updated” date above changes with it, and the current version is always published at this URL.

Contact

Questions about privacy, or a request to delete anything we hold:

slowgrain.dev@gmail.com

We reply within five working days.