Always free

Klad is open source under the GNU AGPL v3 — no seats, no tiers, no usage limits, no card. And the whole of it is: there is no cut-down edition with the good parts held back for a plan.

There is one thing to know, and it is the AGPL's own condition rather than a price: what you build on it is open too. If that does not work for your product, there is a commercial licence, and that one is a conversation.

Open source

Free, forever

• Every feature, every package, every release — there is no cut-down edition
• Use it, modify it, fork it, redistribute it
• In return: what you ship it inside goes out under the AGPL too, so anyone it reaches — including over a network — can get that source
• Evaluating, prototyping or building internally, without shipping or hosting anything to third parties? Nothing to do at all

Commercial

Get in touch

• Closed-source and proprietary products, shipped or hosted
• No obligation to release your own source
• The right to distribute the library inside your application
• Terms — scope, seats, support, duration — agreed in writing, per company

yusuf@ozdemir.be

Something built for you

Neither licence is a service, and some of what people ask for is not a licence question at all:

• A chart that looks like your product. Everything the canvas draws is a theme token and everything on top of it is your own markup, so a design in your brand is configuration rather than a fork — the showcase on the home page is that, and nothing else.
• A layout or a feature you need and this does not have. The shape of a tree is a setting here precisely because there is more than one right answer; if yours is missing, it is worth a conversation.
• Getting it into your codebase. Migrating off whatever draws your charts today, wiring it to your data, making it fast on the size of tree you actually have.

Same address, and say which of these it is: yusuf@ozdemir.be.

Which one is you

The AGPL is enough — and you owe nothing and need to tell nobody — when:

• your project is itself released under the AGPL, or a licence the AGPL lets you combine into an AGPL whole;
• you are evaluating, prototyping or developing internally without shipping or hosting anything to third parties;
• your use is genuinely private — you modify it and never convey it or make it available over a network.

Its central condition is that anyone you convey the software to — including users who interact with it over a network — must be able to get the complete corresponding source of your version, under the AGPL, including your own code combined with it. This library runs in your users' browsers as part of your application, which is what makes that condition reach your application too.

You need the commercial licence when:

• you ship it inside a closed-source product, installed or delivered as a web application;
• you offer it as part of a hosted or SaaS service and do not want to release that service's source;
• you need to sublicense it to your own customers;
• your organisation's policy or contracts prohibit AGPL dependencies — a common reason on its own, regardless of how you use it.

Email yusuf@ozdemir.be with your company, the product it would go into, whether it ships to customers or is internal only, and rough scale. That is enough to quote against.

INFO

This page is a plain-language summary to help you work out which licence applies to you. It is not legal advice and it does not modify either licence. If the answer matters to you commercially, have your own counsel read the AGPL against your intended use.

Contributing

Contributions are accepted under the AGPL. Because the project is dual-licensed, a contributor licence agreement may be requested before a change can be merged — without one, the copyright holder cannot offer that contribution under the commercial licence. It is raised on the pull request; it is not a prerequisite for opening one.