Questions on add-on licenses

Add-on licenses tend to raise quite a few questions. What are the alternatives? Can I use them in my application? Free or commercial? How much?

This thread tries to answer those questions. Please add your questions to this thread. I’ll try to keep update this post with your questions.

Open source, Commercial Vaadin add-ons, the dual license, and You

Almost all of the (currently >500) add-ons available in the
Vaadin Directory
are free to use under the Apache 2.0 license, but there are also a few that have been released under some other open source license, a commercial license or a dual-license. Fortunately - license (or number of licenses to choose from) is always clearly marked on the add-on page.

Liberal open source licenses like Apache 2.0, LGPL, …

Most add-ons have been licensed with Apache 2.0 license. This is really good news - the license is compatible with almost any open source or commercial project needs you might have with all the freedoms you could hope. See
the license
for more details.

LGPL is in many respects quite similar, but with one major difference. If you make changes to the add-on itself, you must make those changes available with a compatible license. For applications just using the add-on this has no implications.

Restrictive open source licenses like AGPL and GPL

GPL requires that if you include an add-on with that license, you must make the source code of your application available under a compatible license to everyone
who gets the runtime
(war/…) of your application. If you just host the application yourself and your users use it from web, there are no requirements to open source your application.

AGPL license
is a slight derivation of the GPL license, that adds a requirement for the availability of the source code
to anyone who can use the system
. In practice this means that you must make your full source code available even if you do not “ship” your software in the traditional sense, but instead offer it as a service over the internet., eg. the SaaS model.

The commercial option: choosing CVAL

Commercial Vaadin Add-on License, or CVAL
grants your team the full rights to use the add-on against a license fee. If you choose to use CVAL, you are free to use these add-ons in a closed source application.

Instead of a flat fee per add-on the CVAL scales with your development team size. This means that all developers working in a project the uses a CVAL licensed add-on need a personal CVAL license for that add-on. So, if your team has 3 developers you must purchase 3 CVAL licenses. Note that there are subtle differences between CVALv1, CVALv2 and CVALv3. All new add-ons use CVALv3.

The CVAL licenses are transferable within your organization for free, but at all times every developer working in the project must have a CVAL license for every commercial Vaadin add-on used in the project. You can also use a single CVAL in several projects, so you don’t need to pay the associated fee for every project. Because CVAL requires you to delete license keys and commercial add-ons from the computers of the developer who is transferring license, it is unpractical to do transfer this on a regular basis. CVAL is not a “floating license”.

You can think CVAL this as a “photoshop box” on the developers table and the project as a set of pictures. Everyone editing pictures needs a photoshop, but when one stops in the project, he can give photoshop box to someone else. Also each developer can work in unlimited number of projects with the same photoshop. Only difference here is that CVAL license requires all participants to have the license - even the backend guys who might not even touch the part of the code related to the add-on requiring the license.

The full definition of who constitutes a developer and thus requires a CVAL license can be found in the license text, but a good rule of thumb is that if the person has commit access to the project repository he/she probably needs a CVAL license.

Summary: so, do I need to purchase CVAL licenses for a AGPL/CVAL dual-licensed add-on or not?

  • First, check that the add-on is available under AGPL. Currently only TouchKit is available with AGPL and CVAL. Other Pro Tools are only available under CVAL.

  • We planning to release our application source code, do we need to purchase CVAL licenses?


    as long as you release your source code under a license that’s compatible with the AGPL.

  • We are building an application that will only be made available over the internet, deployed and run by ourselves, but will not release the source code to the users. Do we need to purchase CVAL licenses?


    This is the SaaS model, and it can’t be used with AGPL without releasing your source code. It does not matter if you charge a fee from your users or not.

  • We are building a application that will only be deployed to the intranets of our customers, and we are not releasing our source code to our customers. Do we need to purchase CVAL licenses?


    This is a variation of the SaaS model even if the application is not available through the public internet.

  • We are building a intranet application that will only be accessed by our own employees, and the application can’t be accessed from the internet. Do we need to purchase CVAL licenses?

    It depends.

    You can use the AGPL option if all users have access to the source code, and have the right to make improvements to the application. If you can’t fulfill both of these requirements you need to purchase CVAL licenses.

How many licenses do I need?

blog post about this

How could I optimize use of Vaadin Pro Account alongside the CVAL licenses purchased from Directory

blog post about this

List of dual licensed add-ons

The following add-ons are currently published under a dual CVAL / AGPL license.

List of add-ons available only with CVAL license

The following add-ons always require CVAL license.

AFAIK AGPL allows a developer to modify the source code of an add-on. So my question is: Does CVAL allow that as well?

Yes. Source code can be freely modified.

The requirement that we must have 20 licenses if we have 20 developers in the project, although only one of them is directly programming using the CVAL piece is the difficulty for us in this licensing model.

A different licensing model followed by some others, including, is something that works for us. Considering how long that firm has been around selling UI components, I guess it works for them as well. Their model is to pay a nominal flat fee per project, irrespective of how many developers are involved.

I think the new “all-you-can-eat” support model which includes all CVAL components and test bench is also based on number of developers in a project, irrespective of the number of “Vaadin developers” in the project.

I’m sure you have thought long and hard about arriving at a fair licensing model. I just wanted to you to hear a different voice that wishes to use your CVAL pieces, but is hindered by the CVAL licensing model. I hope you will consider a different model in future.


Im looking to integrate the Calendar add-on into an app for a client (closed-source). I understand that i will need to purchase a CVAL license per developer but how long does the license last? Is it a one off payment or annual fee?



CVAL -license is a one off fee. Thus it is fairly comparable to buying boxed software licenses for developers. License right to a developer to develop unlimited number of applications with the license with no yearly maintenance or other fees. Also there is no runtime or deployment license requirements at all.

Upcoming Vaadin Pro Account subscription will be an alternative way of obtaining a commercial license. Because of its subscription nature, it is more like “renting” the “boxed software” license. The license is only valid while the subscription is active. This is possible because there is no runtime licensing requirements - all the users of the software incorporating the licensed add-on can continue to use it after developer chooses to end the subscription.


I’m a freelance software developer with no employees. Now I am developing a product, in which I intend to use the commercial
calendar add-on
. The product belongs to me, so I am developer and client in one person.

Is it legal for me to buy one developer license for 149 $ and use it in a publicly accessible web application?

Thanks in advance


Yes, as long as you are the only one contributing code to the application.

The full license text is
available here
. The relevant points are:

I’m sorry to belabor this point. Here is the license model of a competing UI toolkit. I have changed its name to XYZ to be polite. Will you please consider changing the CVAL license to be somewhat similar to this XYZ license so that a license is required only if the developer calls Vaadin API, rather than requiring everyone to have a license?

I like Vaadin technology and people. But the CVAL license is hard to use in our projects. For example, I have a project that might soon have 20 developers. Only one or two will be Vaadin developers. But I need to buy 20 licenses if we were to use a CVAL component or tool.

Thank you for the proposal. You are not the only one who has asked for this change. We will seriously consider how to address this issue.

My company develops its own application framework in house (Tang). It’s similar to your xmlui idea you have been working on, but … different. I tend do describe it as a language unto itself - a DSL for developing applications if you will.

Tang is compiled in to a jar, and we then implement our application UIs using Tang, including only the tang jar. We have only two developers who develop and commit to Tang, but then we have many developers who use Tang to implement other applications. Seeing as we only have two committers to the Tang project, will this require only two CVAL licenses? Or do the client developers require CVAL licenses too?


If Tang uses an add-on licensed with CVAL, you could say that it is kind of wrapper that provides the add-on functionality to the rest of the developers. In that case, also the rest of the team would have have CVAL license to add-on - not just the committers to Tang.

Fair enough. Thanks

We have been preparing a version 2 of the CVAL license that addresses your concerns. The license is largely the same as the current one, but defines the “use of a licensed add-on component” more carefully. Before releasing the new license, it would be great to be able to get feedback on this core definition in the license.

In the CVAL version 2 draft, this use is defined as:

If anyone wants to comment on this, please do.


Where can I buy the Calendar add-on?

When I go to;jsessionid=5718C1966002AFEC0FD58AFFAB3CBE9E ,

then enter my order details and press the “Buy” button, I get the message “Please login to use the PayPal Sandbox features.” (even if I’m logged in in PayPal).

Thanks in advance


Hi Dmitri,

could you please try again your purchase through the Directory. The purchase process should now be available through PayPal again.

Please let us know if you still have any issues with the purchase and we’ll be happy to help.

I wanna ask the same question , is anything have changed (since a month+)? If only I use an add-on , other develeports still need to buy CVAL license ?


The new CVALv2 license is coming really soon now. The license itself is already available at

New versions of all
Vaadin Pro Add-ons
will be packaged shortly and released with this new license.

Read more about CVALv2 on my new blog post:

Hello to all of you.

I have question about using Vaadin TouchKit for my application.

My simple web app can be found here:

I wanna rebuild this app to be created in TouchKit

Can we please clear the air?

Can or can not I use Vaadin TouchKit for free under AGPL license?

Thank you.