[en] About the roadmap to Cozy version 3

These Frequently Asked Questions are about the blog post “On the road to Cozy version 3” we published on November 28. We recommend to read this blog post beforehand to give you an additional context. Feel free to comment or ask any additional questions below this post!

Why are you building Cozy 3.0?

We have been facing a problem with Cozy instances since the very beginning: they need a lot of RAM. Each instance needs at leat 1GB RAM, and there is no way to pool resources for several Cozy instances. If you wanted to run one Cozy instance per family member, you would need every instance to have its own Web server, its own database, etc. We want (and need!) to fix this. We want to pool some resources so that people can host more servers and consume less resources. It will be great for self-hosting and for professional hosting providers who want to build Cozy-based offers.

What are the benefits?

Here is our main goal for the new stack: each additional Cozy instance should cost next to nothing in terms of hosted resources. Thanks to the experience we have acquired with the first version of the stack, we will build a cleaner and more efficient back-end. We will get rid of our technical debt, which should also improve security. On top of this, the packaging will be better conceived, simpler, and less expensive to maintain. Last but not least: starting from scratch will pave the way for a great doc :slight_smile:

What about the downsides?

Most issues that we expect to see are linked to the transition to the new version. We’re restarting from scratch, which implies that we need to begin by something: it will be files and photos synchronisation and management. Other apps will come later. You won’t be able to use the same features initially. The application status will also change. We focus on the client side, and Cozy will not be able to host Node.js applications. All of this will take time: we plan to migrate from the old version to the new version in June 2017. For self-hosted users, images will be available in September 2017.

What is the future of applications ?

We want the Cozy ecosystem to focus on client-side apps. If you have written an app for Cozy that is based on the client-side model, there is very little change needed to become compatible with Cozy version 3.0. Your app probably uses cozy-client-sdk, so you’ll have to replace it by a new, similar library called Cozy-client-js. Cozy-client-js is compatible with both versions of the back-end. Cozy-client-js is documented and the existing tutorial will be updated shortly.

For the few developers of apps that have a server-side component, we now that the focus on client-side apps means significant refactoring. Switching to Cozy version 3 will bring a lot of positive things though, including built-in server-side features and a much larger reach.

Some of our apps like Emails were under development before this transition, we have paused them to maximize our chances of success.

What about self-hosting?

Self-hosted users will love Cozy 3.0, as it’s going to be a lot easier to install and maintain. Another great news: they will finally be able to deploy several instances on the same stack while using fewer resources, which will ease the management of mutiple personal instances.

If I want to self-host my Cozy, can I do it now or should I wait Cozy 3.0?

If you want to use Cozy right now, you still can install the current version and you should be able to migrate to the future version down the road. If your need is mostly around file synchronization and can wait a bit, then we suggest that you jump straight to Cozy version 3 when it becomes available: we’ll need Beta testers then!

When will the migration take place?

It’s too early to say. We plan to build a data export feature from Cozy that generates one big file with your data in it, and we want to be able to import this big file into Cozy 3.0. This export feature will also work if you want to move your Cozy instance from one place to another.

1 Like


First thanks for developing cozy, it’s a really great product.

But I am wondering if the current application stack will be maintained during the Cozy3 development phase. I am waiting for several fixes of the calendar. I hope not all devs focus on the v3, so that our bugs and features requests get fixed, so we don’t have to wait 1 year…

Keep on rockin’

Hello @Jambon,

Thanks for your encouragements :smile:

Sadly, all the development team is currently focused on the new version. All work on the current apps, including finishing the refactoring of Emails, has been put on hold. So, don’t expect any new features on the current apps before they get rewritten for the V3 :confused:

Could you list the fixes and enhancements you’re really waiting for?

Actually everything works fine, but I don’t want to wait more than one year just to have a “view week” in the calendar application. And a as the Github issue says, a lot of people also wants this feature to get implemented. Thanks

v3 sounds awesome! I can’t wait…just wish it was now :smile:

Thanks a lot, appreciated! :slight_smile: