How to install extensions in theia browsers IDE ?

My steps:

  1. use docker image “theia-java” to start theia;

  2. use command “yarn add @theia-java-debug” to install extensions, and text “@theia/java-debug”: “^0.12.0” appears file “package.json”;

  3. use command “yarn theia build” rebuild;

  4. restart the docker container;

but it desn’t work, There’s no have extensions on borwers.

[original thread by HuZhengWei]

@marc-dumais @vince-fugnitto Could you help please?

@cdisk you are using the theia-java image? Is it pulled from dockerhub or are you building the image from sources (ex:


@vince-fugnitto I pulled from dockerhub, I using this command “docker run theiaide/theia-java:0.12.0” to start container.

You can always use VS Code extensions for Java development, but in order to modify the docker images, a rebuild is necessary at the moment.


@vince-fugnitto Thank you,but I still have some questions, could you explain me more?
When we modify the package.json file or run command yarn add java-debug, do I need to rebuild the docker image or the Theia directory?
because I ran the yarn theia build command to rebuild,logs no error, but when I restart theia container and open browser,I can’t find the deubg extensions, The browser layout still the default layout, no change.

The docker image will need to be rebuilt. Please keep in mind that this is only the case for Docker images. If you were to build an IDE yourself as described in then the command you referenced will be enough.


@vince-fugnitto what prevents the docker image to support extensions? It looks like a normal build from the dockerfile

Which image specifically are you looking to support vscode extensions?


oops, didn’t notice your response… thanks!

I was looking for a way to add extensions to a docker image, but building on the official theia one. Specifically I would eventually like to build an Elixir version, or better have one with Elixir support, as it’s unlikely that Elixir is the only language integration required in an Elixir project.