Extensions + Marketplace

Marketplace

Being a vscode based editor, VSCodium gets additional features by installing Visual Studio Code extensions. Unfortunately, as Microsoft prohibits usages of the Microsoft marketplace by any other products or redistribution of .vsix files from it, in order to use Visual Studio Code extensions in non-Microsoft products those need to be installed differently.

By default, the product.json file is set up to use open-vsx.org as extension gallery, which has an adapter to the Marketplace API used by Visual Studio Code. Since that is a rather new project, you will likely miss some extensions you know from the Visual Studio Marketplace. You have the following options to obtain such missing extensions:

Ask the extension maintainers to publish to open-vsx.org in addition to the Visual Studio Marketplace. The publishing process is documented in the Open VSX Wiki.
Create a pull request to this repository to have the @open-vsx service account publish the extensions for you.
Download and install the vsix files, for example from the release page in their source repository.

How to use the Open VSX Registry

As noted above, the Open VSX Registry is the pre-set extension gallery in VSCodium. Using the extension view in VSCodium will therefore by default use it. See this article for more information on the motivation behind Open VSX.

How to use a different extension gallery

You can switch from the pre-set Open VSX Registry by configuring the endpoints using the following solutions.

You can either use the following environment variables:

VSCODE_GALLERY_SERVICE_URL (required)
VSCODE_GALLERY_ITEM_URL (required)
VSCODE_GALLERY_CACHE_URL
VSCODE_GALLERY_CONTROL_URL
VSCODE_GALLERY_EXTENSION_URL_TEMPLATE (required)
VSCODE_GALLERY_RESOURCE_URL_TEMPLATE

Or by creating a custom product.json at the following location (replace VSCodium by VSCodium - Insiders if you use that):

Windows: %APPDATA%\VSCodium or %USERPROFILE%\AppData\Roaming\VSCodium
macOS: ~/Library/Application Support/VSCodium
Linux: $XDG_CONFIG_HOME/VSCodium or ~/.config/VSCodium

with the content like:

{
  "extensionsGallery": {
    "serviceUrl": "", // required
    "itemUrl": "", // required
    "cacheUrl": "",
    "controlUrl": "",
    "extensionUrlTemplate": "", // required
    "resourceUrlTemplate": "",
  }
}

How to self-host your own extension gallery

Individual developers and enterprise companies in regulated or security-conscious industries can self-host their own extension gallery.

There are likely other options, but the following were reported to work:

Open VSX eclipse open-source project While the public instance which is run by the Eclipse Foundation is the pre-set endpoint in VSCodium, you can host your own instance.

Open VSX is a vendor-neutral open-source alternative to the Visual Studio Marketplace. It provides a server application that manages Visual Studio Code extensions in a database, a web application similar to the Visual Studio Marketplace, and a command-line tool for publishing extensions similar to vsce.
code-marketplace open-source project

code-marketplace is a self-contained go binary that does not have a frontend or any mechanisms for extension authors to add or update extensions in the marketplace. It simply reads extensions from file storage and provides an API for VSCode compatible editors to consume.

Visual Studio Marketplace

As with any online service, ensure you've understood its terms of use which include:

Marketplace Offerings are intended for use only with Visual Studio Products and Services and you may only install and use Marketplace Offerings with Visual Studio Products and Services.

So, we can't provide any help if you intend to infringe their terms of use.

Also note that this extension gallery hosts multiple extensions that are non-free and have license-agreements that explicitly forbid using them in non-Microsoft products, along with using telemetry.

Proprietary Debugging Tools

The debugger provided with Microsoft's C# extension as well as the (Windows) debugger provided with their C++ extension are very restrictively licensed to only work with the official Visual Studio Code build. See this comment in the C# extension repo and this comment in the C++ extension repo.

A workaround exists to get debugging working in C# projects, by using Samsung's opensource netcoredbg package. See this comment for instructions on how to set that up.

Proprietary Extensions

Like the debuggers mentioned above, some extensions you may find in the marketplace (like the Remote Development Extensions) only function with the official Visual Studio Code build. You can work around this by adding the extension's internal ID (found on the extension's page) to the extensionAllowedProposedApi property of the product.json in your VSCodium installation. For example:

  "extensionAllowedProposedApi": [
    // ...
    "ms-vscode-remote.vscode-remote-extensionpack",
    "ms-vscode-remote.remote-wsl",
    // ...
  ],

In some cases, the above change won't help because the extension is hard-coded to only work with the official Visual Studio Code product.

Using the "VSIX Manager" Extension

The VSIX Manager extension provides a powerful and user-friendly interface for managing .vsix files directly within VSCodium. Its author is the main maintainer of VSCodium ;)

It is particularly beneficial for:

Support for Multiple Marketplaces: Seamlessly install and manage extensions from several marketplaces at the same time, allowing access to a broader range of extensions.
Local Files: Manage a collection of .vsix files stored locally.
GitHub/Forgejo Release: Install the extension directly from its GitHub/Forgejo release pages.
Fallback Options

Use Cases

Developers working offline can easily manage .vsix files.
Teams can distribute specific versions of extensions across systems.
Enterprises with restricted environments can maintain control over installed extensions.
Users can connect to multiple marketplaces and access a wider range of extensions or switch seamlessly between them.

Marketplace Support

The VSIX Manager extension supports managing extensions from several marketplaces simultaneously. This feature enables:

Access to Diverse Extensions: Install extensions from different sources like Open VSX or private repositories.
Fallback Options: Ensure extension availability even if one marketplace is temporarily inaccessible.
Enterprise Flexibility: Use private or self-hosted marketplaces alongside public ones to meet security and compliance requirements.
Custom Configurations: Prioritize specific marketplaces for particular needs while keeping access to others.