How VSCodium Removes Microsoft Telemetry and Keeps the Marketplace Open

Why the Telemetry‑Free Build Matters

When you install Visual Studio Code from Microsoft’s website, the installer bundles a telemetry module that silently reports usage data to Azure. For teams that must avoid sending any data outside their network, that default build is unacceptable. VSCodium solves the problem by building the same source tree but stripping the telemetry code before packaging the binary. The result is a fully free‑and‑open‑source editor that still feels like VS Code.

Engineering Decision: Automated Telemetry Stripping

The core decision is to replace a manual “remove the telemetry folder” step with an automated build script. The VSCodium build pipeline runs on GitHub Actions, checks out the official vscode repository, applies a patch that deletes src/vs/platform/telemetry and any references to it, and then compiles the editor for the target platform. The process is fully reproducible and version‑controlled, so anyone can verify that no telemetry code remains.

Key Build Steps

1. Checkout VS Code source

   git clone https://github.com/microsoft/vscode.git
   cd vscode
   

2. Apply the telemetry‑removal patch

   # The patch lives in the VSCodium repo; fetch it
   curl -O https://raw.githubusercontent.com/VSCodium/vscodium/master/patches/remove-telemetry.patch
   patch -p1 < remove-telemetry.patch
   

3. Install dependencies

   npm install
   

4. Build the editor

   npm run compile
   

5. Package for distribution

   npm run package
   

After npm run package finishes, the out/ directory contains the built executable. Running ./out/monaco-editor/vscode/bin/code --help shows the same command‑line options as VS Code but without any telemetry flags.

Marketplace Replacement: Open VSX

Microsoft’s original build points the extension marketplace to https://marketplace.visualstudio.com. VSCodium redirects those requests to the Open VSX Registry (https://open-vsx.org), an open‑source alternative that hosts the same extensions. The build script patches the vs/platform/extensionManagement/common/extensionManagement.ts file to change the marketplace URL constant.

Verifying the Marketplace Switch

1. Open VSCodium and press Ctrl+Shift+X to open the Extensions view. 2. Search for any extension, e.g., “Python”. 3. Use your browser’s developer tools or a tool like tcpdump to watch the network traffic.

sudo tcpdump -i any -w vscodium_traffic.pcap host open-vsx.org

4. In the capture, you should see GET requests to https://open-vsx.org/api/extensions/.../versions and not to marketplace.visualstudio.com.

Limitations and Trade‑offs

• Extension Compatibility: Some extensions rely on the Microsoft Marketplace API and will refuse to install or enable in VSCodium. Check the extension’s README for “VSCodium” support.
• Remote Development: The official “Remote - SSH” and “Remote - Containers” extensions are tied to Microsoft’s services. VSCodium users must install the open‑source equivalents or re‑configure the extensions manually.
• Update Channel: VSCodium does not use Microsoft’s update server. Instead, updates are published by the community on GitHub releases. Users must manually download the latest binary or set up a script to fetch releases.

Practical Checklist for Your Team

1. Verify the build script version: git log -1 --pretty=format:"%h %s" should show a commit that applies the telemetry patch.
2. Run the --version flag: ./out/monaco-editor/vscode/bin/code --version should match the VS Code source tag you built.
3. Check the About dialog: it should display “VSCodium” instead of “Microsoft Visual Studio Code”.
4. Run a quick extension install test: code --install-extension ms-python.python should fetch from Open VSX.
5. Optional: set up a CI pipeline that triggers on new VSCodium releases and automatically pushes the binary to your internal artifact repository.

Conclusion

VSCodium’s engineering decision to automate telemetry removal and marketplace redirection gives teams a lightweight, privacy‑respectful alternative to VS Code. By following the build steps above, you can produce a custom binary that meets your compliance requirements while still enjoying the rich ecosystem of extensions. Just remember to vet extensions for marketplace compatibility and to manage updates manually.