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Glass makes it easy to discover and install extensions to enhance your development experience. This guide covers all the ways to install extensions.

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Opening the Extensions View

The Extensions view is your central hub for managing extensions.
1

Open the Extensions panel

Use one of these methods:
  • Press Cmd+Shift+X (macOS) or Ctrl+Shift+X (Linux/Windows)
  • Open the command palette and search for “Extensions”
  • Click the Extensions icon in the sidebar
2

Browse available extensions

The Extensions view shows:
  • All available extensions from the registry
  • Installed extensions (marked with a checkmark)
  • Extension descriptions and metadata

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Installing Published Extensions

Published extensions are distributed through the Glass extension registry and are the easiest to install.

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From the Extensions View

1

Search for an extension

Use the search bar at the top to filter extensions by name, description, or functionality:
Search extensions...
2

Review extension details

Each extension card shows:
  • Extension name and version
  • Description
  • Author information
  • Download count
  • What it provides (themes, languages, etc.)
3

Click Install

Click the Install button on the extension card. Glass will:
  • Download the extension from the registry
  • Verify its integrity
  • Install it to your extensions directory
  • Load it automatically
For theme extensions, Glass automatically opens the theme selector after installation so you can immediately apply the new theme.

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Installation Process

When you install an extension:
  1. Download: Glass downloads the extension package (.tar.gz archive) from the registry
  2. Verification: The package is verified for integrity and compatibility
  3. Extraction: The archive is extracted to ~/.config/glass/extensions/installed/<extension-id>/
  4. Loading: The extension is loaded and its resources are registered
  5. Activation: Extension features become immediately available

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Filtering Extensions

You can filter extensions by what they provide:
View only extensions that add programming language support:
Extensions: Languages

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Installing Development Extensions

Development extensions allow you to install extensions from a local directory. This is useful for:
  • Testing extensions you’re developing
  • Installing unpublished extensions
  • Debugging extension issues

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Installing from a Local Directory

1

Prepare your extension

Ensure your extension directory contains a valid extension.toml manifest file:
id = "my-extension"
name = "My Extension"
version = "0.1.0"
schema_version = 1
authors = ["Your Name"]
description = "My custom extension"

[lib]
kind = "Rust"
2

Open the command palette

Press Cmd+Shift+P (macOS) or Ctrl+Shift+P (Linux/Windows)
3

Run Install Dev Extension

Search for and select:
Extensions: Install Dev Extension
4

Select the extension directory

A file picker will open. Navigate to and select your extension’s root directory (the one containing extension.toml)
5

Wait for compilation

Glass will:
  • Compile your extension (if it contains Rust code)
  • Create a symlink from the installed directory to your source directory
  • Load the extension
Dev extensions create a symbolic link to your source directory, so changes you make are reflected immediately (after rebuilding if necessary).

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Development Extension Behavior

Overriding Published Extensions If you install a dev extension with the same ID as an already-installed published extension:
  • The dev extension takes precedence
  • The published extension is automatically uninstalled
  • This allows testing local changes against production extensions
Rebuilding Dev Extensions For Rust-based extensions, you can rebuild them without reinstalling:
  1. Open the Extensions view
  2. Find your dev extension (marked with <> indicator)
  3. Click the Rebuild button
This recompiles the extension and hot-reloads it.

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Installing Specific Extension Versions

Sometimes you need to install a specific version of an extension (e.g., for compatibility or testing).
1

Find the extension

In the Extensions view, locate the extension you want
2

Open the extension menu

Click the three-dot menu (•••) on the extension card
3

Select Install Another Version

Choose “Install Another Version…” from the menu
4

Choose a version

A list of available versions will appear. Select the version you want to install.
Installing an older version may cause compatibility issues if the extension API has changed.

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Auto-Installing Extensions

Glass can automatically install certain extensions on first launch to provide essential language support out-of-the-box.

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Configuring Auto-Install

In your settings (settings.json): 
{
  "extensions": {
    "auto_install_extensions": {
      "html": true,
      "graphql": true,
      "python": true,
      "rust": true,
      "typescript": true
    }
  }
}
Extensions listed here will be automatically installed if:
  • They’re not already installed
  • Auto-install is enabled for that extension
  • It’s the user’s first launch or the setting was just added

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Disabling Auto-Install

To prevent an extension from auto-installing: 
{
  "extensions": {
    "auto_install_extensions": {
      "unwanted-extension": false
    }
  }
}

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Troubleshooting Installation Issues

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Extension Won’t Install

Check compatibility: Ensure the extension supports your version of Glass. Look for:
  • Schema version compatibility
  • WASM API version requirements
Check network: Installation requires internet access to download extensions from the registry. Check logs: Open the Glass log to see detailed error messages: 
View > Developer > Show Logs

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Extension Doesn’t Appear After Installation

Restart Glass: Some extensions may require a restart, though most load immediately. Check the extension index: Glass maintains an index at ~/.config/glass/extensions/index.json. If this is corrupted, run: 
Extensions: Reload Extensions

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Dev Extension Won’t Compile

Check Rust toolchain: Rust-based extensions require the Rust compiler. Ensure you have: 
rustc --version
cargo --version
Check manifest: Verify your extension.toml is valid: 
schema_version = 1  # Must be 1 for current extensions

[lib]
kind = "Rust"  # Required for Rust extensions
Check build errors: The error message will show compilation errors. Fix any Rust compiler errors in your code.

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Extension Security

Glass takes extension security seriously:
  • Sandboxing: Extensions run in WebAssembly sandboxes with limited system access
  • Capabilities: Extensions must declare required capabilities in their manifest
  • Verification: Published extensions are verified before installation
  • Source available: All published extensions have public repositories
Development extensions bypass some security checks. Only install dev extensions from sources you trust.

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Next Steps

Managing Extensions

Learn how to update, configure, and uninstall extensions

Building Extensions

Create your own extensions for Glass

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