Configuring Codespaces for your project

About default codespace configurations

You can create a default codespace configuration for your repository that determines the environment of every new codespace anyone creates for that repository. The configuration defines a development container that can include frameworks, tools, extensions, and port forwarding.

If you don't define a configuration in your repository, GitHub creates a codespace with a base Linux image. The base Linux image includes tools for Node.js, JavaScript, TypeScript, Python, C++, Java, C#, .NET Core, PHP, and PowerShell. For more information about the base Linux image, see the microsoft/vscode-dev-containers repository.

You can also personalize aspects of the codespace environment for any codespace that your account creates. Personalization can include shell preferences and additional tools. Your dotfiles personalization is applied before a repository's default codespace configuration. For more information, see "Personalizing Codespaces for your account."

You can create a default codespace configuration using a pre-built container configuration for your project type, or you can create a custom configuration specific to your project's needs.

Codespaces uses settings contained in a configuration file named devcontainer.json. This file can be located in the root of the repository or in a folder called .devcontainer. If the file is located in the root of the repository, the filename must begin with a period: .devcontainer.json.

You can use your devcontainer.json to set default settings for the entire codespace environment, including the Visual Studio Code editor, but you can also set editor-specific settings in a file named .vscode/settings.json.

Changes to a repository's codespace configuration apply only to every new codespace and do not affect any existing codespace.

Using a pre-built container configuration

You can use any pre-built container configuration for Visual Studio Code that is available in the vscode-dev-containers repository. Pre-built container definitions include a common configuration for a particular project type, and can help you quickly get started with a configuration that already has the appropriate container options, Visual Studio Code settings, and Visual Studio Code extensions that should be installed.

1. Clone or download the vscode-dev-containers repository.
2. In the vscode-dev-containers repository, navigate to the containers folder, then choose a container configuration for your project's needs. We'll use the Node.js & JavaScript container configuration as an example.
3. From the Node.js & JavaScript folder, copy the .devcontainer folder to the root of your project's repository.
4. Commit and push the new configuration to your project's repository on GitHub.

Each new codespace created from a branch which contains the .devcontainer folder will be configured according to the folder's contents. For more information, see "Creating a codespace."

Creating a custom codespace configuration

If none of the pre-built configurations meet your needs, you can create a custom configuration by adding a devcontainer.json file. This file can be located in the root of the repository or in a folder called .devcontainer. If the file is located in the root of the repository, the filename must begin with a period: .devcontainer.json.

In the file, you can use supported configuration keys to specify aspects of the codespace's environment, like which Visual Studio Code extensions will be installed.

When you configure editor settings for Visual Studio Code, there are three scopes available: Workspace, Remote [Codespaces], and User. If a setting is defined in multiple scopes, Workspace settings take priority, then Remote [Codespaces], then User.

You can define default editor settings for Visual Studio Code in two places.

• Editor settings defined in .vscode/settings.json are applied as Workspace-scoped settings in the codespace.
• Editor settings defined in the settings key in devcontainer.json are applied as Remote [Codespaces]-scoped settings in the codespace.

Supported codespace configuration keys

You can use configuration keys supported by Codespaces in devcontainer.json.

General settings

• name
• settings
• extensions
• forwardPorts
• devPort
• postCreateCommand

Docker, Dockerfile, or image settings

• image
• dockerFile
• context
• containerEnv
• remoteEnv
• containerUser
• remoteUser
• updateRemoteUserUID
• mounts
• workspaceMount
• workspaceFolder
• runArgs
• overrideCommand
• shutdownAction
• dockerComposeFile

For more information about the available settings for devcontainer.json, see devcontainer.json reference in the Visual Studio Code documentation.