1. Access the {% data variables.product.prodname_vscode_command_palette %} (<kbd>Shift</kbd>+<kbd>Command</kbd>+<kbd>P</kbd> / <kbd>Ctrl</kbd>+<kbd>Shift</kbd>+<kbd>P</kbd>), then start typing "dev container". Click **Codespaces: Configure Dev Container**.

   ![Screenshot of the Command Palette, filtered to show only the "Codespaces: Configure Dev Container" option.](/assets/images/help/codespaces/add-prebuilt-container-command.png)

1. Click **Start from scratch**.
1. In this example, the template repository from which you created the codespace already contains a dev container configuration, so a message is displayed telling you that the configuration file already exists. We're going to overwrite the existing configuration file, so click **Continue**.

1. Click **Show All Definitions**.

   ![Screenshot of the "Add Dev Container Configuration Files" menu with the dropdown showing various options, including "Show All Definitions."](/assets/images/help/codespaces/show-all-definitions.png)