Dynamic configuration {#dynamic-configuration}

There are certain scenarios where you might need to dynamically configure your project at generation time. For example, you might want to change the name of the app, the bundle identifier, or the deployment target based on the environment where the project is being generated. Tuist supports that via environment variables, which can be accessed from the manifest files.

Configuration through environment variables {#configuration-through-environment-variables}

Tuist allows passing configuration through environment variables that can be accessed from the manifest files. For example:

TUIST_APP_NAME=MyApp tuist generate

If you want to pass multiple environment variables just separate them with a space. For example:

TUIST_APP_NAME=MyApp TUIST_APP_LOCALE=pl tuist generate

Reading the environment variables from manifests {#reading-the-environment-variables-from-manifests}

Variables can be accessed using the <LocalizedLink href="/references/project-description/enums/environment">Environment</LocalizedLink> type. Any variables following the convention TUIST_XXX defined in the environment or passed to Tuist when running commands will be accessible using the Environment type. The following example shows how we access the TUIST_APP_NAME variable:

func appName() -> String {
    if case let .string(environmentAppName) = Environment.appName {
        return environmentAppName
    } else {
        return "MyApp"
    }
}

Accessing variables returns an instance of type Environment.Value? which can take any of the following values:

You can also retrieve the string or boolean Environment variable using either of the helper methods defined below, these methods require a default value to be passed to ensure the user gets consistent results each time. This avoids the need to define the function appName() defined above.

::: code-group

Environment.appName.getString(default: "TuistServer")

Environment.isCI.getBoolean(default: false)

:::