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Watch a directory or file for changes and automatically recompile whenever CSS files are modified. Ideal for development workflows.

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Usage

rbx-css watch <path> [options]

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Arguments

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path
string
required
Directory or file to watch. If a directory is provided, all CSS files within it are monitored.

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Options

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-o, --output
string
Output file path. The format is automatically inferred from the file extension (.luau or .rbxmx).Default: Outputs to stdout on each change
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--name
string
default:"StyleSheet"
Name of the generated StyleSheet instance.
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--format
string
Explicitly set the output format. Valid values are luau or rbxmx.Default: Inferred from --output extension (defaults to luau if not specified)
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--warn
string
default:"all"
Warning level for unsupported CSS features. Valid values:
  • all - Show all warnings
  • unsupported - Show only unsupported feature warnings
  • none - Suppress all warnings
Watch mode does not support --strict mode. Warnings are always non-fatal to avoid disrupting your development workflow.

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Examples

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Watch a directory

rbx-css watch src/styles -o StyleSheet.luau
Monitors all CSS files in src/styles/ and recompiles to StyleSheet.luau on any change.

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Watch a single file

rbx-css watch styles.css -o out/StyleSheet.luau

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Watch with custom name

rbx-css watch src/styles -o CoreSheet.luau --name "CoreSheet"

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Watch and output to RBXMX

rbx-css watch src/styles -o styles.rbxmx

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Behavior

  • The watch process runs continuously until manually stopped (Ctrl+C)
  • Compilation errors are printed to stderr but do not stop the watch process
  • Each successful compilation prints: Compiled -> <output-path>
  • When watching a directory, all .css files are included

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Integration with Rojo

Watch mode pairs perfectly with Rojo’s live sync: 
# Terminal 1: Watch CSS files
rbx-css watch src/styles -o out/StyleSheet.luau

# Terminal 2: Run Rojo
rojo serve
Changes to your CSS files will automatically:
  1. Trigger rbx-css to recompile the StyleSheet
  2. Trigger Rojo to sync the updated file to Studio

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Example output

$ rbx-css watch src/styles -o StyleSheet.luau
Compiled -> StyleSheet.luau
# ... (watching for changes)
Compiled -> StyleSheet.luau
Compiled -> StyleSheet.luau

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Stopping the watcher

Press Ctrl+C to stop the watch process.

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