Depending on your version of Maya, you may need a specific version of the script:

Open the Script Editor , create a Python tab , and enter: import tweenMachine tweenMachine.start() Use code with caution.

You can still find legacy versions via Justin Barrett’s official site or on platforms like Highend3D .

You can choose to apply the tween to all attributes or only those highlighted in the Channel Box . Modern Alternatives

If you are looking for more advanced features like live previews or color-coded keys, consider exploring:

Download the ZIP and extract the tweenMachine.py file and the icon.