Which tool allows users to manipulate audio file fades?

The Fade Tool is specifically designed for manipulating fades within audio files in Logic Pro. Fades are used to create smooth transitions at the beginning and end of audio clips, which can help prevent abrupt starts or stops that may lead to clicks or pops in the sound. With the Fade Tool, users can click and drag on an audio region to create either fade-ins or fade-outs, adjusting the curve shape to achieve the desired effect.

The other tools mentioned have distinct functions: the Flex Tool is used for time-stretching and pitch-shifting audio, allowing for more complex adjustments to audio clips. The Audio File Editor allows for detailed editing of audio files, such as trimming and processing, but does not specifically focus on fade manipulation. The Automation Tool is used to control various parameters over time in a session, including volume, panning, and effects, rather than directly applying fades to audio regions.