Audio Passthrough

Audio Passthrough takes an audio input and hands back the exact same audio on its output. Nothing transformed, nothing inspected - it exists so an audio wire can be broken into readable segments, named, or forced into existence as a socket. It's part of the pack's family of twelve generated passthrough nodes (Image, Mask, Latent, CLIP, Model, Conditioning, Text, Int, Float, Bool, Audio, and more), all stamped out by the same loop in Any_Passthrough.py.

Here's the thing you should know before you wire it anywhere: it's a duplicate. The pack also ships a hand-written wcx_AudioPass in Audio_Pass.py with the same category (Practical-Tools/Passthrough), the same AUDIO-in/AUDIO-out contract, and the same behavior. They are functionally interchangeable - this one is the generated version, Audio Pass is the hand-rolled one, and neither is better. The only practical advice is to pick one and be consistent, because when you share a workflow, "which audio passthrough is in this graph" should not be a question anyone has to answer.

Why bother with an audio passthrough at all? Two honest uses, both straight from the node-plumbing playbook:

• Organization. Video workflows that carry sound drag an audio wire halfway across the canvas. A passthrough turns one long line into readable segments, the same job a Reroute does for any type.
• Forcing an optional input. The input is forceInput, so it behaves like a socket you must wire - useful when a downstream node only exposes an optional audio input and you want the connection guaranteed rather than skipped.

The mechanism is a pure hand-off: whatever comes in goes out, and None in means None out. It's thin on purpose - a passthrough with hidden logic would be a bug. The one ecosystem note: audio is a newer, bolted-on corner of ComfyUI (per the KB's audio-generation doc), so nodes that carry AUDIO around are still thinner on the ground than image plumbing - which is precisely why this trivial node is handy to have.

Install is pack standard: ComfyUI Manager → search ComfyUI-Practical-Tools → install → restart, or git clone https://github.com/wenchengxiang/ComfyUI-Practical-Tools into ComfyUI/custom_nodes. No dependencies, no models. Output None means nothing was wired in - end of troubleshooting.