Deprecated · Sampling Trace Conditioning

Sampling Trace Conditioning is the probe that sits on a CONDITIONING wire - the bundle of prompt embeddings, pooled vectors, and metadata that flows from Text Encode into your sampler. It records a numeric summary of the conditioning tensors and their metadata keys, then passes the conditioning through completely unchanged. No modification, no resampling, no touch.

Here's why that's useful, and it's more interesting than it sounds. CONDITIONING is where ControlNet and other advanced tools attach their payloads: a conditioning object carries not just the text embeddings but a dict of extra metadata that nodes like ControlNet Apply stuff into it. If something downstream is silently ignoring your ControlNet or mangling the embeddings, the smoking gun is usually in that metadata or in the tensor shape. This probe lists the metadata keys and summarizes the tensors (capped at 65,536 samples to keep it cheap), so you can see at a glance whether a custom node added or dropped something on the wire.

It's part of the pack's hidden probes family - deprecated and hidden from normal search in 0.4.0, kept for saved-workflow compatibility and internal diagnostics. Like its siblings, it does not start sampling trace capture on its own.

Inputs and outputs

• conditioning (required, CONDITIONING) - the branch to inspect.
• label (optional, STRING) - a name for the probe in the panel.
• trace_session (optional, TRACE_SESSION) - connect one to persist the summary into a run's evidence; otherwise the probe just emits a live event.
• Output: conditioning, unchanged.

Install

git clone https://github.com/ILcrowe/ComfyUI-SamplingTrace-Inspector.git ComfyUI/custom_nodes/ComfyUI-SamplingTrace-Inspector

or ComfyUI Manager → "Sampling Trace", restart. No dependencies beyond ComfyUI's own Python environment.

Where people get burned

• Hidden from search. Deprecated by design - old saved workflows load it, new graphs are steered to the one-node setup.
• Expecting it to trace. Probes don't start sampling trace; they record and pass through.
• Missing trace_session. Live event only, not stored history, unless you connect it.

Realistic verdict: if you're deep in ControlNet debugging on an old workflow, seeing the conditioning metadata is the one probe in this family with genuine "aha" potential. Everyone else can skip it.