Save for Next Time

ComfyUI has a genuinely awkward gap: it's great at one run, but there's no built-in way to say "take what I just made, and start the next run from it." You end up saving a frame, remembering the filename, then hand-loading it into the next workflow. Save for Next Time closes that gap - it stashes whatever data you wire into it under a named slot, and its sibling Take from Last Time reads it back on a later queue run.

The use case is the "iterate on my last render" loop: save the last frame, the prompt that made it, and maybe the latent, then have the next run pick all of them up without you touching a single load node.

How it works

You pick a slot_name (the folder under output/for_next_time/<slot_name>/), connect any mix of inputs, and everything that arrives together becomes one entry. Connect as many or as few as you like - a single entry holds whatever was wired that run:

• image → saved as PNG (one file per batch frame)
• mask → grayscale PNG
• text → UTF-8 text
• audio → FLAC
• video → MP4 (copied without re-encoding when the source already matches)
• latent → a .latent safetensors file
• note → a label stored in the entry's meta.json, purely for your own bookkeeping

max_entries keeps the newest N saves (default 10) and deletes the rest. Keep it low - the tooltip warns that each entry holds a full copy of the video, so a big max_entries fills your disk in a hurry.

Two details show real care. Entries are published by an atomic folder rename, so a run killed mid-save never leaves a half-written entry. And if you rename an entry folder by hand to drop the 00000001- timestamp prefix, it becomes a permanent pin - still reachable by name, never pruned.

The design quirk that will surprise you

This node has no outputs, on purpose. The reason is a subtle ComfyUI cache interaction: the node has to run every queue (it's NOT_IDEMPOTENT), and a node that runs every time poisons the cache of everything downstream of it. Give it outputs and NaN-style always-run behavior, and you'd force the sampler and everything else to re-run every queue. So instead, you wire your data to this node and to whatever else needs it - it's a tap, not a sink.

Wiring and caveats

The pair is designed for consecutive runs. Using Save and Take on the same slot in the same prompt isn't supported - ComfyUI doesn't order two unconnected nodes, so Take's cache check can run before Save does. If that trips you up, split it into two runs.

Where people get burned: forgetting the slot_name has to match exactly between Save and Take (letters, digits, spaces, and . - _ only), and forgetting that max_entries applies to the slot, so an old pinned name you thought you deleted is still sitting there. Both are one-look fixes.

Install

It's one of ~69 nodes in TrentNodes:

# ComfyUI Manager: search "Trent Nodes"

# or:
cd ComfyUI/custom_nodes
git clone https://github.com/TrentHunter82/TrentNodes.git
cd TrentNodes && pip install -r requirements.txt

No extra dependencies for this pair. It's the kind of node that reads as "why would I need that" until the first time you finish a render, queue the next run, and watch your last frame just appear where it belongs.