Remove Backend Data [NumberKey] (Inspire)

This is the cleanup node for Inspire's Backend Cache - the NumberKey flavor. If you've been stashing data in the backend cache and want to drop an entry, this removes the one stored under a given numeric key. The NumberKey variant exists specifically for automation: when you're generating keys programmatically in a loop, integers are easier to iterate than strings.

Backend Cache, if you haven't met it: Inspire lets you park arbitrary data - a checkpoint, a latent, an intermediate result - in memory under a key and reuse it later, even across workflows in the same ComfyUI session. Cache nodes put things in, Retrieve nodes pull them out, and Remove nodes clear them when you're done. This is a Remove node keyed by number.

How it works

You give it a number, it deletes the cache entry under that key. One nuance the pack calls out and it's worth internalizing: this only removes the data from Inspire's own cache bookkeeping. If the same object is still referenced elsewhere - held by another node, still in use - it won't actually be freed from memory. So think of it as "release my hold on this cache slot," not a guaranteed memory purge.

The other useful detail is execution order. Cache cleanup is timing-sensitive - you don't want to delete something before the node that reads it has run. That's what signal_opt is for.

The inputs and outputs

• key (INT) - the numeric cache key to remove.
• signal_opt (optional, wildcard) - an ordering input. It carries no data meaning; it just lets you force this node to run after something else by wiring that something's output into it. The node runs fine without it, but it's how you guarantee "delete only after the consumer is done."
• Output is a signal (wildcard) you can chain onward to sequence further nodes. This is an output node, so it executes as an endpoint in the graph.

How to install it

ComfyUI Manager: Install Custom Nodes → search ComfyUI Inspire Pack → install → restart. Or:

cd ComfyUI/custom_nodes
git clone https://github.com/ltdrdata/ComfyUI-Inspire-Pack

Then restart. The pack is Dr.Lt.Data's - clean, well-maintained, no model downloads for this node.

Common issues

The classic mistake is expecting this to reclaim VRAM/RAM on its own. It removes the cache entry, but if anything else still references the object, memory isn't freed - the docs are explicit about that. Second, ordering bugs: if you delete before the retrieving node has actually run, you'll get a cache miss downstream. Use signal_opt to pin this node after the consumer. And make sure the numeric key matches exactly what you cached under - a wrong number just removes nothing (or the wrong entry) with no loud complaint. If you're keying with strings instead of numbers, you want the plain Remove Backend Data node, not this NumberKey one.