comfy-flow-control

ComfyUI flow control

Routing, switching, broadcast, bundling, looping, gating. Where does the signal go once the decision is made.

Six packs on this install contribute flow-control primitives. Each has overlapping options and pack-specific quirks — the goal of this skill is to pick the right one in one decision, not browse a dropdown.

When to Use This Skill

Use this skill when...	Use instead when...
Wiring how a signal routes, switches, broadcasts, loops, or is gated	Forming the predicate that drives the route -> comfy-conditionals
Picking a switch / index-switch / broadcast node	Debugging or inspecting a routed value -> comfy-debug-preview

Sources of truth

• custom_nodes/rgthree-comfy/__init__.py — context bundles, Any Switch, Power Lora Loader, fast groups muter (frontend-only)
• custom_nodes/cg-use-everywhere/__init__.py — broadcast "Anything Everywhere" sentinels
• custom_nodes/ComfyUI-Crystools/crystools/nodes_switch.py — type-typed CSwitchBoolean* family
• custom_nodes/comfyui-impact-pack/modules/impact/special_samplers.py and core.py — ImpactSwitch (GeneralSwitch/GeneralInversedSwitch), ImpactConditionalBranch, ExecutionOrderController
• custom_nodes/comfyui-easy-use/py/nodes/logic.py and flow.py — easy switches, pipes, forLoop, whileLoop, blocker
• ComfyUI core — built-in ComfySwitchNode (boolean toggle between two same-type inputs)

Pick-a-switch decision

You have…	Selector	Best node	Why
2 IMAGE inputs, BOOLEAN selector	bool	easy imageSwitch or Crystools CSwitchBooleanImage	Lazy: only the chosen branch runs
2 ANY inputs, BOOLEAN selector	bool	Crystools CSwitchBooleanAny	Lazy; cleanest signature
2 STRING inputs, BOOLEAN selector	bool	easy textSwitch or Crystools CSwitchBooleanString	Both lazy
2 CONDITIONING inputs, BOOLEAN	bool	Crystools CSwitchBooleanConditioning	Lazy; native CONDITIONING type
2 LATENT / MASK inputs, BOOLEAN	bool	Crystools CSwitchBooleanLatent / CSwitchBooleanMask	Lazy; typed
N ANY inputs, INT selector (3-20)	index	easy anythingIndexSwitch (up to 20)	Only easy-use scales past 2 inputs
N IMAGE / TEXT / CONDITIONING, INT	index	easy imageIndexSwitch / easy textIndexSwitch / easy conditioningIndexSwitch	Typed N-way
K ANY inputs, "first non-None wins"	any	rgthree Any Switch	Pick the first connected/non-empty input
1 ANY input → 2 ANY outputs (demux)	bool	Crystools CSwitchFromAny	Unique: output-side mux. Bool routes the one input to one of two outputs
2 BOOLEAN inputs that disagree	logic	easy compare or ImpactCompare then a switch above	Predicate formation lives in comfy-conditionals
Toggle entire LoRA stack on/off	bool	rgthree Power Lora Loader with toggles per row	Single node holds the stack + per-LoRA enable/strength
Mute/bypass a whole group of nodes	mouse	rgthree fast groups muter (frontend)	Right-click group → Mute / Bypass. No node needed

Input-side vs output-side mux

• Input-side mux (the standard pattern): N inputs → 1 output. The switch decides which input to forward. The bool/index selector reads before the upstream graph evaluates, so unselected branches can often be skipped (see lazy-vs-eager below).
• Output-side mux (Crystools CSwitchFromAny only): 1 input → 2 outputs. The bool picks which output port receives the value; the other port emits None / a default. Use this when one upstream feeds two divergent downstream paths and you want to send it to only one at a time.

Lazy vs eager evaluation

Lazy switches mark unselected branches as "do not evaluate", so the upstream chain feeding the discarded branch is skipped entirely. Saves GPU and time. Eager switches force every upstream branch to compute even if its output gets thrown away.

Lazy (skip unselected upstream)	Eager (run all branches always)
easy ifElse, easy imageSwitch, easy textSwitch, easy anythingIndexSwitch (and the typed *IndexSwitch siblings), easy blocker (downstream blocker)	ImpactSwitch / GeneralSwitch (data routing only)
All CSwitchBoolean* (Crystools)	CSwitchFromAny (must compute input before routing)
ImpactConditionalBranch, ImpactConditionalBranchSelMode	rgthree Any Switch (selects after upstream resolves)

When the unselected branch is cheap (a constant or a small VAEDecode), the difference is invisible. When it's a sampler chain, lazy switches save tens of seconds per queue.

Broadcast routing — cg-use-everywhere

The Anything Everywhere family doesn't have output ports. You wire a value (model / clip / vae / seed / conditioning / anything) into the node, and it acts as an invisible producer: any unconnected input slot of the matching type elsewhere in the graph receives the value automatically.

Node	Use when
Anything Everywhere	One MODEL or VAE is reused by 6 nodes scattered across the graph — declare once, skip 6 reroute wires
Anything Somewhere	Regex-filtered: broadcasts only to inputs whose socket name matches the regex you set on the broadcaster
Anything Everywhere Triplet	Positive + negative + latent triplet bundle (the SDXL/Flux conditioning trio)
Seed Everywhere	Deprecated; the frontend auto-rewrites to a regular Anything Everywhere connected to INT

Silent-failure mode: if two broadcasters carry compatible types and both could match an empty socket, one of them wins (depends on node id ordering) and the other is silently ignored. Color the broadcasters in the UI so the routing is visible — they're invisible by design and hard to debug otherwise. When debugging, replace with explicit reroutes to see exactly where each value lands.

Use broadcast for scalars and constants (seed, model, vae, a shared prompt). Avoid for transient intermediate values whose meaning shifts as the graph runs — explicit wires there make the workflow more legible.

Context vs pipe bundles

Both rgthree's Context and easy-use's pipeIn/pipeOut carry a multi-typed bundle on a single wire. They are not interchangeable.

	rgthree Context	easy-use pipe
Wire type	RGTHREE_CONTEXT (custom)	PIPE_LINE (custom)
Field access	Named (model / clip / vae / positive / negative / latent / image / seed)	Positional (model, pos, neg, latent, vae, clip, image, seed)
Override / edit mid-graph	Context Merge / Context Merge Big	pipeEdit
Unpack	Context Switch selects between multiple full contexts; individual fields auto-emerge from the Context node's right side	pipeOut emits all 8 slots; or downstream nodes consume PIPE_LINE directly
Bridge between	Convert manually: unpack with Context outputs → repack with pipeIn (and vice-versa)	Same, reverse
Best for	Sharing a stable model/clip/vae across many subgraphs	easy-use's own ecosystem (its samplers and pre-samplers expect PIPE_LINE)

Mixing the two in one workflow is allowed but every cross-bridge is a manual repack. Pick one bundle convention per workflow.

Loops

Easy-use ships the only general-purpose loop primitives in this install. Use sparingly — ComfyUI's execution model wasn't designed for iteration, and loops expand at prompt-queue time to a sequence of copied subgraph nodes (so an N=50 loop is N=50 sampler instances in the graph, not one node looping).

Loop	Setup
easy forLoopStart → body → easy forLoopEnd	total count (INT), values_1..N carry state through iterations
easy whileLoopStart → body → easy whileLoopEnd	condition (BOOLEAN) checked after each iteration; emits FLOW_CONTROL token + state

Best practice:

• Keep loop bodies short. Each iteration replicates the entire subgraph in the queue, so 30 iterations × 50 nodes ≈ 1500-node queue.
• Always have an exit predicate. whileLoopEnd with no terminating condition will hang the queue forever.
• The state-carry slots (values_*) are how you accumulate — write to them at the end, read at the start.
• For per-image batch iteration, prefer ComfyUI's native batch semantics (let the sampler process a batch) over a loop. Loops are for iteration where each round depends on the previous round's output.

Execution gating

Primitive	What it does
easy blocker	Pass-through; if continue=False returns an ExecutionBlocker sentinel. Any downstream node touching the sentinel is silently skipped.
ImpactConditionalStopIteration	Inside an Impact iterator (detector → detailer loop), halts the loop when its BOOLEAN input is True.
ImpactExecutionOrderController	Pins a side-effect node (SaveImage, log, webhook) to run before / after a designated other node. Used when ComfyUI's free reordering picks the wrong sequence.

ExecutionBlocker is the canonical "kill this path" primitive in ComfyUI — see comfy-conditionals for predicate formation and detailed semantics (Preview Bridge consumes the sentinel silently; SaveImage downstream is the abort target).

Recipes

Toggleable LoRA stack with bypass

You have 3–8 LoRAs stacked into a chain. You want each one individually toggleable, with a master "all off" too.

UNETLoader ─┐
            │
            ▼
rgthree Power Lora Loader  ← per-row: enabled (bool), name, strength
            │
            ▼
ModelSamplingAuraFlow (or whatever)

• One node holds the stack. UI per-row toggle + strength.
• Group the loader + downstream sampler nodes; right-click → Mute Group to bypass the whole branch when prototyping.
• To make a single LoRA toggleable as a separate node, wrap with Crystools CSwitchBooleanAny: bool=on → goes through LoraLoaderModelOnly, bool=off → bypasses straight to the next stage.

Optional upscale pass with lazy switch

User sometimes wants a 2× upscale, sometimes doesn't. Without lazy evaluation, the upscale chain (model loader + KSampler + VAEDecode) runs even when discarded.

                              ┌── on_true: UpscaleModelLoader → Sampler → VAEDecode ──┐
SaveImage upstream ────────── ┤                                                       ├── SaveImage
                              └── on_false: passthrough ─────────────────────────────┘
                                 ▲
                                 │
                              Crystools CSwitchBooleanImage (lazy)

• The Crystools switch is lazy → when bool=False, the entire upscale chain is skipped, not just discarded.
• Bool can come from a PrimitiveBoolean, a RgthreeContext field, or an easy compare predicate.

Migrating a workflow off broadcast wires for review

When sharing a workflow that uses Anything Everywhere, the rest of the graph has unconnected input sockets that "look" wrong but work fine because of the broadcaster. For readability when sending the workflow to someone:

1. Right-click Anything Everywhere → "Show connections" (frontend flag in the rgthree side panel) — renders dashed lines.
2. Manually wire what the broadcaster was implicitly doing.
3. Delete the broadcaster node.

Reverse the process when receiving a wired workflow you want to clean up.

Gotchas

• ComfySwitchNode (core) is widget-overridden by an input. When you wire a BOOLEAN into the switch slot of ComfySwitchNode, the node's own widget value is ignored — the connected input wins. This bites you when the widget shows False but a connected PrimitiveBoolean(True) is in effect.
• Any Switch (rgthree) is eager — it evaluates all upstream inputs before picking the first non-None. Don't use it as a performance optimizer; use a typed CSwitchBoolean* for laziness.
• Preview Bridge swallows ExecutionBlocker: if you tee a path through Preview Bridge to inspect it, and the path is blocked, the Preview shows nothing and the downstream abort doesn't propagate through the bridge. Use FastPreview (comfyui-kjnodes) downstream of a Preview Bridge when blockers may appear, or wire previews off branches that can't be blocked.
• ImpactConditionalBranch.cond is BOOLEAN, not INT/FLOAT. SimpleMathCondition (essentials) returns FLOAT — convert with a comparator before feeding the branch.
• Context Big silently drops mismatched slots. If you wire an IMAGE to a Context Big.latent slot the wire is ignored at evaluation. Hover the Context outputs to check what's actually populated.
• Easy-use loops expand at queue-time, not runtime. A loop of 50 iterations becomes 50 copies of the body inside the queue's prompt graph. Very large loops can OOM the frontend (browser) before even reaching the backend.

Cross-refs

• comfy-conditionals — forming the boolean / index that feeds these switches. Predicates, comparisons, null checks, ExecutionBlocker patterns.
• comfy-prompting — Power Lora Loader plays nicely with LoRA trigger-word autoload nodes; see the cross-ref there for the full recipe.
• comfy-debug-preview — Preview Bridge details, FastPreview as the blocker-aware alternative.
• comfy-math-strings — primitive sources (PrimitiveBoolean, INT/FLOAT constants, sliders) that drive these switches.

Things this skill does NOT cover

• Predicate formation — how to build the boolean that feeds a switch. → comfy-conditionals.
• Reroute nodes for visual cleanup — those are frontend-only and don't affect execution; covered by comfy-workflow-layout and rgthree's UI affordances.
• Sampler / model routing (KSampler vs DPMPP vs Euler, model loader switching) — that's model-family work; see wan, z-image, hidream-o1 skills.
• Subgraph composition — packaging part of a workflow into a reusable subgraph. That's a project CLAUDE.md topic under "Editing workflow JSON".