listAppendNode.md

List Append (listAppendNode)

Category: Lists

Intended behavior

Collects values into a list — each Append trigger pushes the current Value onto the end.

Inputs

ID	Label	Type	Unwired default
value	Value	any	0
inTrigger	Append	trigger	undefined
resetTrigger	Reset	trigger	undefined

Outputs

ID	Label	Type	Default
outTrigger	Out	trigger	undefined
list	List	any	undefined
length	Length	number	undefined

Configuration defaults

{
  "items": []
}

Observed frontend behavior

This calls the production passive computation with the declared input/config defaults. Cached state, trigger execution and project wiring are separate.

{
  "kind": "passive-default-probe",
  "outputs": {
    "list": [],
    "length": 0
  }
}

Observed backend behavior

Offline production passive computation with the same declared defaults; no device or model service is invoked.

{
  "kind": "passive-default-probe",
  "outputs": {
    "list": [],
    "length": 0
  }
}

Current frontend implementation

Extracted production branches; helper calls and project execution context are defined in the referenced modules.

src/lib/list-node-compute.ts:51

listAppendNode: (_inputs, config) => {
    const items = toList(config.items);
    return { list: items, length: items.length };
  }

src/lib/extra-trigger-ops.ts:41

listAppendNode: (inputs, config, port) => {
    const items = port === "resetTrigger" ? [] : [...toList(config.items), inputs.value];
    return { nextTriggerPort: "outTrigger", updatedConfig: { ...config, items } };
  }

Implementation references

• src/lib/list-node-compute.ts:51
• src/lib/extra-trigger-ops.ts:41
• backend/engine/lists.py:143
• backend/engine/trigger_state.py:39

Verification limits

• Default passive probe is an observation, not proof of all configurations, trigger behavior, or correctness. See ../NODE_RUNTIME_AUDIT.md and ../AUDIT_VALIDATION.md for test evidence.
• Trigger inputs schedule actions; passive evaluation alone does not execute those actions. Wire a trigger source and test the full chain.

Source fingerprint: 7e9d192bd3a559a7c50253919867601ef02c311d61e859f7afb4cadcfa508430. Rebuild with npm run docs:index.