Logic Nodes

The backbone of your flows. Logic nodes transform data, route messages, implement conditional branching, and control timing. Master these nodes to build powerful automations.

32 Nodes

3 Core

∞ Transforms

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function switch change delay filter sort batch

function

Core

Write custom JavaScript code to transform messages and implement complex logic.

Language JavaScript (ES2020+)

Context Node, flow, global

Async Full async/await

Outputs Up to 10 outputs

Configuration

{cfg.key} string JavaScript function body

{cfg.key} number Number of outputs (1-10)

{cfg.key} string Setup code (runs once)

{cfg.key} string Cleanup code (on redeploy)

Output Example

{node.details.output}

Use node.warn() and node.error() for debugging. Access flow context with flow.get/set().

switch

Core

Route messages to different outputs based on property values or expressions.

Conditions ==, !=, <, >, regex

Property Any msg or JSONata

Rules Up to 20 conditions

Otherwise Catch unmatched

Configuration

{cfg.key} string "msg.payload" or expression

{cfg.key} array Array of conditions

{cfg.key} boolean Check all or stop at first

{cfg.key} boolean Reassemble sequences

Output Example

{node.details.output}

Use "otherwise" rule to catch unmatched messages. JSONata enables complex routing.

change

Core

Set, change, delete, or move message properties without code.

Operations Set, change, delete, move

Targets msg, flow, global

Values String, number, JSON

Regex Search/replace support

Configuration

{cfg.key} array Array of change operations

{cfg.key} string "set" | "change" | "delete" | "move"

{cfg.key} string Target property path

{cfg.key} any New value or expression

Output Example

{node.details.output}

Prefer change nodes over function nodes for simple transformations.

delay

Delay messages or rate-limit throughput for controlled processing.

Modes Fixed, random, rate limit

Units Milliseconds to days

Queue Configurable size

Drop Option when full

Configuration

{cfg.key} string "delay" | "rate" | "queue"

{cfg.key} number Delay duration

{cfg.key} string "milliseconds" | "seconds"

{cfg.key} number Messages per time period

Output Example

{node.details.output}

Use rate-limit mode to prevent flooding APIs. Send msg.reset to clear the queue.

filter

Filter messages based on conditions, remove duplicates, or sample data.

Modes Block unless changed

Compare Value or deep equality

Deadband Ignore small changes

Property Filter on any prop

Configuration

{cfg.key} string "rbe" | "deadband" | "narrowband"

{cfg.key} string Property to monitor

{cfg.key} number Deadband threshold

{cfg.key} any Initial value state

Output Example

{node.details.output}

Great for reducing sensor noise. Use deadband for analog sensors.

sort

Sort message sequences by property value or custom comparison.

Sort by Property or expression

Order Ascending/descending

Sequence Respects msg sequences

Type Number, string, custom

Configuration

{cfg.key} string Property to sort by

{cfg.key} string "msg" | "jsonata"

{cfg.key} string "ascending" | "descending"

{cfg.key} boolean Treat as numbers

Output Example

{node.details.output}

Works with split node sequences. Use with join node to reassemble.

batch

Group messages into arrays for bulk processing and database inserts.

Modes Count, interval, concat

Count Group by msg count

Interval Group by time window

Overlap Sliding window support

Configuration

{cfg.key} string "count" | "interval" | "concat"

{cfg.key} number Messages per batch

{cfg.key} number Time window in seconds

{cfg.key} number Sliding window overlap

Output Example

{node.details.output}

Essential for efficient database writes. Reduces I/O by 10-100x.

Common Flow Patterns

Route by Type

Use switch → function to route messages by type, then process each with specialized logic.

Filter & Batch

Use filter → batch → database to filter valid readings, batch them, then bulk insert.

Transform & Delay

Use change → delay → output to transform format, rate-limit, then send notifications.

Aggregate Data

Use batch → function to collect readings, then calculate averages or totals.

More Logic Nodes

if

Conditional branching

function-node

Custom JavaScript code

exec

System command execution

python

Python script execution

template

Mustache template rendering

range

Scale/map numeric ranges

split

Split messages

join

Join message sequences

catch

Error handling

status

Monitor node status

complete

Completion triggers

set

Set/delete properties

link-in

Virtual wiring receiver

link-out

Virtual wiring sender

trigger

Delayed trigger patterns

rbe

Report by exception

comment

Flow annotation

base64

Base64 encode/decode

compress

Data compression

encrypt

AES encryption

hash

Cryptographic hashing

math

Mathematical operations

regex

Regular expressions

statistics

Statistical analysis

rate-limit

Rate limiting

json-parser

JSON parse/stringify

xml-parser

XML parse/stringify

csv-parser

CSV parse/stringify

yaml-parser

YAML parse/stringify

html

HTML CSS selectors

Continue Learning

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