Delete Key-Value Pairs

Use this node to strip internal or sensitive fields from a message before forwarding it to external systems, or to clean up temporary keys added by upstream enrichment nodes. Java regular expressions let you remove entire groups of keys (e.g., all temp_* fields) with a single pattern.

Configuration

Delete key-values from — required. Where to delete keys:
- Message — deletes from message data.
- Metadata — deletes from message metadata.
Keys — a set of key names or Java regular expression patterns. Keys not present in the source are silently ignored.

Message processing algorithm

Determine the deletion target (message data or metadata).
For each source key, check whether it matches any configured pattern.
Remove all matching key–value pairs.
If at least one key was removed, forward the updated message via Success. Otherwise forward unchanged.
On unexpected error, route via Failure.

Output connections

Connection	Condition
`Success`	Processing completed (including when no keys were deleted).
`Failure`	An unexpected error occurred.

Examples

Example 1 — Delete specific keys from data

{ "deleteFrom": "DATA", "keys": ["internal_id", "deviceName"] }

Incoming data: { "temperature": 25.4, "humidity": 62, "internal_id": "xyz-123", "deviceName": "Sensor-A1" }

Outgoing data: { "temperature": 25.4, "humidity": 62 }

Example 2 — Delete keys from metadata

{ "deleteFrom": "METADATA", "keys": ["rssi", "snr"] }

Incoming metadata: { "deviceType": "Thermostat", "location": "Floor 1", "rssi": "-56", "snr": "12.1" }

Outgoing metadata: { "deviceType": "Thermostat", "location": "Floor 1" }

Example 3 — Regex pattern deletes multiple keys

{ "deleteFrom": "DATA", "keys": ["temp_.*"] }

Incoming data: { "temp_main": 33.1, "humidity": 45, "pressure": 1012, "temp_ambient": 21.5 }

Outgoing data: { "humidity": 45, "pressure": 1012 } — both temp_* keys removed.

Example 4 — No matching keys — message passes unchanged

{ "deleteFrom": "DATA", "keys": ["pressure"] }

Incoming data: { "temperature": 22.5, "humidity": 55 } — pressure doesn’t exist.

Outgoing data: unchanged. Routes via Success.

JSON schema

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "TbDeleteKeysNodeConfiguration",
  "type": "object",
  "required": ["deleteFrom", "keys"],
  "additionalProperties": false,
  "properties": {
    "deleteFrom": {
      "type": "string",
      "enum": ["DATA", "METADATA"],
      "description": "Where to delete: DATA = message data, METADATA = message metadata."
    },
    "keys": {
      "type": "array",
      "items": { "type": "string" },
      "description": "Key names or Java regex patterns to delete."
    }
  }
}