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Flux Tail

Subscribe to a SolarFlux topic and display received messages.

Bug

This command might print some scary looking WARNING messages to standard error when it starts up. These can be ignored by redirecting standard error, for example 2>/dev/null in macOS or Linux.

Usage

s10k flux tail [-G] [-prop=propName[,propName...]]...
                [-R=<maxPrecision>] [--client-id=<clientIdSuffix>]
                (
                    -t=filter
                    [[-node=<nodeId>] [-source=<sourceId>]]
                )
                [-mode=<displayMode>]

Options

Option Long Version Description
-G --csv-global-header display just one CSV header row, based either on the -prop values or the first message properties
-prop= --property= restrict the results to this property (or properties for multiple)
-R= --max-precision= maximum number of decimal digits to display, or -1 for no rounding; defaults to 3
--client-id a specific client ID to use, instead of a random default
-t= --topic= the MQTT topic filter to subscribe to (exclusive to -node and -source)
-node= --node-id= the node ID (or + wildcard) to show datum for (exclusive to -topic, requires -source)
-source= --source= the source ID topic pattern to show datum for (exclusive to -topic, requires -node)
-mode= --display-mode= the format to display the data as, one of CSV, JSON, or PRETTY; defaults to PRETTY; note that PRETTY is not suitable for large result sets

Output

All matching messages. To stop receiving messages type Ctrl+C on macOS or Linux.

Examples

Subscribe to all node 101 datum sources starting with con/, showing just the created, sourceId, watts, and wattHours properties. Note the --csv-global-header only applies to the CSV output:

s10k flux tail --node-id 101 --source-id con/\#  \
  --csv-global-header \
  --property created,sourceId,watts,wattHours

+--------------------------+----------+-------+-----------+
| created                  | sourceId | watts | wattHours |
+--------------------------+----------+-------+-----------+
| 2025-09-05T06:24:55.227Z | con/pcm  |  2408 |   8259102 |
+--------------------------+----------+-------+-----------+
+----------------------+----------+-------+-----------+
| created              | sourceId | watts | wattHours |
+----------------------+----------+-------+-----------+
| 2025-09-05T06:26:35Z | con/1    |  1252 |   8258876 |
+----------------------+----------+-------+-----------+

created,sourceId,watts,wattHours
2025-09-05T06:39:35Z,con/1,3087,8259410
2025-09-05T06:39:55.227Z,con/pcm,3270,8259700

{
    "ts" : "2025-09-05 06:40:25.732246Z",
    "body" : {
        "created" : "2025-09-05 06:40:25.227Z",
        "sourceId" : "con/pcm",
        "watts" : "2653",
        "wattHours" : "8259722"
    },
    "topic" : "user/123/node/101/datum/0/con/pcm"
}
{
    "ts" : "2025-09-05 06:40:35.511049Z",
    "body" : {
        "created" : "2025-09-05 06:40:35Z",
        "sourceId" : "con/1",
        "watts" : "3363",
        "wattHours" : "8259466"
    },
    "topic" : "user/123/node/101/datum/0/con/1"
}

Monitor OCPP inbound message events for charger:

s10k flux tail --display-mode JSON \
  --topic user/123/event/ocpp/message/received \
  |jq 'select(.body.data.cp == "chgr123") | .body.data'

{
    "cp": "chgr123",
    "messageId": "3ed43c9f-7fc2-4ed8-ac51-70e1987e8e80",
    "action": "MeterValues",
    "message": {
        "connectorId": 2,
        "transactionId": 257979,
        "meterValue": [
            {
                "timestamp": "2025-09-07T04:51:43.000+00:00",
                "sampledValue": [
                {
                    "value": "289314130",
                    "context": "Sample.Periodic",
                    "format": "Raw",
                    "measurand": "Energy.Active.Import.Register",
                    "location": "Outlet",
                    "unit": "Wh"
                }
                {
                    "value": "3498.0",
                    "context": "Sample.Periodic",
                    "measurand": "Power.Active.Import",
                    "location": "Outlet",
                    "unit": "W"
                }
                ]
            }
        ]
    }
}
{
    "cp": "chgr123",
    "messageId": "d8551a59-4cf5-4958-8487-ca2dedfcb21a",
    "action": "Heartbeat"
}