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Utility & debugging

Helper nodes for logging, inspecting data, and running commands and containers. In the palette they sit under Developer Tools. All of them have one input and one output port.

Log

What: Writes a log line and passes the data on unchanged.

The Log node's panel in the editor: the header with the node's icon and name, and its Settings tab.The Log node's panel in the editor: the header with the node's icon and name, and its Settings tab.

Configuration:

Field Notes
message The text to log. Supports expressions.
level debug, info (default), warn or error
prefix Default LOG
output console (default), file or both
filePath For file and both
passThrough Default on

Example:

message: Processed order {{ $trigger.payload.orderId }} for {{ $trigger.payload.customerName }}, tracking {{ $node["Create label"].output.trackingNumber }}
level:   info

Tip: To see everything an upstream node produced, log the whole output: {{ $node["HTTP Request"].output }}. Lists and objects are written as JSON.

Debug

What: Inspects data, profiles performance, traces execution, validates schemas and simulates errors.

Configuration: operation (required: inspect_data, performance_profile, trace_execution, validate_schema, simulate_error, log_debug, memory_analysis, benchmark), level (trace, debug default, info, warn, error), config.

Use when: Testing how the rest of a workflow behaves when a step fails (simulate_error), or checking the shape of data mid-flow.

Terminal

What: Runs a shell command and returns its output.

The Terminal node's panel in the editor: the header with the node's icon and name, and its Settings tab.The Terminal node's panel in the editor: the header with the node's icon and name, and its Settings tab.

Configuration:

Field Notes
command Required. The command to run.
shell bash, zsh or sh
workingDirectory Where to run it
timeout Milliseconds. Default 30 000.
environment Environment variables for the command. Nothing else is inherited.
continueOnError Keep the run going when the command fails, like the Continue Anyway error mode. Default off.

Output: stdout, stderr and exitCode.

Notes:

  • Commands run in the same isolated environment as the Code node, with no access to your credentials.
  • Expressions in command are passed to the shell as environment variables, not pasted into the command text, so data can't inject extra commands.

Docker

What: Builds, runs, tags, pulls and pushes container images, and reads container logs.

The Docker node's panel in the editor: the header with the node's icon and name, and its Settings tab.The Docker node's panel in the editor: the header with the node's icon and name, and its Settings tab.

Configuration: operation (required: build, run, push, tag, pull, logs, inspect, remove, listImages, listContainers, version), plus the fields each operation needs: image, dockerfile (default Dockerfile), buildArgs, cmd, env, container, repo, tag, registry credentials, and timeout (default 30 minutes).

The Docker node works only where your Flero administrator has connected a Docker engine.

Docker Registry

What: Lists repositories and tags, reads manifests, retags images by digest and deletes images in a container registry.

The Docker Registry node's panel in the editor: the header with the node's icon and name, and its Settings tab.The Docker Registry node's panel in the editor: the header with the node's icon and name, and its Settings tab.

Configuration: operation (required: listTags, getManifest, retag, deleteManifest, listRepositories), registry (required), repository, reference, newTag, bearerToken or username and password, insecure (default off), timeout (default 60 000 ms).

Schema Validator Guard

Now documented with the other guards in AI & LLM → Schema Validator Guard. It validates data against a JSON Schema, expected types or required fields, and routes each item to passed or failed.

The Schema Validator Guard node's panel in the editor: the header with the node's icon and name, and its Settings tab.The Schema Validator Guard node's panel in the editor: the header with the node's icon and name, and its Settings tab.

Output Format Guard and Rate Limiter Guard

Also documented with the guards in AI & LLM → Guard nodes.

Tips & gotchas

  • Log while you build; trim before production. Verbose logs cost storage and hide the real signal.
  • Inspect a value mid-flow with a Code node that returns what you want to see, for example return { seen: input[0], count: input.length };.

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