How to use the Julia plugin

Run Julia scripts for numerical computing and data science inside a container as flow steps.

Common properties

containerImage defaults to julia: latest. Pin a specific version (e.g., julia: 1.10) for reproducibility. taskRunner defaults to Docker and can be overridden for other execution environments.

Tasks

Script runs inline Julia code defined in the script property — best for short, flow-specific logic. Commands runs shell commands (e.g., julia main.jl) against script files; use it when your code lives in namespace files shared across flows, or is cloned from a Git repository with a preceding Clone task.

For package dependencies, install them in beforeCommands with julia -e 'using Pkg; Pkg.add("DataFrames")'. For larger environments, include a Project.toml and Manifest.toml via namespace files and run julia --project -e 'using Pkg; Pkg.instantiate()' in beforeCommands to restore the exact package state.

Triggers

ScriptTrigger polls by running an inline Julia script on a schedule (default every 60s) and emits a flow execution when exitCondition matches (for example exit 42 to watch for a specific exit code). CommandsTrigger works the same way but runs shell commands instead of an inline script.

Both triggers default to edge mode (edge: true), which fires only on a transition from not matching to matching, so a condition that stays true across multiple polls does not fire on every interval. The previous result is stored in the namespace KV store keyed by flow and trigger id.

Use exit(42) in your Julia script to signal a condition you want to watch. The exitCondition also accepts a regex (or plain substring) matched against vars emitted via the : : {"outputs": {...}}: : convention on successful runs.