nstack CLI

The nstack CLI is used to build modules and workflows on the NStack server.


Having installed the CLI, make sure it’s accessible from your path

$ nstack --version
> nstack 0.5.4

You can find the list of commands and options available by running

$ nstack --help


This section explains the commands supported by the CLI toolkit.


$ nstack info

Displays information regarding the entire current state of NStack, including:

  • Modules
  • Sources
  • Sinks
  • Running processes
  • Base images


$ nstack init <stack>
Option Description
stack The default stack to use to build your service, e.g. python or NStack Workflow Language.

Initialises a new nstack module in the current directory using the specified base language stack. This creates a working skeleton project which you can use to write your module.

If you are creating a module in an existing programming language, such as Python, init creates a module with a single numChars function already created. The initial project is comprised of the following files,

  • nstack.yaml, your service’s configuration file (see module_structure),
  • service.py, an application file (or service.js, etc.), where your business-logic lives
  • an empty packages file (e.g. requirements.txt for Python, or package.json for Node, etc.).

init is the command used to create a new workflow. In this case, NStack creates a skeleton workflow.nml file.


$ nstack build

Builds a module on your hosted nstack instance.


build is also used to build workflows. Remember, workflows are modules too!


$ nstack start <workflow>
Option Description
<workflow> The workflow to start, in NStack Workflow Language

Used to start a workflow as a process. Workflows can either be provided as an argument such as:

Or, if you have built a workflow as a module, you can start it with:


$ nstack ps

Shows a list of all processes, which are workflows that are running on your your nstack server.


$ nstack stop <process-id>

Stop a running process.


$ nstack list <primitive>
Option Description
<primitive> The primitive you want to list.

Shows a list of available primitives. Support primitives are modules, workflows, functions, sources, and sinks.


$ nstack delete <module>

Deletes a module (and thus its functions) from NStack.


$ nstack logs <process>
Option Description
<process> The id of the process.

View the logs of a running process.


$ nstack server-logs

View the full logs of the NStack server.


$ nstack gc

Expert: Garbage-collect unused images to free up space on the server.