Why can't I access the Shopify API during preview mode?

A task is always run in response to an event. However, for several purposes, Mechanic may also run your task with a preview event, without performing any of the actions the task generates.
We refer to this as preview mode, and it's used for...
  • Showing merchants what actions they can expect the task to perform
  • Determining what permissions the task requires in order to run
  • Performance-related analysis
Because all of these purposes require very fast performance of the task, Mechanic disallows all API requests during preview mode. You can use the {{ event.preview }} variable to make decisions about what should happen during preview mode, like creating stub data that results in the appropriate actions being rendered during preview – a good practice when accounting for preview actions.