Delay function

Learn more about the delay workflow function within Knock's notification engine.

A delay function does just what it sounds like: it delays the execution of the workflow for some amount of time, then proceeds to the next step. There are two types of delays we support in Knock today: "wait for set interval" and "wait for a dynamic duration."

Wait for a set interval

The "wait for set interval" delay type waits for an interval of time (provided by you in the workflow editor) and then proceeds to the next step.

Set interval delay functions are helpful for the following use cases:

  • Check to see if a user's seen or read an in-app message before sending an email
  • Remind a user about a pending invite they haven't accepted

Wait for a dynamic duration

You can also set the length of your delay duration dynamically using a variable. You can use any of the data, recipient, actor, or environment variables associated with the workflow run to set your duration.

When specifying a dynamic delay duration you must provide one of the following:

  • An ISO-8601 timestamp (e.g. 2022-05-04T20:34:07Z) which must be a datetime in the future
  • A relative duration unit (e.g { "unit": "seconds", "value": 30 })
  • A window rule (e.g { "frequency": "daily", "hours": 9, "minutes": 30 })

A dynamic duration must be available to be resolved via the key you specify on the given schema, meaning that if you specify a key of delayUntil in your data schema, your workflow trigger data must contain either an ISO-8601 timestamp, a valid duration unit, or a valid window rule.

When the key specified is missing or resolves to an invalid value, a corresponding error will be logged on the workflow run, and the delay will be skipped.

Using workflow cancellation with delays

In cases where you're waiting to see if a user will complete an action before sending a notification, you can use our workflow cancellation API to ensure a user doesn't receive an unnecessary reminder.

If the user completes the action you were going to remind them about, cancel the workflow to keep any additional notifications from being sent.

Frequently asked questions