workflow_dispatch fallback to run a scheduled workflow manually in CI

By Kaveh Alemi·Latchkey

A schedule-only workflow has no "Run workflow" button, so you cannot test it or re-run a missed slot on demand. Add workflow_dispatch alongside schedule to get a manual trigger.

What this error means

You want to test a nightly workflow or re-run a missed run, but there is no manual run option because the workflow only has an on: schedule trigger.

on:
  schedule:
    - cron: '0 3 * * *'
# No "Run workflow" button appears in the Actions tab.

Common causes

Only schedule is configured

Without workflow_dispatch, GitHub shows no manual run control for the workflow.

You need to re-run a missed slot

A skipped or delayed cron slot cannot be replayed unless a manual trigger exists.

How to fix it

Add workflow_dispatch with optional inputs

1. Add workflow_dispatch to the on: block.
2. Optionally define inputs to parameterize manual runs.
3. Use the "Run workflow" button or gh workflow run to trigger it.

on:
  schedule:
    - cron: '0 3 * * *'
  workflow_dispatch:
    inputs:
      dry_run:
        type: boolean
        default: false

Trigger manually from the CLI

Once workflow_dispatch is present on the default branch, run it with the gh CLI.

gh workflow run nightly.yml -f dry_run=true

How to prevent it

• Always pair schedule with workflow_dispatch.
• Expose inputs so manual re-runs can vary behavior.
• Document how to replay a missed nightly run.

Frequently asked questions

Related guides

References

• GitHub Actions documentation
• Workflow syntax for GitHub Actions