classic-workflow

The Classic Workflow Engine

Flow Designer is what ServiceNow recommends and flow-designer is the skill for it. This is the other engine — the one that still fulfils catalog items on most instances that have been live more than a few years. blast-radius says outright that legacy workflows are not scanned, so an agent that cannot read one is blind to a large part of what a record actually does.

Every tool here carries a ⚠️ LEGACY marker in its description. That is guidance about what to build, not permission to ignore what exists.

The version model — read this before changing anything

This is the part that catches people out, and the tools do not hide it from you:

wf_workflow            the workflow's identity. Name, table, description. Almost no content.
   └── wf_workflow_version   THE ACTUAL WORKFLOW. One per checkout. Has `published`.
        ├── wf_activity      steps — belong to a VERSION, not to the workflow
        └── wf_transition    edges between activities — also per version
wf_context             one running instance of a published version against one record

A workflow is not edited in place. Checking it out creates a new wf_workflow_version with published = false; you edit that; publishing flips it to published = true and retires the previous one. Records already running keep executing the version they started on — which is why a fix does not apply to work in flight, and why wf_context rows can point at versions nobody can find in the UI.

So the first question about any classic workflow is which version:

await snow_query_table({
  table: "wf_workflow_version",
  query: "workflow.name=Standard Change Approval^published=true",
  fields: "sys_id,name,published,sys_updated_on",
})

The trap in the write tools

snow_create_workflow_activity and snow_start_workflow both set the workflow_version field, and both resolve a name by looking it up in wf_workflow — which returns a workflow sys_id, not a version sys_id. wf_activity.workflow_version and wf_context.workflow_version reference wf_workflow_version. Passing a name therefore points the new row at a version that does not exist.