Setting the file. One moment.
Skill 18 · Webflow Mcp:interactions
Subchapter 18.12
references/trigger-custom.mdMarkdown3 KBView on GitHub
| controlType | standard |
| Standalone | No |
| Target | [REQUIRED] — only wf:body with value: '' |
| Roles | None |
| Playback | Allowed |
| pluginConfig | {eventName: 'my-event'} |
Custom is the one trigger that must use the hidden body target. It listens for a JS event rather than binding to an element.
{
pageId,
name: 'Custom',
triggers: [{
extensionKey: 'wf:custom',
config: {control: 'play', pluginConfig: {eventName: 'my-event'}},
target: {extensionKey: 'wf:body', value: ''},
}],
timelines: [{
actions: [{
...ACTION,
targets: [{extensionKey: 'wf:class', value: [STYLE_BLOCK_ID]}],
}],
}],
}Emit it in Preview with:
Webflow.require('ix3').emit('my-event');[REJECTED] Any target other than wf:body, and omitting the target
entirely. Both produce the same message from different places: a wrong key is
caught by findTriggerTargetContextError, an absent target by the missing-target
branch in findTriggerInvariantError.
Fragment: must use the hidden "wf:body"
[REJECTED] Action targets wf:trigger-only or wf:trigger-only-parent. There is
no trigger element to bind against.
Guard: findActionTargetContextError
eventName written at config level instead of config.pluginConfig is stripped
before persist, so the trigger stores with no event name and can never fire. The
write returns success and a read echoes the payload without it — see the
silent-strip rule in envelope-and-targets.md.
The Interactions panel flags it. Verified on an interaction stored that way:
the Event Name field renders empty with a yellow “No event name” warning
beside it. That makes this the rare [SILENTLY-DROPPED] case with a human-visible
recovery path — nothing in the API surfaces it, but the panel does.
So when a user reports a custom trigger that never fires, send them to the panel before re-reading the payload. An empty field with that warning confirms the event name was addressed at the wrong level.