The idea is to create a host HTML document with a text form field that can send arguments to Girder:
....where sendEvent() would be a generic function that receives its value from the text field 'inputText' and sends it to Girder as arguments (payloads) upon the event.
<input type="text" name="inputText">
<input type="button" value="Send Text" onClick="sendEvent(document.forms['userInput'].elements['inputText'].value);">
Anyone have any ideas how to accomplish this?