I just did some further investigation with Roamresearch and found they convert all app links (e.g., omnifocus:// links) : they translate the scheme (e.g., OmniFocus://) to a domain (e.g., http://omnifocus/).
Normally, a way to work-around websites that change links is to escape the URL with ticks (```). In a Discourse forum post for instance, if you paste a markdown link to a local doc it will be translated; to get around that, you can escape the markdown link, so that later you can at least copy the URL from the web page and paste and paste it in Spotlight, a launcher, and soon in Hook itself (so as to access the resource it references). However, I notice on the Roam site this (escaping of URLs) currently leads to text that is not selectable.
I’ve now mentioned the 3 topics to them. and they’ve already responded to one.
It may be best to follow up directly with them . They are very responsive, and very much into links, so I would expect this to get sorted out. When the dust settles, I’ll update this post.
In any event, the tick solution may be helpful to this forum’s readers beyond Roam. And it’s helpful to keep fragment usage in mind for Single-page applications ( Wikipedia link). We could conceivably provide ways in future for Hook to not treat # as fragments, e.g., if the # symbol is embedded in a URL in a manner that suggests it does not actually represent a prefix to a fragment, i.e., that it’s just part of the path of the URL.
Of course, links to web pages obtained via Hook (or other means) can already be used in RoamResearch.
Topic name. To make it easier for future readers to find/use this information, I’ve renamed this forum topic to Invoking a Hook link in the context of roamresearch website. I recommend other questions about Hook (in different contexts) be in a new or other topic.