How do I list extensions installed from VSIX?

I'm using Codium with some extensions I installed from VSIX since they're not available on Open VSX. I want to get a list of them (so that, for example, I can check if they've been added to Open VSX or check for updates), but I can't figure out how to do that easily. The only way I've found is to go through all extensions one-by-one and check if they have a Marketplace link (or other marketplace info like install count).

Research

• Managing Extensions in Visual Studio Code
  • § Install from a VSIX - only says how to install and nothing after that
  • § Extensions view filters - There doesn't seem to be a filter for this
  • § List installed extensions
• VSCodium docs § Extensions + Marketplace - refers to MS docs
• codium --help § Extensions Management
  • codium --list-extensions just shows names, no details. I also tried adding --show-versions and --verbose

In the user extensions.json file, it looks like ones that were installed from VSIX don't have a uuid under identifier and have very little metadata (e.g. no id).

In my case, the file is at ~/.vscode-oss/extensions/extensions.json and this jq command gets the list:

file=~/.vscode-oss/extensions/extensions.json
jq -r '.[] | select(.identifier.uuid == null) | .identifier.id' "$file" | sort

(For the opposite, use != null.)

Then I found out you can use vsce to query the VSCode Marketplace and the equivalent for Open VSX is ovsx, e.g.

vsce show "$name"
ovsx get --metadata "$name"

So to check if any were published on Open VSX after I installed them, I wrote this Bash script that'll go through the VSIX ones and check if they're on the marketplace, plus double-check the non-VSIX ones:

file=~/.vscode-oss/extensions/extensions.json

for operator in '==' '!='; do
    condition=".identifier.uuid $operator null"
    echo "$condition"
    jq -r ".[] | select($condition) | .identifier.id" "$file" |
        sort |
        while read -r name
    do
        if ovsx get --metadata "$name" > /dev/null; then
            echo "Found: $name"
        fi  # Otherwise ovsx prints an error
    done
    echo
done

This identified one extension, so I uninstalled it and reinstalled it from the Marketplace, and after it has a .identifier.uuid, which seems to confirm this method works! I noticed though, it already had a Marketplace link, so I suppose it would have updated automatically, but no updates were published since I installed it.

Lastly, just to be sure, I did check that all the names in extensions.json match codium --list-extensions.