I've made a Node.js Slack app for unfurling links to MantisBT. (It uses the SOAP API.)
It's available on Gitlab: https://gitlab.com/contextualcode/mantisbtslackbot
With a more in-depth blog post with examples and how to install it here: https://www.contextualcode.com/Blog/Usi ... k-Previews
Hope it's useful to some people!
MantisBT Slackbot (for link unfurling)
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