Selected Text sends ⌘C first; Whole Field sends ⌘A ⌘C; Clipboard uses the current pasteboard.

The chosen transform is applied to that text via RoboCore's transform engine — the same engine that powers Textulon and the {rot13}, {json beautify}, … commands in the Keyboard Shortcut action. Only the “Open in Textulon” output requires Textulon to be installed; the other outputs run entirely inside robo.

Paste in place ends with ⌘V so the transformed text replaces what you started with.
Copy to clipboard only stops after putting the result on the clipboard.
Open in Textulon launches the Textulon app with the acquired text and your chosen transform pre-selected, for a glance/tweak before paste-back.

Auto inspects the acquired text, ranks the applicable transforms, and applies the top-ranked one — JSON-looking input gets JSON Beautify, URL-encoded text gets URL Decode, etc. Combine with Paste in place for a one-key “do the right thing.”