My favorite quick-note text editor, WriteRoom is out today with an update that adds url-scheme access.
- Create in a folder (uses .txt or custom default): new/folderpath/
- Create with non-default extension (like .md): new/file.md
- Create with body text: new/myfilename?body=Text goes here
- Open from a folder (uses .txt or custom default): open/folderpath/filename
- Open with a non-default extension (like .md): open/filename.md
- Append text: open/myfile.txt?append=Text goes here
- File search: writeroom://search/mysearchterms
There's also support for the FoldingText file extension (.ft) as well.