You SSH in to tweak one line of an nginx config. The remote box has vi and an opinion about it. Or you scp the file down, open it locally, edit, scp it back, and hope nothing changed underneath you in between.
Voltius 0.6.0 removes that whole loop. Open a remote file from the SFTP browser and it opens in a real editor — syntax highlighting, undo/redo, multiple tabs — right inside the app. Save writes it straight back over SFTP. No download, no local copy to clean up, no round trip.
A real editor, not a textarea
The editor is CodeMirror 6, themed from the same palette as the rest of the app, with language modes for the files you actually edit on a server — configs, shell scripts, YAML, JSON, Dockerfiles, and the usual programming languages. You get a VS Code-style tab bar across the top: drag tabs to reorder them, and the active tab takes Ctrl+S to save.
Auto-save is there if you want it — a global toggle plus a per-editor switch — with either an immediate or debounced write, and a configurable max file size so you don't accidentally pull a 2 GB log into a text buffer. There's a guard against opening files that are too large, binary detection so you don't get a screenful of mojibake, and a dirty-close prompt so a stray Ctrl+W can't silently drop your edits.
The interesting part is the diff
The feature this was really built for is comparing files. Drag one editor tab onto another — or onto the editor area — and Voltius opens a diff between them. And because every file in Voltius is just a handle to a host (local included), the two sides can be anything:
- local ↔ remote — what you have locally vs. what's deployed
- host ↔ host — staging's config vs. production's, side by side
- remote ↔ remote — the same file on two boxes that have drifted
The diff isn't read-only. Chunks are color-coded — green for additions, red for deletions, yellow for in-place modifications — with VS Code-style hatched filler so the two sides line up visually even where one is empty. Each chunk gets an apply ribbon: a trapezoid that connects the change across the gutter with a button to push that hunk from one side to the other. Prev/next buttons in the toolbar walk you through the changes, and you can collapse the unchanged regions to focus on what actually differs. The diff itself stays editable, undo/redo and all.
Why it's a MergeView underneath
The honest reason the diff is this capable is that we didn't build a diff engine. CodeMirror 6 ships a MergeView that already does the alignment, the chunk classification, and the revert-across-the-gutter semantics. We mirrored its apply-direction model rather than inventing our own, and spent our effort on the parts that were genuinely ours: the ribbon geometry (the trapezoid paths and where each button anchors), driving next/prev off the viewport midpoint so navigation advances correctly even for chunks scrolled off-screen, and guarding apply against a stale chunk when two applies race.
That last one is the kind of bug you only hit once you make diffs editable: apply hunk A, the document shifts, and hunk B's offsets are now wrong. The fix is to re-resolve the chunk against the current document at apply time instead of trusting the offsets you captured when you rendered the ribbon.
It works everywhere a file does
Because the editor sits on top of the same SFTP layer as everything else, the surprising surfaces come for free. You can edit local files, not just remote ones. The quick-connect panel gets its own lightweight SFTP so you can open and edit a file on a box you haven't even saved as a host. Even Docker container files work — writes stream into the container instead of going through a normal SFTP handle.
The whole thing is open source, like the rest of Voltius — the editor lives in the same repo. If you've ever scp'd a file down just to change one line, this is the feature for you.