Launching today
OpenMarkdown
A markdown editor you and your agent co-edit
183 followers
A markdown editor you and your agent co-edit
183 followers
A fast, light markdown editor that opens any `.md` file instantly. Your agent reads, writes, and co-edits the same file you're in — through a CLI, an agent plugin, and MCP. Local-first: no account, no telemetry, your files never leave your disk.
a co-editing markdown tool is a really clean idea, I've had too many docs where an agent's edit and mine collide and one of us silently overwrites the other. does it show live cursors/diffs while the agent is writing, or do you only see the change after it commits its edit?
OpenMarkdown
@omri_ben_shoham1 Thank you for your interest 😄 (and no — neither of you silently overwrites the other; a collision just makes the agent re-read and retry.)
Two honest UI caveats for now: no live cursor showing where the agent is (no Google-Docs presence marker), and no red/green diff yet — you see the result appear live, in place, not a before/after.
A diff view is the piece a few folks here have asked for, and your question splits it neatly into two modes I'm weighing:
- live diff — the agent writes, then leave a notification on the banner. click to jump to the newly added section (possibly highlighted in a box); and
- review diff — it commits, then you see a before/after to accept or reject (curosr like).
They could co-exist, if they doesn't affect the response speed too much. Which one do you find more useful?
Keeping the Markdown file as the source of truth while allowing section-scoped agent edits is a strong design choice. How are you thinking about provenance—showing which passages came from the user versus the agent after several rounds of co-editing?
OpenMarkdown
@amir_mehrabi Thank you! Keeping authorship distinguishable across several rounds is a great question — and since it's local-first, the .md file is the ground truth, so whatever we do has to live in the file.
Rather than one universal "color the agent's text" layer, I lean toward letting the scenario decide:
- Pure formatting (say, CSV → table): I only care that it's correct — edits happen in place, no provenance needed. (Whether in-place edits should also offer an in-editor review/marker came up in another thread — at least the user should get the choice.)
- Writing a report, where the agent pulls a section in from a repo: a lightweight in-text record fits — e.g. "- [x] @agent · completed 2026-07-18". A timestamp right there in the file is welcome/acceptable.
- A shared task board: you can carve out a dedicated agent-response area in the doc itself, so provenance becomes structural (like the screenshot).
Curious — what scenarios do you reach for most? Would love to figure out together how to make it better~
Opened a few of my old notes and the instant load felt surprisingly snappy. Loved that my agent can drop edits straight into the file without any setup.
OpenMarkdown
@ravzaerbeyler The "no setup" part is the whole idea — writing to the file is the integration, nothing in between. Same reason it loads snappy: just plain files. Thanks for the real spin~
Curious what sets this apart from collaborating with an agent on a .md file in something like VSCode?
OpenMarkdown
@inferhaven Thanks for your question 😊 You can absolutely point an agent at a .md in VS Code.
First, OpenMarkdown is a fast markdown surface, not an IDE.
It renders, opens instantly or a quick peek-and-fix, and stays out of the way.
The co-edit path is built for the shared-file case, section-scoped, with your cursor preserved and per-section conflict checks.
It's not a strict replacement. I still live in VS code for code editing. However I do see trend that coding agent is getting better than ever; I use less VS code recently.
OpenMarkdown is for when you want the quick peek into markdown view/edit.
Easiest way to feel the difference: the interactive agent demo on the landing page, install by pasting a prompt into your agent~
Now this is pretty cool. Do you have plans for version control?
OpenMarkdown
@austinbuhl Thanks 😊 Since every file is just plain .md on your disk, it already works with whatever you use — git, Time Machine, your sync folder. Built-in version history inside the app isn't there yet; git has covered it for me so far. Curious what you'd want most: full in-app history, or something lighter like "undo the agent's last edit"? Would love your take~
@xueyanzhang I think a simple "Undo the agent's last edit," would be awesome.
Glad to know there's Git support.
OpenMarkdown
@austinbuhl Love it — that's the exact one I keep circling back to myself. It's the honest sweet spot: pop the agent's last edit without unwinding the stuff the I just typed, since we're both writing into the same buffer.
Not shipped yet, so I won't oversell it — but you've bumped it up my list, and it's the lighter cut I'm most tempted by.
And yeah — they're just plain .md files, so git and Time Machine treat them like anything else; nothing special from our side. Appreciate you weighing in~
There are countless of markdown editors out there, and I failed to understand what seperates yours. You should pivot towards that; why would someone use this over Obsidian or similar tools for example. Good luck!
OpenMarkdown
@vitohacker Totally fair — it's a crowded space, and honestly I'm a heavy Obsidian user myself (it's my knowledge base; VS Code is my IDE; Notes (MacOS app) was my scratchpad). OpenMarkdown isn't trying to replace any of them — it came from a few specific frictions those tools left me with:
1. Opening a single file. Obsidian is vault-based — to glance at one design.md or double-check a spec, I have to open a vault. VS Code cold-start is slow. OpenMarkdown opens any .md instantly — no vault, no project.
2. Composing prompts. It's my $EDITOR, so I can write long, structured prompts for my agent without a stray newline firing off a half-written message.
3. Fleeting notes in plain text. Quick thoughts used to land in Notes, but that's WYSIWYG — fiddly to format, and not portable. Here they're just .md: openable in any app, yours forever.
4. The actual new thing — co-edit. Over MCP, the agent you already use can edit the same file alongside you, section-scoped, so you don't clobber each other. That's the part no general markdown editor does.
So it's deliberately narrow — a fast, local-first surface for the human + agent shared-file loop, not another PKM trying to out-Obsidian Obsidian. If you want to feel the difference, the Bring-your-agent guide is the fastest way in: https://openmarkdown.dev — appreciate the honest nudge
honestly the local-first setup is exactly what i needed, but one thing i'd love is a diff view right inside the editor so i can actually see what my agent changed when we co-edit. kind of hard to trust the changes otherwise
OpenMarkdown
@rabia584457 Really glad the local-first part clicks! And you've named the real tension in co-edit: trust.
Today it's simple: the file stays a plain .md on disk, and Cmd+Z reverts an agent edit like any other.
An in-editor diff is the thing I keep going back and forth on. I've deliberately kept agent edits as plain edits — fast, no approval step — instead of a review tray you have to clear. But your point is exactly the counterweight: without seeing the change, trust is harder.
Honestly, I don't think one approach just wins outright. We're weighing whether edit-in-place and an in-editor diff can coexist — the best of both, or at least leaving the choice to you. We've already looked into the Agent Client Protocol (ACP) (https://github.com/agentclientprotocol/agent-client-protocol) as one path to that in-editor diff.
So which would you actually want: a persistent diff view, or just a clear "here's what changed, undo if you don't like it"? Would love your honest take~