Marksidian keeps the document rendered while you type; only the line under the cursor shows its Markdown. It opens the .md file where it already is, in the repo your agent is working in or in a folder of notes, and saves back the same plain text. Uninstall it and your files are exactly where you left them.
One-time · 14-day refund · Apple Silicon and Intel · currently 0.3.16
** markers. The table, checklist and code block above it stay rendered.plan.md. There is a status table in it, and one cell is wrong.An AGENTS.md or a spec works the same way. The file stays where it is.
plan.md while this window had unsaved edits. Nothing is overwritten until you pick.Switch modes from the View menu or by clicking the mode name in the status bar; ⇧⌘E goes straight to Reading.
This is the bottom of the same plan.md. The equation and the diagram are rendered in the document, and the cursor is on the plain line under them. Click the diagram and the cursor moves into its mermaid fence.
The raw Markdown as it is on disk, with line numbers and syntax colors. Good for a quick sanity check, or for the days you just want a text editor.
![Source mode showing plan.md as raw Markdown with line numbers down the left: pipe-table rows, a task list with [x] and empty boxes, a fenced bash block, a paragraph with raw ** markers, and the start of a $$ math block. The cursor is on line 12, the ## Cutover checklist heading, and the status bar reads Ln 12, Col 8.](img/plan-source-dark.webp)
The same fonts, widths and section indent as Live Preview, so the page looks the same after you switch. The outline lists every heading; click one to jump there, and the status bar carries a word count and a reading time.
Click a cell and type. Enter or Tab commits it: that one cell is rewritten in the source and the other rows are untouched. Escape throws the edit away. Tab moves to the next cell, adding a row at the end; the buttons underneath are + Row, + Column, − Last Row, − Last Column, plus column alignment.
One shortcut normalizes the document: it makes bullet markers consistent, renumbers ordered lists, aligns table pipes, puts one blank line between blocks (and no more than one), and strips trailing spaces. Fenced code and math are left alone, and ⌘Z puts the file back.
LaTeX between dollar signs renders with KaTeX, inline or as a block, and a mermaid fence turns into a diagram. Click either one and the cursor lands in the source that produced it.
Browse and install themes from Settings (⌘,), each with a preview screenshot; installed ones work offline, and the built-in look follows the macOS appearance setting. About 5% of published themes fetch fonts or images from a remote server, so theme CSS is stripped of every @import and remote url() first.
![alt|300] sets a width.> [!NOTE] blocks render as callouts; footnotes link in both directions..md, so it is in Finder's Open With menu and can be set as the default there.One payment through Stripe; the receipt is the license, and there is no activation server. Every update through 1.x is included, and the app is at 0.3.16 today. For a refund within 14 days, reply to the receipt.
The build is public, on the releases page and in Homebrew, and the app never asks for a key. Use it first. If you keep using it, pay for it; that is what funds the next release.
Typora costs $14.99 for three devices, runs on Windows and Linux as well as macOS, and uses its own theme format. If you want one editor across all three, buy Typora. Marksidian is macOS only, and it is built around the source staying in view: the cursor line shows its Markdown, and a table edit changes one cell in the file.
Vault-style note apps are free, and they are a whole system around a folder: search, backlinks, plugins, a graph. Marksidian reads the same theme format and opens the same files without the rest of it.
The viewers you already have — the VS Code preview, Quick Look — render Markdown well, but you cannot type into what they render.
Yes. The build is public: the DMG is on the GitHub releases page, and brew install --cask dciobanu/tap/marksidian installs the same file. Use it on real work and buy the license when you decide to keep it. If you buy and change your mind within 14 days, reply to your Stripe receipt and you get a refund.
Yes. Marksidian opens ordinary .md files from anywhere on your Mac, including files inside a notes folder or a vault another app manages. It does not import, index or move anything, and it writes back the same plain text.
Yes. Agents write plans, specs and CLAUDE.md as plain Markdown on disk, and Marksidian edits that file in place, so the agent reads your version on its next turn. If the agent writes while you have unsaved edits, the window asks before it reloads.
In two cases. The theme gallery fetches the listing, the preview screenshots and, when you install one, its theme.css and manifest.json from GitHub, and a remote image you put in a document loads over https the way it would in any renderer. Theme CSS is sanitized when it is downloaded and again every time it is read, so an installed theme cannot pull fonts or images from anywhere. There is nothing to sign in to and nothing that reports back.
Stripe sends you to a download page with the Apple Silicon and Intel builds. Your Stripe receipt is your proof of purchase, and there is nothing to enter in the app. Every update through 1.x is included.
A Mac with Apple Silicon or Intel, on macOS 11 or later. The download is about 100 MB. The app is not notarized yet, so Gatekeeper blocks the first launch: open System Settings, go to Privacy & Security and click Open Anyway, or run xattr -cr /Applications/Marksidian.app in Terminal. Notarization is on the list.
I built this because Claude Code kept leaving me plan.md files with a status table in them, and every editor I had either showed me the pipes or hid the source completely. Marksidian is the middle: the table stays a table, the cell I change is the only thing that changes in the file, and the agent picks up my version on its next turn. It is Electron, CodeMirror 6 and markdown-it. There are 900 Playwright tests, and the version history is on the releases page. If something is wrong, reply to your receipt; I read those.
— Dorin Ciobanu