Stay calm and write. Capydown does the formatting.
Write with Typora-like calm. Publish to WeChat in one click.
A desktop Markdown editor for WeChat Official Account (公众号) writers. Formatted the moment you finish, proofread by AI before you publish.
Free & open source · macOS / Windows / LinuxFormerly LazyBox / Slothdown
Writing
Type Markdown and see it typeset instantly. Markers appear only where your cursor is; the rest of the time there is only your text.
Three editor themes, following the system dark mode if you like
Built on CodeMirror 6: headings, emphasis, images, tables and Mermaid render as you type.
Open, don’t edit, close — the file is unchanged. Line endings, indentation and table alignment are never reformatted.
F8 dims everything but the current paragraph; F9 keeps the current line centred.
⇧⌘L toggles the sidebar; switch between the file tree and an outline you can click to jump.
⌘P finds articles, ⇧⌘P finds commands, ⌘/ flips to source mode.
Pasted or dropped images go to assets/ beside the document with a relative path — or to your image host.
In the editor · v0.3.0
No permanent toolbar. Select text and a floating toolbar appears; rest on an empty line and a “+” shows up; right-click for a native menu. All of them run the same commands as the menus, and all can be undone.
Bold, italic, strikethrough, inline code, link, headings 1–3, quote. Active formats are highlighted; hover for the shortcut.
Insert a heading, list, quote, code block, table, image, divider or Mermaid diagram — arrow keys and Enter work.
Paragraph, format, insert and proofread on right-click; settings, light / dark and the 公众号 preview at the sidebar’s bottom-left.
公众号 formatting
Press ⌥⌘P for the 公众号 preview, pick a theme, click “Copy to 公众号” and paste into the WeChat editor. No more styling paragraph by paragraph.
The panel renders exactly as WeChat will; styles are inlined on copy so nothing shifts on paste.
Three article themes with adjustable font, size, accent colour and code style, plus your own CSS.
WeChat can’t read local files, so Capydown tells you which images to re-upload in the backend.
Export & Open With · v0.3.0
The same draft exports to PDF for your editor or Word for whoever wants to mark it up. Right-click any .md file to open it with Capydown.
Typeset with the editor theme: A4, page numbers, code highlighting, tables, local images and Mermaid; headings never strand at a page bottom.
Heading styles, lists, quotes, code blocks and tables survive; images are embedded and scaled to the page width.
Registered as an “Open With” app for .md without taking over the default. Files outside the workspace open with their folder.
Two AI helpers
Once published, WeChat lets you change at most 20 characters of an article. So AI in Capydown does exactly two things, both before you hit publish.
Only definite errors, never a rewrite of your voice. Every change is your call.
Candidates drafted from the full text, right in the publish dialog.
Bring your own API key. Requests go straight from your computer to the provider you choose. Capydown has no server; your key stays on your machine.
Text is sent only when you start a proofread or ask for titles.
Shortcuts
Menus, shortcuts and the command palette share one command table — what you see is what works.
On Windows / Linux, ⌘ is Ctrl and ⌥ is Alt. Full shortcut list (zh)
FAQ
Capydown is Capybara + Markdown. Capybaras are famous for staying calm about everything — the right mood for focused writing, hence the slogan “Stay calm and write. Capydown does the formatting.” It is the same app as LazyBox / Slothdown (renamed to Slothdown in v0.3.0 and to Capydown in v0.4.0). Existing users just install the new version: the preferences, AI settings and workspace list of the previous version are carried over on first launch, and the old data is left untouched.
No. Capydown is an independent open-source project that takes Typora as its reference for the writing experience. What it adds is 公众号 formatting and pre-publish proofreading; if you don’t write for WeChat, Typora remains a great choice.
Free and open source (MIT), no account. AI uses your own API key and is billed by your provider; writing and formatting work fully without it.
macOS (Apple silicon and Intel) is the primary development and test platform. Windows and Linux builds (Capydown-<version>-…) are produced automatically with each release and are lightly tested — bug reports welcome.
The build isn’t signed yet. Move it to Applications and run xattr -cr /Applications/Capydown.app in Terminal.
WeChat can’t read files on your computer. Capydown warns you before copying; re-upload those images in the backend, or configure an image host (GitHub, Aliyun OSS, Tencent COS, Qiniu, Cloudflare R2 …) so new images upload on paste.
Tables are edited as Markdown source, math and HTML blocks aren’t rendered, rich text from the web pastes as plain text, and the 公众号 preview scroll sync is one-way. All on the roadmap.
