ASMO is a quiet month calendar. Each day holds a list of things to do, with times, subtasks and repeating routines, and a free page of notes underneath. You can use it by hand like any calendar.
What makes it different is the asmo command. Any agent that can run a shell command (Claude Code, Codex) can read your days and change them: add and move items, check things off, and write a day's page in Markdown with pictures, tables and diagrams. Apps without a shell, such as the Claude desktop app, get the same thing through an MCP server. The app itself runs no language model: the agent you already use does the thinking, and ASMO stores exactly what it is told.
Features
- Month calendar: every day shows its items in time order; finished ones are struck through. Click a day for a quick look, double-click to open it.
- A page per day: a rich-text editor for the day's items and notes, with bold, italic, highlight, headings, lists, checkboxes, links and pictures.
- Subtasks and routines: items nest up to three levels. Routines repeat every day, on weekdays, or on the days you choose, and can be skipped for one day.
- Important dates: birthdays, anniversaries and holidays come back every year, in the Gregorian or the Chinese lunar calendar.
- Apple Calendar and Reminders: optionally show your Apple Calendar events next to your items (read through the system, with your permission).
- The
asmo command: everything above from the command line, with JSON answers. Open windows update while the agent works.
- Markdown pages: agents write notes as Markdown: headings, emphasis, links, lists, checkboxes, quotes, tables, code blocks, pictures by file path or URL, and mermaid diagrams drawn by a copy of mermaid that ships in the app.
- Undo:
asmo undo takes back the last change an agent made, and the one before it, until the app is restarted.
- Updates itself: a new version is one click: ASMO checks GitHub Releases and swaps itself in place.
- English and Chinese: the interface follows your Mac, or pick a language in Settings. What you write is never translated.
- Private: your data is a local file on your Mac. Nothing is uploaded and there is nothing to sign in to.
Install
You need a Mac with Apple silicon and macOS 15 or later.
- Download
ASMO-v….zip from Releases, unzip it and move ASMO to Applications. It is signed with a Developer ID and notarized by Apple.
- Open it. That's all.
When it opens, ASMO connects the assistants on your Mac by itself: it puts the asmo command in ~/.local/bin, gives Claude Code and Codex the skill (when they are installed), and registers its MCP server with the Claude desktop app (when it is installed; restart that app once to load it). Settings ▸ AI assistants shows what is connected.
Updates
ASMO checks GitHub Releases shortly after it opens and once a day. When a newer version is out, it asks. Update Now downloads it, checks that it is signed by the same developer, replaces the app and reopens it; Later asks again next time. Settings ▸ Updates has Check for Updates. Your data stays in ~/Library/Application Support/ASMO and is not touched by an update.
Build from source
With Xcode 26:
git clone https://github.com/realAllenSong/ASMO.git
cd ASMO
script/install.sh # builds, replaces /Applications/ASMO.app, installs asmo, the skill and the MCP entry
script/release.sh builds the signed, notarized zip (it needs a Developer ID certificate and a notarytool profile). An iPhone app builds from the same source (script/install-iphone.sh, with your own Apple developer team), but the agent features are Mac-only for now, and the two do not sync yet.
Use it from an agent
After installing, open a new Claude Code or Codex session anywhere and say what you want:
I'm running from 9 to 10 tonight, and tomorrow at 3 I have a call with Li about the lease. Put the lease questions on tomorrow's page as a checklist.
The agent finds the asmo skill, reads the days involved, and writes the changes. You can also run the command yourself:
asmo today # tasks with subtasks, routines, dates and the page
asmo add "Call Li about the lease" --day tomorrow --time 15:00 --end 15:30
asmo set 3f9a --time 16:00 # ids can be shortened to 4+ characters
asmo done 3f9a
asmo list today +7 --open # what is still open this week
asmo undo
Several items at once, with subtasks, as JSON on stdin:
asmo add --json --day today <<'EOF'
[{"title": "Ship the release", "time": "10:00", "end": "12:00",
"subtasks": [{"title": "Run the tests"}, {"title": "Write the notes"}]},
{"title": "Gym", "time": "18:30"}]
EOF
A day's page, in Markdown:
asmo page write today <<'MD'
## Release plan
Shipping **v1.0** today.
```mermaid
graph LR
Tests --> Changelog --> Tag --> Ship
```
| Step | Owner |
| --- | --- |
| Tests | Mei |
MD
asmo page today # the page as blocks b1, b2, … each with its Markdown
asmo page set today b2 <<< "Shipping **v1.0** on Monday."
asmo attach ~/Desktop/photo.jpg --day today --caption "whiteboard"
asmo help lists everything, including routines and important dates.
MCP
asmo mcp is an MCP server on stdin and stdout with the same abilities as tools (day, add_tasks, update_task, write_page, undo and others). The install script registers it with the Claude desktop app; for any other MCP client, add:
{ "mcpServers": { "asmo": { "command": "/Users/you/.local/bin/asmo", "args": ["mcp"] } } }
How it works
- The app listens on a Unix socket in
~/Library/Application Support/ASMO. asmo sends one JSON request and prints the JSON answer; if the app isn't running, it is started in the background first.
- The app is the only writer of its data, so nothing is changed behind its back and open windows stay current.
- Pages are stored as the same rich text the editor produces, so what an agent writes stays editable by hand. A diagram's source is kept inside its picture, so the page reads back as Markdown.
- If you build the app under your own bundle identifier, tell the command with
ASMO_BUNDLE_ID=com.you.asmo.
Privacy
ASMO makes two kinds of network requests of its own: the update check to GitHub Releases, and a preview when you paste a link. Pictures referenced by URL in a page are downloaded by the asmo command on your Mac. Whatever your agent sends to its own provider is between you and that agent; ASMO only receives the commands.
Development
swift test # the date, parsing and planning rules
script/demo-gif.sh # records assets/demo.gif from the demo store
script/build_and_run.sh # Debug build
script/run_test_store.sh # Debug build on a separate test store
asmo ping --test # talk to the test store instead of your real data
The app is Swift, SwiftUI and SwiftData, with an AppKit text view for the day page. The command in CLI/ has no dependencies. See CONTRIBUTING.md.
License
MIT.
Acknowledgments
Diagrams are drawn with mermaid (MIT), which ships inside the app.
