Kurir 2.0 for iPhone and Mac

Mail that knocks first.

New senders wait in the Screener until you say where they go. People you want reach your Imbox. Newsletters go to The Feed. Receipts go to Paper Trail. There is no server to run.

How it works

Linux, Windows and Android are coming soon, on the same core.

In motion

Kurir in half a minute.

The Screener, the Imbox, a reply and the calendar on iPhone, recorded with demo mail. A ring shows where each tap lands, and a voice says what is happening.

The Screener

A stranger's first mail waits at the door.

The first time someone writes to you, the mail stops in the Screener. You see the name, the address and the subject. One tap sends the sender to the Imbox, The Feed or Paper Trail. Another blocks them.

You decide once per sender, or once for a whole domain. Kurir remembers, and everything they send after that goes straight to the place you picked.

The Screener on Mac. Three new senders, each with buttons for Imbox, The Feed and Paper Trail. — The Screener on Mac. Three new senders, three choices each.

Three places, not one pile

Each kind of mail gets its own place.

Every sender you screen in goes to one of three lists. You pick the list once, and their mail keeps going there.

Imbox

Only people you approved. New mail sits on top, under New For You. What you have read moves down to Previously Seen.
The Feed

Newsletters and updates you chose to keep. Read them when you have time. They never crowd the Imbox.
Paper Trail

Receipts, bookings and shipping notices. Out of the way, and found with search the day you need one.

No server

Your mailbox is the sync.

Kurir 2.0 talks straight to your mail account: iCloud, Fastmail, Gmail or any IMAP server. Your screening choices, rules, snoozes and settings are kept in a hidden folder in that same mailbox. Your iPhone and your Mac both read it, so they agree without a Kurir server in between.

Turn on encryption and that folder is sealed with a passphrase only you know. Other devices get the key when you pair them.

The Imbox on iPhone, with New for you on top and Previously seen below. — The Imbox on iPhone.

Under the hood

One core, an app for each platform.

All of Kurir's mail work happens in one core, written in Rust, a fast language that is not tied to one operating system. It syncs your mail over IMAP, runs the Screener, the three places and your rules, handles snooze, send later and search, keeps your calendar and contacts, and reads and writes the hidden folder with your settings, sealed when encryption is on.

The iPhone and Mac apps sit on top of that core. They are written in Swift, Apple's own language, so they look and feel like the rest of your iPhone and Mac. Kurir Push runs the same core on Linux, in Docker, with no Apple code in it at all.

That is why Linux, Windows and Android are coming. A new platform needs a new app on top of the core, not a new mail client, and the core that does the mail work already runs on Linux today.

iPhoneSwift app
MacSwift app
Kurir PushLinux, in Docker
LinuxApp coming
WindowsApp coming
AndroidApp coming

Kurir core, in Rust Mail sync, the Screener, rules, snooze, send later, search, calendar, contacts, and the settings folder, encrypted when you turn it on.

Every app sits on the same core. The Linux, Windows and Android apps are not built yet.

Getting started

Sign in. Screen. Read.

Sign in with an app password

Make an app password at your mail provider and enter it in Kurir. iCloud, Fastmail and Gmail are filled in for you. Any other provider works with its IMAP and SMTP addresses.
Screen as mail arrives

The first days are mostly screening. After that, new mail lands where it belongs, and the Screener only shows senders you have not met before.
03
Add Kurir Push if you want it

Kurir Push is a small client that keeps checking your mail and pushes new mail to your iPhone. It also sends scheduled mail and saves a backup of your settings once a day, sealed when encryption is on. It runs on a Mac with Kurir open, or on any Linux machine with Docker, installed with one line:
```
$ docker run --rm ghcr.io/cfarvidson/kurir-push \
    install | sudo bash
```
The installer asks for a setup code. Copy it from Settings > Devices > Add Kurir Push in the app, and it knows your account. Read the setup guide.

It also connects Claude Code and other assistants to your mail, calendar and contacts over MCP. More on that below.

Calendar

Your week, with the free time counted.

Connect iCloud, Fastmail or any CalDAV calendar, or subscribe to an .ics link. Day, week and month views show how many hours are still open, and the next meeting sits on top with a Join button.

Kurir's week view on Mac, with open hours per day and the next meeting at the top. — The week view on Mac.

AI and MCP

Bring the model you already pay for.

Kurir's AI features run on the Claude Code subscription you connect in Settings. There is no API key to buy and no Kurir server in between: the mail a feature needs goes straight to Anthropic.

Generate draft on Mac: an instruction, a tone picker and a written reply to insert.

Generate a draft

Write what the mail should say and pick a tone: Auto, Formal, Friendly or Direct. Kurir writes a version from the mail you answer and recent mail with that sender, and Try again adds another to choose between. Nothing goes out until you insert one and press Send.

AI Rules

Some senders mix mail you want with mail you don't. Describe the good ones in a sentence, and a model reads each new mail from those senders and files it where the rule says.

Your mail, calendar and contacts, open to Claude Code

Kurir Push serves MCP. Claude Code and other MCP clients can list, search and read your mail, archive and snooze threads, screen senders and save drafts. They can read your calendar and book, move and cancel events, and keep your contacts and contact groups up to date. Sending a mail, rejecting a sender, deleting an event, and making, changing or deleting a contact or a group always ask you to confirm in the assistant first.

Make a token under Settings > Devices, run the command Kurir shows, and revoke the token there when you are done. Tokens need encryption turned on.

$ claude mcp add --transport http kurir \
    http://kurir-push:8790/mcp \
    --header "Authorization: Bearer kurir_mcp_..."

And the rest

Small tools for the mail you keep.

Reply Later: Set aside the mail you owe an answer, then work through the stack in one sitting.
Snooze: Hide a thread until the day you want it back.
Follow up: If nobody has replied by the date you pick, the thread comes back.
Send later: Write it now and send it Monday morning.
Pin: Keep the few threads you need close at hand.
Search: Search senders, addresses and subjects across all your mail, on the device.
Files: Every attachment in one list, newest first.
Contacts: People and groups, so you can write to a whole group at once.
Collections: Gather threads under a name of your own, out of the Imbox, The Feed and Paper Trail.
Several accounts: Add more than one mail account and switch between them.
Tracking images: Images that report when you open a mail stay blocked, and the thread says how many.
Commands: On the Mac, ⌘K finds any action, folder or setting, and single keys move through the list.

Download

Kurir for iPhone and Mac.

Works with iCloud, Fastmail, Gmail and other IMAP accounts. No Kurir account and no server.