K
Kelvin

Private beta · Opens Summer 2026

Calendar, tasks, and notes.
One surface, one assistant.

Kelvin brings your calendar, tasks, and notes into one fast app, and adds a chat assistant that actually does the work — creates events, schedules tasks, edits notes. Not another chatbot wrapper.

15 seats in the closed beta. Free for everyone on the list before launch.

One email in Summer 2026, from Tran. Reply to it and I'll read every word.

T

I'm Tran. I'm building Kelvin alone because every productivity app I've tried makes me do their filing instead of mine.

Building in public · Updates weekly

9:14
5G
Thursday, May 21
Good morning, G
Today
4
Pending
7
Notes
12
Events
10:00Standup
13:301:1 with Sam
15:00Product sync
17:00Pickup kids
Tasks
Review Q3 roadmap
Reply to investor email
Book flight for offsite
water plants every tuesday around 6
Detected
TaskEvery Tuesday6:00 PM
→ Water plants
Tap to edit↵ Create
Home
Calendar
Chat
Tasks
Notes

Features

The four things that make Kelvin not just another app.

Press ":" to capture anything

Type "water plants every tuesday around 6." Kelvin parses the dates, times, durations, priorities, and recurrence from plain English. Review the chips, hit enter. One keystroke from idea to logged.

An assistant that does the work

Streaming chat with full tool access. It creates events, schedules tasks, edits notes — not just describes them. Voice input. Per-session memory. Latency surfaced so you know when it’s thinking.

One surface for calendar, tasks, and notes

Three calendar sources (iCloud, Google, Nextcloud) sync into one timeline. Things-style task sections. Eisenhower 2×2 view. Notes with [[wikilinks]] and a daily-notes view that auto-creates today’s page.

Your data, your backend

Private beta runs on a Nextcloud account I provision for you. Open beta adds Google, Apple, CalDAV, and Outlook — bring your own. I’m not in the storage business. You keep the keys.

Desktop app

Press ⌘+: from anywhere on your Mac.

The Kelvin desktop app registers a global hotkey — same idea as Spotlight (⌘+space), but for your calendar, tasks, and notes. Type a sentence, hit enter. The assistant routes it to the right tool. No tab-switching, no leaving the app you're in.

K
You said

Monday I need to submit the proposal, and remind me to follow up if no response by Thursday for the exec meeting on Friday at 5pm in the board conference room.

esc
Kelvin replied · 1.6s
  • Task Submit proposal · due Monday
  • Task Follow up on proposal if no response · due Thursday
  • Event Exec meeting · Fri 5:00 PM · Board conference room
Linked the two tasks to the meeting. Anything else?
⌘:from any app on macOS
↵ send

macOS first. Windows and Linux follow once the beta is stable.

The first week

What changes for you within seven days.

Day 1

Everything in one place

Your calendar, tasks, and favorite notes show up on one dashboard the moment you sign in. Nothing to import. Nothing to organize.

Day 3

Capture without thinking

You stop opening other apps. Press ":", type "lunch with Sam tuesday at 1," and Kelvin parses it into an event on the right calendar.

Day 7

The assistant does the work

"Move my 3pm to Thursday and add a prep task for it." One sentence. The event moves, the task lands. Anything else?

Questions

Things people ask before signing up.

When does Kelvin ship?

Closed beta opens Summer 2026 to the first 15 people on the waitlist. Open beta follows shortly after. I’m building solo, in public, on a schedule I can keep — not one I have to promise.

What will it cost after the beta?

Beta is free. Post-beta is planned at $8/month, single tier. Everyone on the waitlist before launch gets locked in at that price for life.

Where does my data live?

Private beta: on a Nextcloud account I provision for you, so I can iterate fast on real users. Open beta: bring your own — Google, Apple, CalDAV, or Outlook. Your provider, your keys.

Will it sync with Google or Apple Calendar?

Yes — that’s the whole point of open beta. Private beta is Nextcloud-only while I work out the OAuth flows. Switching is one click later.

Is this vaporware?

Fair question. I built and use Kelvin every day for my own calendar, tasks, and notes — the screenshots above are from the real app, not concept art. The work I’m doing now is making it work for users beyond me, which is exactly what this waitlist validates.

Private beta

15 seats. Free during beta. Direct line to Tran.

Closed beta opens Summer 2026. I'll provision a Kelvin account for you and follow up personally. Your feedback shapes what ships.