Open one app.
It already knows.

Jackdaw is the app you open to your own brain. Mail, notes, journals, pages, tables and files, all in one window. Ask it anything and the answer comes back out of your own material.

Try the demo Meet the brain

Jackdaw is the app. Mantle is the brain it opens. The demo is the real app, on a read-only brain we filled in for you. Nothing to install.

A screen-printed writing desk by a window: an open notebook, a stack of sealed envelopes, a mug and a fountain pen, with a jackdaw perched on the corner and a round clock on the wall.

Everything you keep,
in one window.

Chat with it. Read your mail. Write a note, keep a journal, draft a page, build a table, park a file. Same window, same search, same memory behind all of it.

You stop hunting for the thing you know you saved.

Chat
Mail
Notes
Journal
Pages
Tables
Files
Tasks
Calendar
Contacts
Drawings
Apps

The parts, up close.

Every pane is a real tool, not a text box with a name on it. Four worth a slow look, then the rest.

Pages: Rich documents: callouts, columns, tables, to-dos, code, maths and Mermaid diagrams. You type into a private draft. Commit publishes it, and the brain reads it once rather than on every keystroke.
Tables: Each table is a real SQLite workbook with tabs and typed columns, formulas and cross-tab references. Ask a question and the assistant runs read-only SQL on it, so a big table stays useful.
Formulas: A stored model of a calculation, with branches, lookup tables and units. It evaluates with a derivation trace and fails loud rather than returning a silent zero.
Apps: Describe what you want. A specialist writes real React, compiles it, fixes its own build errors and leaves a live preview in your palette. Each app has its own database and runs sandboxed.

and 21 more

Notes: Quick markdown capture, summarised and mined for facts on save.
Journal: First-person entries with a mood and a life area. They feed the block about you that every agent reads.
Tasks: Status, priority and due date. The assistant can manage them too.
Calendar: Start, end, place, recurrence, and reminders that reach you on the channel you last used.
Contacts: The gate for mail, both ways: who gets read in, and who the assistant may write to.
Secrets: A sealed vault. Titles and tags are searchable; the values are never shown to any model.
Watch it think: A trail of what it searched and read, then the reply streaming in. Stop it mid-sentence if it is wrong.
Formatted replies: Answers come back as documents: headings, tables, checklists, diagrams. Save any reply as a page.
Dictation and attachments: Speak into the composer, or attach images, PDFs and spreadsheets to a question.
Block editing: Every block has a stable id, so the assistant rewrites one paragraph, not the document.
Diff review: A review mode paints exactly what a commit will publish, block by block, with discard and restore.
Sub-pages: Split a long page along its headings, or lift one section into a child.
Mentions: An @-mention of a person or a document becomes a real link in the brain, with backlinks.
Markdown in and out: Toggle a page to raw markdown and back. Paste a Notion export and it becomes real blocks.
Export: Pages and notes to Word, tables to Excel with a totals row, or the raw workbook as SQLite.
Search: Command-K across the whole brain, with navigation built in.
Permalinks: One link resolves any item to the screen that edits or shows it.
Live screens: A screen repaints the moment new mail or files land. No refresh.
Desktop app: Linux, macOS and Windows, with notifications and deep links. Keep several brains, each with its own login, and switch with a shortcut.
Themes: Forty-one palettes, light and dark, every pair contrast-checked before it ships.
The guide inside: The documentation is readable in the app and indexed into the brain, so the assistant explains itself with citations.

Ask the way you would ask a person.

Everything that arrives gets read. Mail, notes, files, the lot. Not sorted into folders, read. So a plain question months later gets a plain answer, and it shows you what it read to get there.

It connects things too. Ask who somebody is and it can tell you where they turn up, what is true about them now, and what used to be.

And you watch it work. A trail of what it searched and read, then the answer, streaming. Stop it the moment it is wrong.

Example

“What did we settle on for the gantry rebuild?”

Linear rails, decided on 20 March after the belt test failed. You capped the parts budget at four hundred.

Read

NoteLister gantry
MailRay, 20 Mar
Filerail-spec.pdf

A screen-printed twig nest holding a collection drawn in gold: a key, a ring, a coin, a bead, a button and a bottle cap, with a jackdaw leaning over to look at them.

It keeps working when you close the tab.

Jackdaw is the window. The brain behind it does not stop when you shut it.

A screen-printed jackdaw in full flight against bands of sunset colour, carrying a wax-sealed envelope in its beak over dark hills and two small rooftops.

Mail: A message from someone in your contacts is read, summarised and filed before you have seen it. Mail from anyone else is left where it landed.
Reminders: An event you put in the calendar reaches you as a Telegram message on your phone, at the time you asked for, with nothing open.
Errands: Ask for a piece of research before bed. It arrives as an email in the morning, sent from your own address, with its sources.

You do not have to remember to ask.

Yours, in the boring literal sense.

The brain runs on your own machine. Jackdaw keeps nothing: no database, no session secret, no server code of its own. It talks to your brain and to nothing else.

Every key and password stays sealed on your box. There is no account with us, no tracking, and no third-party script on the page you are reading either.

What leaves is what goes to the providers you chose: chat, voice transcription, vision and embeddings. You pick each of those, and chat and embeddings can run on a model on your own machine.

A screen-printed stone and timber cottage with two lit windows and a stone chimney, a gold-leaved tree beside it and a jackdaw sitting on the picket fence.

There is a brain behind this.

Mantle is the system underneath: one Postgres, six layers of memory, an entity graph, and agents that do the work. It has a site of its own, and that one goes into detail.

Meet the brain

Get it.

Jackdaw needs a brain to open. Run one, then open it in the browser, the desktop app or on your phone.

Run the brain: One command on a Linux box with Docker. It brings up Mantle and the Jackdaw web app together. Install Mantle
Desktop app: Linux, macOS and Windows, pointed at a brain you already run. The macOS build is unsigned today. Download from GitHub
iPhone: On the App Store, free. Want new builds first? The open beta runs on TestFlight. Get it on the App Store, or join the beta
Android: A closed test on Google Play, two steps with one Google account. Staying in for two weeks is what lets us open the store to everyone. Join the testers group, then become a tester
Demo: The real app on a read-only brain we filled in for you. Nothing to install. On a phone, give the app this address and sign in with anything. Try the demo

Open one app.It already knows.

Everything you keep,in one window.