MindooDB Blog

Product updates and engineering notes

Selected articles about MindooDB, Haven, the App SDK, and the open-source sample apps built on top.

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  • Haven Desktop for macOS and Windows is ready to download

    Karsten Lehmann · October 29, 2026

    Haven, our end-to-end encrypted, local-first workspace, is now available as a native desktop app: notarized for macOS, signed for Windows on x64 and ARM64. It is built on Tauri 2, stores your data in a local SQLite database, connects local AI agents through MCP without an open network port, and keeps itself up to date. The apps for iOS and Android are in testing, and you can join.

  • What we learned making 12 apps usable by AI agents with WebMCP

    Karsten Lehmann · October 27, 2026

    We gave twelve apps of our end-to-end encrypted, local-first workspace Haven their own tools for AI agents through WebMCP, and connected them to MCP clients such as goose and Claude Code. This post covers how WebMCP differs from MCP, how we reveal tools step by step instead of showing hundreds at once, the design rules that made tools usable for models, what went wrong on the way, why undo and an append-only history are the precondition for letting an agent near real data, and how to keep that data in Europe or on your own machine.

  • The story behind MindooDB Haven

    Karsten Lehmann · October 18, 2026

    From a student knowledge base on IBM Notes/Domino in 2001, through MindPlan, nine years in the IBM Design Partner Program, Domino JNA and the Domino JNX API underneath the HCL Domino REST API, to a fresh start: MindooDB, an open source database in which not even the server can read your data, and Haven, the collaboration client that brings apps together on one surface - and why we drink our own champagne.

  • What do a tree inspector, a flood relief team and a scavenger hunt have in common? Meet Mindoo Cairn

    Karsten Lehmann · October 14, 2026

    Mindoo Cairn is the newest app in the Haven App Store: a shared field map on which a team pins, photographs, sketches and measures together - with pen, finger or mouse, on phone, tablet and desktop, offline, end-to-end encrypted, and merged without conflicts by Automerge when devices meet again, through a server or directly peer to peer. Workbooks turn the same map into a tree inventory after the FLL guideline, a crisis situation map with an incident log, a playground or hydrant inspection with checklists and QR labels, or a city rally with encrypted stations, a comic intro and mini games. Time travel compares a workbook at two points in time, side by side or with a slider. And because Haven is learning to speak WebMCP, an AI model can already search Cairn's workbooks, place markers and draw what it found on the map - work in progress, but worth a look. There is a new site for it at mindoo-cairn.com.

  • Works for my wife - what changed in Haven and MindooDB in September

    Karsten Lehmann · September 29, 2026

    Not every week gets its own article, but the small things add up. MindooDB now speaks four more Automerge data types - counters that sum concurrent increments, real timestamps, atomic strings that are replaced rather than merged, and text cursors that keep pointing at the same words while other people type - and it can answer nested queries that join invoices to their lines, customers and products across databases and even tenants, straight from the document summary buffer. Incoming sync now warms the summary buffer, the virtual views and the full-text index while the data arrives, so a database is ready the moment the progress bar finishes. Haven dropped its sidebar after failing the most honest usability test we have - my wife, a teacher - so views, apps, notes, web pages, diagrams and videos now all live as tiles on the workspace, which in turn gained undo and redo for layout changes, one-click tile arrangements, a maximise shortcut, draggable dividers and an end to overscroll. The App SDK can ask about focus, send notifications and drag data from one app tile into another, with Haven brokering the gesture. The App Builder learned to share builds between developers, send an app to a colleague and copy an existing one; App Store apps now run as hosted bundles with a network allowlist; Teacher's Desk puts lessons into the calendar; and TeamSketchbook gets thirty covers and text boxes.

  • The Haven App Builder - describe the app your team is missing, and an AI writes it

    Karsten Lehmann · September 23, 2026

    Haven has been extensible through apps for a while: the MindooDB App SDK, a set of context files a coding agent can read, and a reference app to fork. That works - and it still asks you to care about where the code lives, who hosts it, and how the result reaches Haven. The new App Builder, itself an app in Haven's App Store, removes all of it. Connect GitHub, Cloudflare and Cursor once, then type a name and a few sentences about the app you are missing and press one button: the builder creates a private repository from a starter template, writes your brief into it, reserves a web address on Cloudflare, wires push-to-deploy, waits for the app to answer, hands it to Haven for installation, and sets a Cursor cloud agent to work - which you can then watch draw an icon, write the app and click through it in a browser. What comes out is an ordinary MindooDB App with its own repository and its own address, and it is safe to run because none of Haven's app isolation changed: sandboxed iframe, logical database ids, permissions you granted at install time, and a network allowlist that blocks anything the app was not allowed to call.

  • Peer-to-peer sync between Haven clients - and reaching the MindooDB server in the cupboard

    Karsten Lehmann · September 22, 2026

    Haven clients can now sync directly with each other over the Iroh network, with no server in the middle: two devices of the same tenant converge device to device, carry on collaborating while the server is down, and hand over the complete signed history afterwards. It arrived as the side effect of solving a duller problem. The crazy-hardware series proved that a MindooDB server fits inside a phone, an Orange Pi and a Wi-Fi router - and then left every one of them sitting at a LAN address. At Local First Conf in Berlin I watched Brendan O'Brien present Iroh: endpoints identified by public key rather than DNS name, QUIC, relays when NAT gets in the way, and a Rust library that compiles to WebAssembly. Both the MindooDB server and the Haven client now speak it, so pasting a ticket into Haven makes the box in the cupboard reachable with no DynDNS, no port forward and no certificate. And once that runtime was in the browser, peer-to-peer sync was a change of argument rather than a change of code path.

  • MindooDB on crazy hardware, part three - a server inside the Wi-Fi router

    Karsten Lehmann · September 12, 2026

    First an emulated x86_64 VM on an iPhone, then an Orange Pi Zero 3W with eight cores and 6 GB of RAM. This time the host is the box that was already in the room doing another job: a GL.iNet Flint 2 AX6000 Wi-Fi router - four ARM64 cores, 1 GB of RAM, 8 GB of eMMC and OpenWrt. It was the bumpiest setup of the three, and both potholes were OpenWrt's: Docker's bridge DNS could not resolve the npm registry during the build, and nftables would not hairpin the published port afterwards. Both are now handled by serversetup.sh itself. After that the server minted its identity in 1661 milliseconds, and Haven pushed a Teacher's Desk tenant to the thing that hands out our Wi-Fi.

  • MindooDB on crazy hardware, part two - a whole server on 14 grams of Orange Pi

    Karsten Lehmann · September 10, 2026

    Last month I ran a MindooDB server inside an emulated x86_64 VM on an iPhone: 75 minutes for the Docker build, 102 seconds for one identity. The hardware actually meant for the job has now arrived - an Orange Pi Zero 3W, 65 x 32 mm, 14 grams, eight ARM64 cores and 6 GB of RAM, $85 from Amazon and ten days lost somewhere between Dallas and Cologne. Same repository, same serversetup.sh, no changes for ARM64: the Docker build took 137.6 seconds and the server identity 649 milliseconds. Then Haven pushed a Teacher's Desk tenant to it over Wi-Fi and synced several thousand encrypted entries to a board that fits in a shirt pocket.

  • Mindoo Vega grows up - Gantt charts, a real spreadsheet, and the project as it was last month

    Karsten Lehmann · September 8, 2026

    Vega used to be a mind map with a Kanban board attached. It now carries a Gantt chart you can drag dates around in, a full Excel-compatible spreadsheet - the TeamGrid engine, 280 formulas, column, bar, line and pie charts - that mirrors your project nodes into cells and writes your edits back to them, and an XLSX export anyone can open. MindooDB's time travel turns into project reporting: open the plan as it stood at the kickoff, or put two dates side by side in a comparison spreadsheet where XLOOKUP has already paired the old and the new rows and the delta columns are written for you. Plus poster printing across any number of sheets with glue strips, links between nodes across maps and tenants, a dockable properties sidebar with Markdown and Mermaid, a node icon library, and better layouting. There is a new site for all of it at mindoo-vega.com.

  • No password, and your workspace on every device - passkeys and workspace roaming in Haven

    Karsten Lehmann · August 25, 2026

    Haven now unlocks with a passkey: Face ID, Touch ID, or whatever else your device uses to recognise you. After your next password sign-in, Haven offers to set one up, and once it works you can remove the password entirely and never type one again. New user ids are created with the passkey option preselected. Administrator ids are the deliberate exception, because an admin account that only opens with this laptop's fingerprint is an admin account you lose with the laptop. And in Haven Enterprise, your workspace itself can now travel: tabs, tiles and your installed apps sync between your devices, encrypted with your user key, with as many separately named layouts as you like - one for phones, one for wide screens.

  • MindooDB on crazy hardware: inside Docker in an x86_64 VM on an iPhone 17

    Karsten Lehmann · August 22, 2026

    We started wondering what the smallest machine is that can run a MindooDB server. The server only relays encrypted data - it never decrypts anything - so the requirements are mostly a Node.js runtime and some disk. While waiting for a box of mini PCs to arrive, I tried the least sensible option I had to hand: a Debian VM under emulated x86_64, inside UTM SE, on an iPhone 17. The Docker build took an hour and a quarter, generating the server identity took 102 seconds. And then it ran.

  • Encrypt this for Alice - user keys and per-document sharing in MindooDB and Haven

    Karsten Lehmann · August 21, 2026

    MindooDB and Haven now give every person a user key that travels with them across every device they approve. Encrypting for a small circle was always possible - mint a key and pass it around by hand, which you can never take back, or have an administrator set up a distribution policy - but now it is simply a recipient list on the document. Take someone off that list and the document key rotates: they lose access on the next sync, attachments included. Key distribution addresses people instead of devices, so a new laptop no longer means rewriting who may read what.

  • A faster sync, live updates, and a workspace you can recover from a sheet of paper

    Karsten Lehmann · July 11, 2026

    The quieter half of this summer's work is under the hood. Haven's sync got a new version that moves less data and puts less load on the server, our servers can now nudge your devices the instant new data arrives so collaboration feels immediate, and the Sync page can push your changes out the moment you make them. And there is a lovely bit of paranoia-as-a-feature: a printable recovery sheet, a page of redundant QR codes protected by a security question, that can rebuild your whole workspace even if every device is gone - scan the codes, sync, and you're back.

  • Mindoo Teacher's Desk - a teacher's whole working day, on data that stays private

    Karsten Lehmann · July 11, 2026

    Mindoo Teacher's Desk is our new commercial app for teachers, and the biggest thing we have built on Haven so far. It brings a teacher's whole day into one place - timetable, calendar, lesson planning and delivery, classes and learners, grades, seating plans, materials, parent conversations, tasks and notes - and because it runs on MindooDB, the sensitive data it holds (children's names, grades, observations) is encrypted so the server operator can never read it, syncs across all your devices, and keeps working offline. It ships in eight languages, installs from the Haven App Store in one click with a demo data set to explore, and its Word-document editing now works on phones and tablets thanks to a document editor we forked and are extending ourselves. Access comes with MindooDB Cloud at €7.99 per user per month or €79.99 per year, incl. VAT - a subscription that covers every Haven app, not just this one.

  • Mindoo TeamSketchbook - collaborative drawing for tablets and pens

    Karsten Lehmann · July 11, 2026

    Mindoo TeamSketchbook is a collaborative sketchbook and infinite canvas for MindooDB Haven: draw by hand on tablets with a pen like the Apple Pencil or Samsung S-Pen - or with a mouse or your finger. Annotate PDFs, present with a laser pointer, compare page revisions, and work offline. Because it is built on MindooDB, two people can draw in the same book on different devices and their strokes merge on the next sync, with a full revision history so you can flip back to any earlier version of a drawing.

  • The Haven App Store - one click from empty workspace to working app

    Karsten Lehmann · July 11, 2026

    Haven now has a built-in App Store. Every app is presented like an app on your phone - a proper icon, screenshots, and a description - and installing one is a single click: pick the app, choose which tenant should hold its data, and it opens ready to use. It is the same catalogue behind our sample apps like Mindoo Vega, TeamEdit, TeamGrid, TeamSketchbook and Teacher's Desk, and organisations can even host their own catalogue of internal apps. Haven itself now speaks eight languages, so more teams get all of this in their own.

  • Search everything in Haven - including the text on the paper on your desk

    Karsten Lehmann · July 11, 2026

    Haven now has real full-text search: type a word and find it inside long notes, e-mails, Word documents and even the files attached to them. It is built and kept up to date right on your device, so it works offline and the server never sees what you searched for. Better still, Haven can read the text inside scanned images and photos of paper documents with built-in OCR, store that recognised text once, and sync it everywhere - so a snapshot of a handwritten-looking invoice becomes findable on every device. And a new Quick-Scan button in the sidebar turns your camera into a document scanner in one tap.

  • Instant answers across thousands of documents - without opening a single one

    Karsten Lehmann · July 11, 2026

    Searching, filtering, sorting and grouping your data used to mean unlocking and reading every document first - slow, and a real problem when everything is encrypted. Haven now keeps a small, always-up-to-date summary of the searchable bits of every document, so questions like 'all open tasks owned by Alice, newest first' are answered instantly, in memory, without ever unlocking the full documents. The same summary powers live lists that update themselves as data arrives, groupings with running totals, and views that combine data across several databases - even across the boundary into a partner company's tenant - while every tenant only ever exposes what it could already read.

  • Governance for teams - access control, policies and admin-blind keys in Haven Enterprise

    Karsten Lehmann · July 11, 2026

    MindooDB has always protected your data by encryption - only people who hold the right key can read it. The new governance layer in Haven Enterprise (beta) adds the other half organisations need: rules about who may create, change or delete what, recorded in the same tamper-evident, append-only history as the data itself. Because every change is stamped with a trusted date the moment it reaches the server, those rules hold even when people work offline on devices whose clocks can't be taken at face value - and you can look back and answer 'who was allowed to do what, and when?' long after the fact. Haven Enterprise is in beta and is unlocked with a license key; Haven Community stays the free, keyless base everyone already knows.

  • A busy summer for MindooDB and Haven - everything new since May

    Karsten Lehmann · July 11, 2026

    A lot has happened since our last post at the end of May. Haven got a governance layer for organisations, instant search over encrypted data, full-text search with built-in text recognition for scanned paper, a one-click App Store, a new open-source drawing app, our most complete app yet in Mindoo Teacher's Desk, and a leaner, more real-time sync with a paper-based recovery kit. Here is the whole picture in one place, with a link to the deep dive on each.

  • Mindoo TeamEdit update - collaborative Word/.docx editing on MindooDB Haven

    Karsten Lehmann · May 25, 2026

    Mindoo TeamEdit gains a Word/.docx editing mode alongside the existing collaborative Markdown editor. Two people can now open the same .docx file in two TeamEdit instances, type into the same paragraph, drop in images, reshape a table, accept tracked changes, leave threaded comments - and watch the merged result appear on both screens through MindooDB's Automerge sync, with only the actually changed spans on the wire. TeamEdit also handles multiple documents open at once - a Window menu lists every open Markdown brief and Word memo and lets you flip between them. Under the hood the document is mapped to Automerge's rich text format (formatting spans plus block markers) on top of the EigenPal docx-editor we picked after evaluating SyncFusion and Apryse - chosen for its Apache 2.0 license, OOXML round-trip fidelity, and ProseMirror foundation that lets us plug in MindooDB's collaborative storage cleanly.

  • Mindoo TeamGrid update - virtual view sheets, 280 Excel formulas, charts and templates in MindooDB Haven

    Karsten Lehmann · May 21, 2026

    Four days after the initial release we are shipping a big round of updates to Mindoo TeamGrid, the collaborative spreadsheet for MindooDB Haven. The headline feature is Virtual View Sheets - pick any virtual view configured in Haven (including views that combine your private data with work data and with data from a partner company's tenant) and drop it into your workbook as a normal worksheet that Excel formulas, charts and XLSX export can read. Alongside it: a much larger formula engine with 280 Excel-compatible functions courtesy of fast-formula-parser, the four chart types Excel users actually use day to day (Column, Bar, Line, Pie), spreadsheet templates with File / New from template..., hidden rows and columns that survive an Excel round trip, automatic cell type detection from typed content, and a selection and keyboard model much closer to what people expect from Excel. And all of it still merges across two laptops, two devices, and four tabs the same way it did on day one.

  • How MindooDB stores attachments - encrypted chunks, append-only history, and on-the-fly MP4 streaming in Haven

    Karsten Lehmann · May 19, 2026

    Attachments in MindooDB are not stored as one blob hanging off a document. Each file is a chain of small encrypted chunks (256 KB by default, encrypted with the document's own key), and each chunk points back at its predecessor. The document only references the *last* chunk - which turns growing a file into appending one chunk, makes earlier document revisions automatically see only the bytes that existed then, and reduces moving or duplicating a large attachment between documents to copying a tiny JSON entry. Chunks are deduplicated by a hash of their encrypted bytes, so the same file inside one MindooDB database occupies storage once and syncs once. On top of all that, Haven streams long media attachments straight from those decrypted chunks - and for older MP4 files that browsers refuse to stream, Haven rebuilds them on the fly into a streamable shape with a lazy-loaded mp4box.js pipeline.

  • Document scanning in MindooDB Haven - turn any paper into an attachment with one button

    Karsten Lehmann · May 18, 2026

    Hold a phone over a piece of paper, press one button, and it lands inside the document you are working on - cropped, deskewed, rotated, and saved as a clean PDF or image. The new Scan document feature in MindooDB Haven is built on a custom, size-optimized OpenCV WebAssembly build that finds the page corners automatically and lets you nudge them by hand. Pick A4, Letter, a square or just keep the original aspect ratio, rotate in 90-degree steps, then Add to document - where it becomes a regular MindooDoc attachment - or, on iOS, iPadOS and desktop Safari, press Share file to hand the scan straight to the system Share Sheet without any upload at all. Available out of the box to every MindooDB app via the MindooDB App SDK.

  • Application time travel in MindooDB Haven - launch any app as it was at any moment in time

    Karsten Lehmann · May 17, 2026

    MindooDB Haven application registrations now carry an optional time travel date. Set it, launch the app, and every mapped database, every virtual view, every document and every attachment is served as it would have looked at that exact moment - read-only, all the way down to the historical attachment bytes. Duplicate the registration, pin two copies to two different dates, switch the runtime mode to 'Open in new window', and compare last sprint's plan against today's plan in two browser windows side by side. Audit, retrospective, regression debugging, and historical reporting - rendered in the real application UI, backed by MindooDB's signed, blockchain-style change history. Available out of the box for every MindooDB app running in Haven.

  • Mindoo TeamGrid - free collaborative spreadsheet editor for MindooDB Haven

    Karsten Lehmann · May 17, 2026

    Mindoo TeamGrid is a new sample app for MindooDB Haven that demonstrates how a spreadsheet workbook can be collaboratively edited across devices, with stable IDs that keep formulas valid through concurrent row and column changes, Excel import and export via file and clipboard, and a new granular JSON patch API in the MindooDB App SDK.

  • Mindoo TeamEdit - free collaborative markdown editor for MindooDB Haven

    Karsten Lehmann · April 30, 2026

    Mindoo TeamEdit is a new sample app for MindooDB Haven that demonstrates collaborative markdown editing built on the new text edit API in the MindooDB App SDK, alongside custom document IDs, undelete, and historical attachment access.

  • Haven - a peaceful, encrypted workspace built on MindooDB

    Karsten Lehmann · April 26, 2026

    Haven brings notes, files, apps, and data into one offline-ready team workspace, built on MindooDB so collaboration stays encrypted and under your control.