Show HN: Baby Vault – A 100% offline, privacy-first PWA for new parents | Hacker News Reader

Show HN: Baby Vault – A 100% offline, privacy-first PWA for new parents

babyvault.moshmage.com

5 pointsmoshmage4 comments

Looks great. I was a user of babybuddy[1] and one the pluses was that I could self-host and be in control + had an API. Now that last bit was a bit overkill.

It had one feature that's maybe essential and that I'm missing here, and that is being able to share the app and data with your partner so both are in control of monitoring, maybe I'm overlooking it but I can imagine that's hard to integrate with a PWA that does not use accounts.

One last thing: "no accounts", but filling in the email field is mandatory, i'd skip that.

Nice job!

[1] - https://github.com/babybuddy/babybuddy

The email is mandatory but you can input "no@no.no" - I placed it _before_ deciding i wouldn't make an account mandatory; Good catch, will be removed :)

For now, data sharing is via "export / import" (you can access it on the tools page) - It's not very robust, but I have yet to find a solution that doesn't involve me having a server receiving any kind of data (which is my north-star), I'm still exploring this as I ended up with the same problem as you: only I can control the data and my partner has to rely on me.

I'll send you a ping once I figure out a more robust and equally private way of sharing the data :)

ps: Thanks for the feedback!

Good news (everybody)! I’ve officially removed the email requirement and implemented a decentralized sync engine that keeps to my 'no-server' north star.

I ended up using Nostr as the backbone. Here is how it works now:

    No Accounts: Your identity is a cryptographic key pair generated locally. No emails, no passwords.

    Privacy-First Sync: When you want to share with a partner, you create a 'Vault.' This generates a shared secret key (NIP-44) that you share via a QR code.

    Decentralized: Data is encrypted on your device and synced via decentralized relays. Even the relay operators can't see your baby's logs—it's just gibberish to them.

    Self-Hosting Friendly: Since it uses Nostr, you can even point the app to your own private relay if you want 100% control over the infrastructure.

Thanks again for the push!

I became a father 11 days ago. By day 4, I was frustrated with the state of baby-tracking apps. Almost every popular option requires an account, syncs sensitive health data to a proprietary cloud, and monetizes through data-harvesting or aggressive subscriptions.

As a developer and a "privacy freak," I didn't want my child’s data on someone else's server. So, I spent my "paternity leave" build-phase (the nap windows) creating Baby Vault.

The Tech Stack:

    Frontend: Vite + React + TypeScript.

    Storage: Dexie.js (IndexedDB). Data stays in the browser and never touches a backend.

    UI: shadcn/ui with a heavy focus on "one-handed" mobile usability.

    Deployment: Self-hosted on my own Coolify instance. (considering adding as a service)

Why I built it this way: Most parents just need to answer three questions: "When did they last eat?", "Are they gaining weight?", and "How do I show this to a doctor?"

I’ve implemented features that I felt were missing from the "big" apps:

    The Golden Hour Overlap: A Gantt-style chart for multi-child households to find that elusive moment when everyone is asleep.

    Medical Export: A CSS-print-optimized report for 90-second pediatrician reviews.

    Witching Hour Heatmaps: Identifying patterns in evening fussiness.

Privacy/Data Sovereignty: There are no accounts. No analytics. No "Donate" button. You can export your entire database as JSON and import it elsewhere. If you "Add to Home Screen" (PWA), it works perfectly in a basement with zero signal.

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