Hosted Hearth: your private chat at yourname.hearthchat.net
· Updated 18 September 2026 · SparkBox team
Updated September 14, 2026 · Current setup guidance; early-access limits are stated where applicable.
Hosted Hearth is your own end-to-end-encrypted group chat, running at yourname.hearthchat.net — no hardware, no setup, ready about a minute after checkout. It's included for a year with SparkBox Ultimate, or available on its own ($5/month or $29.99/year). This guide covers claiming yours, inviting your people, the desktop app, what "sealed" encryption actually means, and your choices when the included year ends. Running Hearth on your own SparkBox instead? That's the Hearth on SparkBox guide.
1. What you're getting
Hearth is a private group chat — think of your family or friends group, minus the company in the middle. The hosted version runs on our servers so you don't need any hardware, but it runs sealed: messages, photos, videos, and voice notes are encrypted on your devices, and the key that unlocks them travels only inside your invites. What sits on our servers is scrambled data we cannot read. There are no ads and no data mining — the subscription is the entire business model.
No accounts either. People join your Hearth with an invite link, pick a display name, and they're in — no email sign-up, no phone number.
2. Claim your Hearth
After checkout — whether you bought hosted Hearth on its own or got it inside the Ultimate bundle — watch your email. Your Hearth is provisioned automatically and the email with your address and invite link lands in about a minute.
- Open the email (check spam if it hasn't shown up after a few minutes — it's the one mentioning hearthchat.net).
- Click your invite link. Your Hearth opens in the browser at your own address —
yourname.hearthchat.net. - Pick your display name. You're in, and you're the first one there — which makes you the admin.
Ultimate buyers: the Hearth email arrives separately from your SparkBox license email — the bundle's pieces each send their own. If it's been more than a few minutes and you have the license email but no Hearth email, see section 7.
3. Invite your people
Inside Hearth, tap 📨 Invite people in the left sidebar. It gives you a link and a QR code. Anyone who opens the link — or points a phone camera at the QR — picks a name and starts chatting. That link is the only key to your Hearth: treat it like a password and only share it with people you want in.
Because your Hearth is sealed, the invite link is also how the encryption key reaches your people's devices — that's by design, and it's why there's no "forgot password" flow. The link is the trust.
4. "Sealed" — what it means, honestly
Sealed means end-to-end encrypted: your devices scramble everything before it leaves, and only devices holding your invite key can unscramble it. Even we can't read your messages — and that's checkable, not a promise: the server only ever stores ciphertext.
Two honest trade-offs come with that:
- No link previews. The server can't read your messages, so it can't fetch previews for links in them.
- Search runs on your devices, not the server — for the same reason.
And three things sealing does not hide, so you are not surprised later:
- The shape of the chat. Names and profile photos, channel names, who posted when and replying to whom, reactions, and each file's name, type and size all sit on the server in the clear. It needs them to deliver your messages. The words and the file contents are what stay scrambled.
- The key never changes on its own. Removing someone from your Hearth changes the join code, not the encryption key. If they kept an invite link, they keep the key. A key reset is on the roadmap; until it ships, treat invite links like house keys.
- The web app's code comes from the server. In a browser or the desktop app, you run whatever Hearth we serve, so "we can't read it" rests on us serving honest code. The iPhone app carries its own code and only exchanges data with the server, which is a stronger guarantee. Calls are encrypted between your devices; the server relays the connection setup but cannot read the call.
If you'd rather trust no one at all — including us — that's what self-hosting is for: Hearth is free on every SparkBox, forever. See section 6.
5. The desktop app
There's a desktop app for Windows and Linux — grab it from tomsparkbox.com/hearthchat. Type your Hearth's address once and it remembers your servers, keeps you signed in, and updates itself. It works fully with sealed Hearths. On phones, Hearth installs as a web app straight from the browser — open your Hearth, and your phone will offer to add it to the home screen, push notifications included.
6. After your included year
If your hosted Hearth came with Ultimate, the first year is included (a $30 value). When it ends you have two good options and zero pressure:
- Keep it hosted — $29.99/year (or $5/month). Nothing changes; your address and history stay put.
- Move it to your SparkBox — free, forever. Hearth is included with every SparkBox, so if you're running one anyway, your chat can live on your own hardware at no cost. The Hearth on SparkBox guide walks through it.
Only the Hearth hosting ever renews in the Ultimate bundle — and only if you want it. Everything else in the bundle is one-time.
7. If something's off
No claim email after a few minutes (spam checked)? Open a private support ticket with the email address you used at checkout — support can match your purchase and re-send. The same goes for anything about your address, renewals, or moving between hosted and self-hosted. Don't post your checkout email or purchase details in the public community or a direct message; d/hearth is for redacted setup questions.
That's your hosted Hearth, claimed and yours.
If something doesn't match what you see, post in d/sparkbox — every stumble in this guide gets rewritten.
Everything about Hearth → More guides →
Check the invitation from the guest's point of view
Before sending your link to a large group, invite one trusted person using a different device. Confirm that they can reach the correct address, join, read a harmless test message and send a reply. Test a small attachment before assuming a long video will transfer reliably over a mobile connection.
The hosting claim or purchase link is for the owner; the chat invitation is for guests. Keep those separate. An encrypted conversation can still be read by a participant who was intentionally invited, so encryption does not make it safe to post the join link publicly.
If notifications matter, have the guest install the web app using the phone instructions, allow notifications and then lock the phone while you send a test message. Opening the chat in a browser tab and seeing a message arrive is not the same test as receiving an alert while the phone is locked.
Plan a move before the included year ends
Ultimate includes the first year of hosted Hearth. Continued hosting is currently listed at $29.99 per year; using Hearth on your own SparkBox remains free apart from your own hardware, connectivity and storage. Review the actual renewal terms in your hosting account rather than assuming a lifetime Ultimate purchase means lifetime rented hosting.
Changing to self-hosting means changing the server that holds the conversation. Before shutting down the old service, identify the supported backup or migration path, preserve the owner's recovery material and test the new installation with a small group. Simply installing another Hearth container does not prove existing history and uploads migrated.
For setup and migration questions use d/hearth. Include hosted versus self-hosted mode, device/browser, whether ordinary messages work and what fails. Share purchase identifiers only through private support. Do not attach join links, recovery material or private chat exports to the public thread.
Questions, or did this not match your box?
Every guide here came from a real problem someone hit. If yours behaves differently, say so — that is how these get corrected, and how the fix gets prioritised.
We answer there rather than in a comment box, because that is where the people who have already solved it are.