Cast spells, not tweets. SpellCast is a Twitter-like social app with no servers, no sign-ups, and no company in the middle. Your messages (called "spells") travel directly between you and the people you connect with, and everything lives in your own browser. It's a single web page - nothing to install.
⚠️ SpellCast is an early prototype. It's a genuinely working, fun way to explore serverless social messaging - just don't rely on it for anything safety-critical yet. The honest details are in the technical notes.
Try SpellCast: sience.github.io/ - or run your own copy.
Most social apps are free because you are the product. SpellCast takes the opposite approach:
- No servers, no middleman. There's no company database holding your posts. Messages go peer-to-peer, straight between browsers - nothing central to hack, sell, or shut down.
- No sign-up, ever. No email, no phone number, no password. You pick a username, get an ID, and you're in.
- Your data stays with you. Posts, images, and contacts live in your browser - not in someone else's cloud.
- Private by design. No ads, no tracking, no profiling. Connections are encrypted in transit (WebRTC/DTLS), and messages only travel to people in your own network.
- Works everywhere. Any modern desktop or mobile browser - iPhone, iPad, Android, laptop. Connect with a friend in seconds by scanning a QR code.
- It even works offline. Write now; your spells send themselves when you reconnect.
- Cast spells - short posts shared instantly with everyone you're connected to
- Spark ✨ - cast a sparkle onto someone else's spell to show some love (a signed, peer-to-peer reaction)
- Images & links - attach a picture (large photos are automatically optimized to send), or drop a link and get an automatic preview (images, YouTube, websites)
- Circles - group your peers (Friends, Work, Family…), filter your feed by circle, and cast to just one group when you want to
- Mesh delivery - messages hop from friend to friend, reaching people you're not directly connected to
- Pick up anywhere - log back in on another device and your history syncs back from your peers
- QR connect - show your code, scan a friend's, and you're talking
- Click Create New Credentials
- Choose a username others will see
- Click Generate Your Credentials - you'll get a peer ID (your address on the network)
- Keep that ID somewhere safe - it's how you log back in
- Click Continue to App
- By QR code: show your code from the Profile tab and have a friend point their phone camera at it — it opens SpellCast and offers to connect. Or use the Scan QR button on the Connect tab to scan theirs from inside the app.
- By invite link: from the Profile tab, tap Share invite link (or Copy link) and send it over any messenger — opening it connects them to you. No typing required.
- By ID / link: open the Connect tab and paste a peer ID or an invite link, then click Connect.
- SpellCast remembers your connections and reconnects automatically next time
- In the Feed, type your message (add an image or a link if you like)
- Press Cast - it's shared with your connected peers and appears in your feed
- The little "Casting to" label shows where it'll go - everyone, or the circle you've selected
Circles are your own private groups of peers - like lists.
- Create a circle from the sidebar (+) or the Circles tab
- In the Circles tab, add or remove peers
- Click a circle in the sidebar to filter your feed to just those people
- While a circle is selected, your casts go to that circle - pick All Peers to post to everyone
On the Profile tab you can show your QR code, Clean Up Storage (remove unused images and stale data), Delete All Messages, or Delete Credentials to wipe everything and start fresh.
SpellCast is an honest prototype, so a few things are worth understanding up front:
- Identities are cryptographically signed. Every message is signed with a key that lives only in your browser, and your peers verify it - so impostors can't forge your posts (a key/name mismatch is flagged as "⚠ impersonator?"). Your displayed handle is
name#fingerprint. Back up your key from Profile → Export Credential Backup (passphrase-encrypted) and restore it on another device from the login screen. - Your peer ID is still your network address and login for now; moving your credentials to another device is done via the encrypted credential backup — either the backup file, or Profile → Show Backup QR and Login → Scan Backup QR on the new device — rather than re-typing the ID.
- Connections are encrypted in transit (WebRTC/DTLS). Circle posts are additionally end-to-end encrypted to each member's key - the broker and any intermediary only see ciphertext. Public ("All Peers") posts are not encrypted, since they're meant to spread across the whole mesh.
- Metadata isn't fully private: by default a public PeerJS broker can see peer IDs and who connects to whom (not your message content). You can self-host the broker + TURN to keep that off third-party servers.
- Deleting a message removes it from your device; copies others already received may reappear when you reconnect.
The full, frank list is in the technical notes.
SpellCast is vanilla JavaScript with no build step. The architecture, networking internals, storage model, how to run it locally, and contribution guidelines all live in docs/TECHNICAL.md.
Creative Commons Attribution-NonCommercial 4.0 International - see LICENSE.
- Share and adapt freely, with credit
- Indicate any changes you make
- Non-commercial use only
Cast spells, not tweets. Be decentralized.