Frequently Asked Questions

SemaBuzz is a live character-by-character chat app for Windows. Every letter you type streams to the other person in real time — no send button, no waiting. Download it free from the Microsoft Store.

No. SemaBuzz requires no sign-up, no email, and no password. You start a session, share a code, and chat.

The Standard tier is included with the app purchase on the Microsoft Store. Pro features such as extra themes, advanced indicator styles, custom relay support, and a custom default listen port are available as an in-app upgrade.

SemaBuzz is 1:1 only — just you and one other person. No group chats, no noise.

Your messages are encrypted on your device using ECDH P-256 key exchange and AES-256-GCM before they leave your machine. SemaBuzz tries to establish a direct peer-to-peer UDP connection first — if that succeeds, your traffic never touches the relay server at all. If a direct path isn't possible, the relay is used as a fallback tunnel, but it only forwards ciphertext it cannot read. No messages are stored on any server.

Messages are always encrypted in transit. On most home networks SemaBuzz connects directly peer-to-peer — the relay isn't in the data path at all. On restricted networks the relay forwards ciphertext it cannot decrypt. Either way, the key exchange is unauthenticated — SemaBuzz cannot verify who you're chatting with. Only share your invite code with people you trust.

SemaBuzz uses a relay server to let the two peers find each other. Once connected, it immediately tries to establish a direct peer-to-peer UDP link using STUN hole-punching. If that succeeds — which it does on most home and office networks — the relay drops out and your traffic flows directly between the two machines. If a direct path isn't possible, the relay stays as an encrypted tunnel.

STUN (Session Traversal Utilities for NAT) is a standard technique used by video-call and VoIP apps to punch through NAT routers and firewalls so two devices can talk directly. Each peer asks a public STUN server what their external IP:port looks like, then both send UDP packets at each other simultaneously to open a path through both routers. SemaBuzz does this automatically every time you connect.

If both peers are behind symmetric NAT, CGNAT, or a firewall that blocks UDP, hole-punching can't succeed and the relay serves as a fallback tunnel. All traffic through the relay is still encrypted end-to-end with AES-256-GCM — the relay only ever sees ciphertext.

The status bar in the Windows app shows the connection path. "Direct UDP" means the relay dropped out and you're peer-to-peer. "Relay" means traffic is going through the relay server as a fallback.

Yes. In Settings you can point SemaBuzz at any compatible relay server.

The Windows app is available on the Microsoft Store. Search for "SemaBuzz" or follow the link at the top of this page.

As a native app, SemaBuzz integrates with your system: taskbar presence, native notifications, buzz:// URI scheme so peers can send you a direct dial-in link, avatar and display name support, the built-in Obsidian theme, and Pro upgrades like extra themes, advanced indicators, and custom relay support.

Buzz shakes the other person's window with a quick animation to grab their attention — useful when they've gone quiet.

No. SemaBuzz is intentionally session-only. When the session ends, the conversation is gone.

The filament is a live waveform that pulses as the other person types. Pro unlocks Pulse and Wave styles in addition to the default Flicker.

When someone dials your session token, a prompt appears for you to Accept or Deny. Accept lets them in; Deny sends them a polite "not available" notice. Your session, your call.

The Windows app requires Windows 10 (version 1803 or later) or Windows 11.