No account. No phone number. No email.
Inside Tact-VC, you aren't a row in someone's database. Your identity is a key that's made on your computer and never leaves it.
Nº 01Gehlvora catalogueBeta
Tact-VC
Talk to your friends.Nobody else listens.
Private voice calls, straight from your computer to theirs. End-to-end encrypted. Peer to peer. No servers in between: not ours, not anyone's.
- macOS
- Windows
- Linux · soon
01The route
Most calls take a detour.
Most voice apps send every word you say through a company's servers. Even when they're encrypted, someone else decides who you are, keeps your contact list, and knows when and with whom you talk.
Tact-VC takes the straight line.
There's no server to route through. A call involves your computer, your friend's computer and your two internet providers. That's it.
- Nobody can hand over your call history. It doesn't exist anywhere.
- Nobody can read your friend list. It lives only on your device.
- No outage can stop your calls. There's no service to go down.
Sealed at both ends.
Your providers carry the packets, but all they see is noise. Every call is end-to-end encrypted with the Noise protocol, the same design family as WireGuard.
Keys are thrown away and renewed every 10 minutes, so even a stolen key can't open yesterday's call.
Route of one callParties 5 · Servers 1
Every word passes the server0%
02Your key
- Sign-up formSkipped
- Phone numberNot asked
- Password resetNothing to reset
Adding a friend3 steps · no server
01 Make your key
A key pair is generated on your computer. Your picture of it is your fingerprint.
02 Share your code
Send your friend code however you like: a chat, an email, a note on paper.
03 Compare fingerprints
Same picture on both screens? Then nobody swapped the code on its way.
Who can reach you
Strangers can knock. Only friends can call.
| Friend request | Call you | |
|---|---|---|
| Stranger | Can send | Blocked |
| Friend | Already in | Can call |
New computer? Save an encrypted backup of your key, name, picture and friends, protected by your passphrase, and take it with you.
03Your voice
Sound like you. Not like your keyboard.
Tact-VC cleans your voice before it leaves your computer. Full-band Opus audio, echo cancellation, noise suppression and automatic volume are all built in.
Your microphone
Your words Fans, keys, music
Silence between words stays silent
Opus · full band · 64 kbit/s (32 or 96 selectable) · noise suppression in three levels
Echo cancellation
Use your speakers. Your friends won't hear themselves coming back.
Automatic volume
Whisper or shout, you arrive at the same comfortable level.
Jitter buffer
Shaky Wi-Fi? Late packets are put back in order, lost ones are recovered.
Written in Rust
Built in a memory-safe language, and light on your computer.
04Group calls
One group call1 people · 0 direct links
You start a callNo host
Up to six friends. Everyone connected to everyone.
In a group call, every computer talks directly to every other one. There's no host in the middle, so anyone can leave and the call carries on for the rest.
- Add people mid-call. They're introduced and connect by themselves.
- Mute, deafen, and see live connection stats for each person.
- A text chat that lives exactly as long as the call. Hang up, and it's gone.
05The app
Calm, on purpose.
Two inks, sharp lines and pixel pictures, like a page of paper. Nothing blinks for attention. Here's the real thing.
HomeYour friends as a row of cards. Ada is calling, with Bo already in.
Group callSix tiles, one per person. Farah is connecting, Cyrus is still ringing.
ChatThe in-call chat. It disappears when the call ends.
06Connecting
Through the router, no helpers needed.
Tact-VC finds its own way through. It asks your router to open a door, uses IPv6 where it can, and punches holes where it can't. No third-party connection helpers.
A built-in network check tells you in plain language whether you're reachable, and how to fix it if you aren't. On your local network, it works with no setup at all.
Hole punchingBoth knock at once
UPnP · NAT-PMP · IPv6 · Hole punching · LAN
07Privacy
Nothing reaches us.
The app doesn't phone home. We couldn't hand out your calls, your friends or your history even if we wanted to. We never have them. Your friends' computers do see your IP address, as with any direct connection.
- TelemetryNone
- Call historyNot kept
- RecordingsNever
Security, in detailFor the curious
- Protocol
- Noise IK_25519_ChaChaPoly_BLAKE2s
- Authentication
- Mutual, by public key, in the first round trip
- Forward secrecy
- Ephemeral keys, re-keyed every 10 minutes
- Replay protection
- Handshake timestamps + 1024-packet window
- Identity
- Curve25519 key pair, made locally, never leaves your device
- Backups
- Argon2id + ChaCha20-Poly1305
- Written in
- Rust
Need help? Tact-VC can save a diagnostic report to your disk. You see it first, IP addresses are masked by default, and you decide who gets it.
08Beta
Beta means it works. Now it meets the real world.
Tact-VC is fully usable today. What we don't know yet is your living room: your router, your headset, the friend with the strange Wi-Fi. The beta is where we learn from those first real calls and make it better with every update.
Updates are included in your purchase. Available in English and German, with light and dark themes.
- macOSAvailable
- WindowsAvailable
- LinuxComing soon
Made for everyone
Full keyboard navigation, screen-reader labels and announcements, high contrast..
System requirements
| macOS | Windows | |
|---|---|---|
| System | macOS 11 Big Sur or later | Windows 10 (21H2) or 11, 64-bit |
| Hardware | Any Apple silicon Mac (M1 or later). No Intel Macs. | x86-64 (Intel or AMD), dual-core 2 GHz with SSE4.1. No ARM. |
| Memory | 8 GB | 4 GB, 8 GB recommended |
| Disk space | 200 MB | 200 MB |
| Display | 1280 × 800 | 1280 × 720 |
| Permissions | Microphone and local network access | Administrator rights to install (adds a firewall rule), microphone access |
- Audio: any microphone and speakers or headset. Echo cancellation handles laptop speakers. Bluetooth headsets sound better with the built-in mic as input.
- Internet: about 100 kbit/s up and down for every other person in the call, under 150 ms latency. Wired or stable 5 GHz Wi-Fi is best.
- Router: UPnP or NAT-PMP, or one UDP port forwarded by hand. Works best with a public IPv4 address or IPv6. Made for home networks; school or work networks may block direct calls.
- License: internet access to our license server at least once every 7 days.
Opening an unsigned app. Tact-VC isn't code-signed yet. Signing certificates are expensive, and while Tact-VC is a young beta we keep costs low. Your system will warn you the first time, so here's how to open it anyway:
- macOS: open Tact-VC once and close the warning. Then go to System Settings → Privacy & Security, scroll down and click “Open Anyway” next to Tact-VC. Confirm with your password.
- Windows: when SmartScreen shows “Windows protected your PC”, click “More info”, then “Run anyway”.
Beta: processor, memory and disk figures are estimates.
?Questions
Is it really free of servers?
Yes, for calls. Voice, chat and friend requests travel directly between computers. The only server is our license check, which the app contacts about every 6 hours.
Do I need an account?
You need a Gehlvora account to get your license key. Inside the app there is no account: your identity is a key on your own computer.
Can Gehlvora listen to my calls?
No. Calls never pass through us, and they're end-to-end encrypted.
Does Tact-VC record calls or keep a history?
No. Tact-VC doesn't record calls or keep a history. Like with any call, people in it could still record it with other tools.
What happens if Gehlvora disappears?
We'd announce a shutdown at least 3 months ahead by email. Because the app needs our license server at least once every 7 days, it stops working 7 days after a shutdown, unless we ship a version without the license check first. Your calls never depended on us.
My friend can't connect. What now?
Open Settings → Network → Check my network. It explains what's blocking you and how to fix it on your router.
→Get Tact-VC
Your conversations. Your computers. Nobody in between.
Tact-VC · Beta
5€
Once. No subscription.
- Tact-VC, and the whole Gehlvora catalogue, including future software and updates.
- Up to two keys per software, for your own private use.
Sales start soon. Terms of Service · Right of Withdrawal