Knowledge base Talking to people
Voice and video calls
Audio and video, set up over encrypted Nostr events and then carried directly between the devices taking part.
Placing a call
Open a private message or a group chat and use the phone or camera button in its header. Video calls request 720p from the camera; an audio call asks for no camera at all.
Calls are only ever placed inside an existing private conversation — there is no way to ring a stranger out of a public channel. The one way in from outside is a call link, and its host admits each person by hand.
Who may ring you at all is Accept Audio & Video Calls, under Settings › Privacy & Security. It is Enabled by default; Friends only silently ignores calls from everyone else, and Disabled ignores all of them.
Group calls
Group chats support group calls, with the same audio and video. Each participant connects directly to each other participant, so the bandwidth and CPU each device needs grows with the number of people on the call — there is no server in the middle mixing the streams, and small calls work considerably better than large ones.
Call links
A call link lets someone join a call without being in a conversation with you first. Calls, in the header, lists your links and makes new ones; a group's menu and a private message's menu make one for that chat and offer to post it there. You give the link a name, pick voice or video, and choose when it expires: after 1 hour, 24 hours, 7 days, or never.
Opening the link asks the person to confirm, then sends you an encrypted request to join. You admit or decline each request, so you need to be online, and the link does nothing while you are not. Revoke ends a link early, and anyone who tries it afterward is told it was revoked. Making or using a call link needs an identity that can send private messages, and the internet.
The link contains your public key, so anyone who holds it knows who is hosting. Once you admit someone, the call is a direct connection like any other, with the caveat below.
What a call reveals
Two different things happen during a call, with different privacy properties.
Signaling — the offers, answers and candidates that let two devices find each other — travels inside NIP-17 gift wraps, exactly like a private message. It is end-to-end encrypted and carries the same metadata protection.
Media — the audio and video itself — flows peer-to-peer over WebRTC, encrypted in transit, without touching a relay.
That is inherent to a direct connection, not something Nymchat adds. Where a direct route cannot be found — typically behind a symmetric NAT — the connection falls back to a public TURN relay instead, which forwards the encrypted media without being able to read it. The same applies to peer-to-peer file transfers. If your IP address is something you protect, do not take calls from people you would not give it to.