commoncall#

Serverless peer-to-peer video calls in the browser.

Live page: https://concept-collection.github.io/commoncall/

Visit the page, enter an ID, and you'll see the IDs of everyone else currently on the page. Click a visitor to request a call; once they accept — both users must agree — a direct WebRTC connection is established and audio/video flows peer-to-peer. During a call you can share your screen in place of your camera.

How it works#

There is no backend. The techniques are the same as the sibling project commonview:

• Identity — each browser generates a secp256k1 (BIP340 schnorr) keypair, persisted in localStorage. The x-only public key is the peer ID, and every message is signed with it, so peers can't be impersonated.
• Presence & signaling over nostr — a minimal nostr client (modeled on trystero's nostr strategy) publishes ephemeral events to a handful of public relays. Everyone announces {peerId, name, busy} on a shared root topic every few seconds; entries expire when announcements stop. Call requests, accept/decline, and WebRTC offer/answer/ICE messages are delivered on a per-peer topic derived from the recipient's ID.
• Mutual consent — clicking "Call" only publishes a call-request. Neither side touches the camera or opens a WebRTC connection until the callee explicitly accepts.
• WebRTC media — after acceptance, the peer with the smaller ID creates the offer (deterministic initiator, no glare handling needed). Audio and video tracks flow directly between the browsers, with public STUN servers and a free TURN relay as fallback for hard NATs.

Development#

npm install
npm run dev

Open the page in two browsers (or one normal + one private window — identity is per-browser-profile) and call yourself.

npm run build type-checks and bundles to dist/. Pushes to main deploy to GitHub Pages via .github/workflows/deploy.yml.