0xchat

0xchat is a chat-first nostr client built by water783. It runs on iOS, Android, and desktop (macOS, Windows, Linux), with a tablet-optimized layout. Features include one-to-one encrypted DMs, private and public groups, channels, voice notes, and audio/video calls that ring and show up in the call log like a native phone call on both iOS and Android. Call signaling goes over nostr relays and media streams through servers the user picks, so there is no central operator in the path.

0xchat supports multiple DM formats: the older NIP-04 encrypted messages, the sealed-sender and gift-wrapped format from NIP-17 and NIP-59, and a secret chat mode. It was also the first nostr client to ship NIP-29 relay-managed groups. Because these formats are the same ones other clients implement, 0xchat users can carry DM threads with people on Amethyst, Damus, Coop, Flotilla, and noStrudel without leaving their preferred app.

Lightning zaps, a built-in Cashu wallet for ecash, and Nostr Wallet Connect for balances and payments all live inside the app, and NIP-46 remote signing works with Amber, nsec.app, Aegis, and Nowser. A built-in Tor client (via arti) lets the app talk to onion relays and Cashu mints directly, and a Discover tab exposes "NApps" (third-party nostr web apps) through NIP-07.

Why fund it?

Encrypted messaging is one of the few nostr use cases that can realistically replace Signal or WhatsApp for everyday users. Getting there needs a mobile client that handles group chats, calls, and onboarding without rough edges. 0xchat is also one of the earliest clients to ship new DM standards, which pulls the rest of the ecosystem toward interoperable private messaging.

OpenSats first funded 0xchat in the second wave of nostr grants in October 2023 and has renewed the grant multiple times, most recently in the thirteenth wave.

What's next?

The project now ships two apps in parallel. The main 0xchat client keeps adding features (Posts with Markdown, global feeds, translation via LibreTranslate and Google ML Kit, NApps). A smaller sibling, XChat (formerly "0xChat Lite"), focuses on native iOS and Android UIs and MLS-based "Circles" with their own relays, storage, and file servers.

Upcoming work covers disappearing messages, Cashu wallet upgrades for more NUTs, NIP-61 Nutzaps, NIP-29 invite codes, and a BitChat integration that relays messages over Bluetooth Low Energy mesh. The team ships regularly to the iOS App Store, Google Play, Zapstore, and F-Droid.