Joinstr

Version0.1.2-patch.1

Source codePublic

Compatible withumbrelOS 0.5 or later

Joinstr is a coordinator-less coinjoin that uses Nostr relays to find peers and collaboratively build a Bitcoin transaction, improving on-chain privacy.

The app runs the Joinstr web UI against your Umbrel's Bitcoin node, which it connects to automatically.

What's new

Version 0.1.2-patch.1+Sep 16, 2026

This update adds support for new storage management and configuration options being introduced with umbrelOS 2.0.

Previous Joinstr 0.1.2 release notes:

Fixes a bug where joining a pool showed a blank page and the join never completed. The credentials page had a malformed title tag, which made the browser render the page empty, and the pool creator stopped answering join requests after the first attempt, so retrying never worked.

Also a security release. A joiner now bounds what a coinjoin can cost it and will not sign a registration transaction that could be broadcast on its own, pool credentials are accepted only from the pool that was actually joined, pool announcements must be signed by the key they name, and nostr events are verified before use rather than trusted from the relay.

Version 0.1.2+Aug 14, 2026

Fixes a bug where joining a pool showed a blank page and the join never completed. The credentials page had a malformed title tag, which made the browser render the page empty, and the pool creator stopped answering join requests after the first attempt, so retrying never worked.

Also a security release. A joiner now bounds what a coinjoin can cost it and will not sign a registration transaction that could be broadcast on its own, pool credentials are accepted only from the pool that was actually joined, pool announcements must be signed by the key they name, and nostr events are verified before use rather than trusted from the relay.

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