Image: reddit.com · Built a post-quantum I2P messenger with Claude Code: 1:1 OTRv4+, MLS+ group chats, voice calls, and a monitor for the server. Protocol v2 just shipped (+ means
A post-quantum I2P messenger built with Claude Code
OTRv4+ is an end-to-end encrypted messenger over I2P, with Claude implementing the poster's designed protocol steps and writing tests.
The full story
OTRv4+ is an end-to-end encrypted messenger over I2P with Android and desktop clients, 1:1 chat, MLS group chats, voice calls and file transfer. The poster made the architecture decisions and used Claude Code for research and implementation in Rust and Kotlin.
The poster wrote the order of operations for the handshake, Claude implemented it and wrote known-answer tests, and every bug got a regression test. An internal review of the Rust core, labelled as not an external audit, found issues such as ring-signature nonce reuse and the ratchet committing before authenticating; each fix has a test.
How it was done
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From a short post by the maker, so the details are as they tell them.
- Reddit: Built a post-quantum I2P messenger with Claude Code: 1:1 OTRv4+, MLS+ group chats, voice calls, and
The maker's post on r/ClaudeCode.
The poster has deleted it, but the original is still readable (it can take a few seconds to load): archived copy of Reddit: Built a post-quantum I2P messenger with Claude Code: 1:1 OTRv4+, MLS+ group chats, voice calls, and (opens in a new tab)