TL;DR
- Buterin published a functional demo of an anonymous message board on Aztec, where users deposit ETH and post without exposing their address.
- The system incorporates a configured censorship role and a local LLM daemon that moderates content according to a policy stored onchain.
- The project’s security properties are formally verified in Lean 4 with 70 theorems and no unproven gaps.
Vitalik Buterin presented a functional demo of an anonymous message board built on Aztec, combining private posting with an onchain moderation system.
The Ethereum co-founder shared the project on Farcaster and described it as a “vibe-coded” version of the concept he had outlined in a 2022 blog post. The code is publicly available on GitHub under his vbuterin account.
Vibe-coded a toy demo version of the "anon billboard with moderation" idea from https://t.co/fheLOlfF3F on aztechttps://t.co/iIkwH3UbO4
It's early days but you can already do very interesting nontrivial stuff! pic.twitter.com/NbfrBJ4FtU
— vitalik.eth (@VitalikButerin) July 19, 2026
How Does the Message Board Presented by Buterin Work?
The mechanism works as follows: users deposit ETH on Ethereum’s base layer, post messages anonymously on Layer 2, and then withdraw their funds back to Layer 1. Messages do not expose the sender’s address in public call data or record any link to the original deposit. In his follow-up post, Buterin also noted that Aztec had reached stage 2, the highest level of decentralization within the maturity scale for Layer 2 networks.
This design incorporates a censorship role defined at deployment, with the ability to flag posts as “immoral”. Flagged posts remain hidden from the default feed and generate a temporary lock penalty on the user’s next message. A local LLM daemon monitors the board, evaluates each post against a moderation policy stored onchain, and flags any content that violates it. Both the application and the command-line interface and the daemon can read that policy directly.
Formal Verification and Next Steps
The system also implements a posting frequency limit via a cooldown that decreases as the deposit grows: 0.001 ETH allows one post per hour, while 0.01 ETH allows around ten. The security properties covering frequency limits, privacy, moderation, and fund custody were formally proven in Lean 4 with 70 theorems and no unproven gaps.
The repository classifies the work as incomplete, with pending items that include access control fixes and untested browser flows. Nevertheless, Buterin stated that the demo can already do “very interesting and non-trivial things”.
