Ethereum co-founder Vitalik Buterin released a working demo of an anonymous message board on Aztec Sunday. He shared the project on Farcaster, describing it as a "vibe-coded" toy version of the "anon billboard with moderation" concept he outlined in a 2022 blog post. The demo implements fully private posting paired with an onchain moderation layer on the Aztec Layer 2 network. The code is publicly available on GitHub under Buterin's vbuterin account. The project addresses privacy and content moderation challenges in decentralized communication systems by combining anonymous posting with programmable censorship rules.
Technical Architecture on Aztec Layer 2
The message board is built on Aztec. Users deposit ETH on Ethereum's base layer, post messages anonymously on Layer 2, and later withdraw their ETH back to Layer 1, according to the repository. Posts carry no sender address in public call data and no link to the original deposit.
Buterin noted in a follow-up cast on Farcaster that Aztec had reached stage 2, the most decentralized tier on the Layer 2 maturity scale.
Onchain Moderation System with LLM Daemon
The design attaches a censor role, set at deployment, that can flag posts as "immoral." Flagged posts are hidden from the default feed and impose a time-lock penalty on the poster's next message.
A local LLM daemon watches the board, evaluates each post against an onchain moderation policy, and flags anything that violates it, per the documentation. The policy itself is stored onchain and readable by the app, the CLI, and the daemon.
Rate Limiting and Formal Verification
Posting is rate-limited through a cooldown that shrinks as the deposit grows. According to the repository, 0.001 ETH buys one post per hour, while 0.01 ETH buys ten posts per hour.
Part of the system carries formal verification. The security properties covering rate limits, censorship screening, privacy, and deposit safety are proven in Lean 4 across 70 theorems with zero unproven gaps, the documentation said.
Development Status and Open Items
The repository lists the work as early and incomplete, with open items including access-control fixes and untested browser flows. Buterin said in his cast that the demo can already do "very interesting nontrivial stuff."
FAQ
What does Vitalik Buterin's anonymous message board demo do?
The demo allows users to post messages anonymously on Aztec Layer 2 after depositing ETH on Ethereum's base layer. Posts carry no sender address in public call data and include an onchain moderation system that flags rule-violating content using a local LLM daemon.
How does the moderation system work in Buterin's message board?
A censor role set at deployment can flag posts as "immoral." A local LLM daemon evaluates each post against an onchain moderation policy and flags violations. Flagged posts are hidden from the default feed and impose a time-lock penalty on the poster's next message.
What is the current development status of the project?
The repository lists the work as early and incomplete. Open items include access-control fixes and untested browser flows. The system includes formal verification in Lean 4 with 70 theorems covering security properties for rate limits, censorship screening, privacy, and deposit safety.
