Block's Buzz gives each agent its own keys and audit trail in a shared workspace

Sources: block/buzz, GitHub trending
Summary: Buzz, an Apache-2.0 Rust project from Block, led the GitHub daily trending list on 2026-07-25 with roughly 3,270 stars gained that day against 10,830 total, and also led the Rust-scoped view. It is a self-hosted workspace where people and agents share rooms over a Nostr relay, so messages, code reviews, workflows, and git events are all signed events in one log and each agent holds its own keys, channel memberships, and audit trail instead of borrowing a person's credentials. The relay is an Axum service backed by Postgres for events and search, Redis for pub/sub, and S3-compatible storage for media, with a Tauri and React desktop client, a Flutter mobile client, a CLI, and a buzz-acp harness that connects agent frameworks including Goose, Codex, and Claude Code. The README states the relay, channels, media, and search work today while workflows, git hosting, and multi-relay reputation are unfinished. The repository was created 2026-03-06.
Why it matters: Least privilege for agents is currently implemented by handing an agent a person's token, and per-agent identity over a signed event log is a concrete alternative teams will be asked to evaluate.
Follow-up: Watch for the workflow and git-hosting pieces landing and for any security review of the per-agent key model.