Buzz!
**Block** announcement from **July 21, 2026**, signed by **Tyler Longwell**: **Buzz**, an *open source* and **self-hostable** channel-driven workspace where humans and agents share the same room — chat, search, automation, and **Git hosting** on a single server, built on **Nostr**, an open protocol for signed messages and portable identities. Opening thesis: *« Models can do the work now. Teams still need somewhere to do it together. The bottleneck moved from intelligence to coordination. »* Three engineering pieces. **(A) Agent identity.** The starting point is a refusal — to stop lending one's credentials to a bot: *« We have been letting bots play dress-up as us. It's weird. It's dangerous. »* Each agent gets **its own key**, its owner signs a **narrowly scoped authorization**, and the agent then signs its work with its own identity. The delegation cryptography is conventional; the design decision is less so: *« authorization does not erase authorship »* — the agent remains the author, its *credential* proving who authorized it and under what conditions. Immediate consequences: a leaked agent key is revoked without touching the human identity, and withdrawing the owner prevents the agent from reconnecting, with its active sessions needing to be terminated separately. **(B) Git on object storage.** The observation: *« In the past, Git has always had a convenient rate limiter: humans »* — a group of agents produces months of person-commits and CI in a single afternoon, with many simultaneous writers, on forges sized for human fingers. Buzz stores repositories as **immutable, content-addressed packfiles** plus a **single mutable manifest pointer**; a *push* writes the objects first, then advances the pointer via **conditional compare-and-swap**, that swap being the commit point — workspace events announce the change, they do not define it. The protocol is **specified in TLA+ and model-checked** (durability, reconstruction, concurrent pushes), with the bounded result depending on three explicit object-store guarantees, hence a **conformance suite** every backend must pass. **(C) Interoperability and privacy.** Claude Code, Codex, goose *« and any agent speaking Agent Client Protocol »* work inside Buzz; switching model or harness leaves the project's identity, permissions, and history intact. Telemetry and cancellation travel as ephemeral encrypted messages, memory and cost accounting as durable encrypted messages — *« the server sees routing metadata, not those payloads »*. Memory argument: *« A conventional forge preserves the diff and a green check. Buzz also preserves why the obvious fix was wrong. »* Anti-lock-in argument: if Buzz disappears, the identity and signed history remain verifiable, Git stays Git.
**Tyler Longwell** — *« Building multi-player AI at Block »* · auteur unique et signataire à la première personne. Publié le **21 juillet 2026** sur le blog Block Engineering.