Block, the payments company led by Jack Dorsey, has launched Buzz, a free and open source platform designed for employees and AI agents to work in the same shared workspace, the company said Tuesday.

Built on the Nostr protocol, Buzz combines team chat, code repositories and automated workflows in one interface. The platform gives every human user and every AI agent its own cryptographic identity, and is designed to be model-agnostic, supporting agents built on Anthropic's Claude Code, OpenAI's Codex and Block's own goose framework.

Dorsey announced the launch on X, describing Buzz as “a new groupchat platform for teams of people and agents of all sizes” that was built to reduce Block's dependence on Slack and GitHub. He called the platform “model-agnostic, decentralized, self-sovereign, and open source.”

we're launching BUZZ! a new groupchat platform for teams of people and agents of all sizes, built to reduce our dependency on slack and github. model-agnostic, decentralized, self-sovereign, and open source. 🐝 — jack (@jack) July 21, 2026

Buzz includes channels, threads, direct messages, voice, media sharing, code repositories and automated workflows inside a single product. Block said the interface should feel familiar to anyone who has used a modern workplace chat tool.

Agents with cryptographic identities

AI agents in Buzz have their own cryptographic identities and defined permissions. They can post messages, review code, run approved automations and participate in conversations alongside human users. Multiple people and multiple agents can share the same workspace and build on one another's work.

The design addresses a practical issue for companies experimenting with software agents: if non-human participants can change code, trigger workflows or approve tasks, teams need a way to identify which actor did what and under which permissions.

“Every company is going to need a place where humans and agents work together,” Bradley Axen, Block's head of AI capabilities, said in a statement. “The question is whether that place is proprietary or open.”

Buzz is both model-agnostic and agent-agnostic. Teams can deploy agents powered by any large language model or harness, including Anthropic's Claude Code, OpenAI's Codex and goose, the open source agent framework Block first released in January 2025.

Why Block chose Nostr

Block said it chose Nostr to address what it considers the “most fundamental problem” in multi-agent work: identity. In Buzz, every participant, whether a person or an agent, holds a keypair that belongs to that participant rather than to the platform. As a result, an agent's identity, history and reputation can move across any Nostr-compatible system.

Nostr is built around signed events distributed through relays rather than accounts controlled by a single service, which aligns with Block's claim that Buzz identities should be portable across compatible systems.

According to the project's repository, each message, reaction, workflow step, review approval and git event is recorded as a single signed event in one log. The repository describes a hash-chain audit trail that applies whether the author is a person or a process.

The Buzz code is published under an Apache 2.0 license at github.com/block/buzz. Teams can self-host the software or use Block's managed version. The project remains early, shipping as version 0.4.21 with desktop builds for macOS, Windows and Linux, while mobile clients are still unfinished. Despite the project's “decentralized” framing, each workspace runs on a single relay, which the repository describes as its “single source of truth.”

Rethinking the operating model

Block employees have also been discussing how teams should work when the collaboration tool no longer determines the process. Lucas Isaza, who works on AI and product at Block, argued in a thread that tools such as Asana, Jira and Linear once embedded sprints and Kanban into company rituals, shaping the operating model as much as the work itself.

A configurable workspace removes those constraints, Isaza said, meaning “the bottleneck becomes the operating model.” In Buzz, he wrote, one thread can contain the diagnosis, task, fix and surrounding discussion, consolidating material that previously spanned several tools into a single record of why a decision was made.

— Lucas (@IsazaLucas) July 21, 2026

Agents can take user-level actions through CLI commands, create their own channels and update their own memories, while users can set channel- or thread-specific rules for each agent. Isaza said he had experimented with agents that generate a shared whiteboard for every thread, creating “better context handoffs with no additional work.”

Block has tested the approach internally for months and has “yet to figure out” the model that gets the most from Buzz, Isaza added. He noted that most work is collaborative and said “that doesn't need to stop with AI.”

Block built the Buzz platform itself using agents, according to Thomas Petersen, a principal designer and AI strategist at the company. Petersen said he rejoined Block wanting to change “the lonely experience of working with AI agents.” He added that “the entire platform” was developed using agents, including its interface, which he described as “more sculpted over time than designed up front.”

Dorsey's open protocol push

Buzz extends the open protocol focus that has shaped Dorsey's work since he left Twitter. He stepped away from the Bluesky board in 2024 and has since backed a series of tools that no single company controls, many of them built on Nostr, the relay-based protocol he has personally funded.

Those projects include Bitchat, Dorsey's Bluetooth mesh messenger, which China ordered pulled from Apple's App Store in April. The move echoed Beijing's 2023 ban on Damus, a Nostr-based Twitter alternative. Dorsey has also seeded andOtherStuff, a nonprofit focused on open source social tools.

Block cut more than 4,000 jobs in February, representing roughly 40% of staff. Dorsey said at the time that AI “fundamentally changes what it means to build and run a company.” One month later, he announced that Block's Cash App would add support for stablecoins into its core payment flow, though Dorsey, a Bitcoin maximalist, was public about his reluctance to do so. In April, Block disclosed holdings of 28,355 BTC worth $2.2 billion in its proof-of-reserves report.