Block has launched Buzz, a free and open-source platform where employees and AI agents work side by side inside a shared workspace, the company said Tuesday.
Jack Dorsey announced the product on X, calling Buzz “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 described it as “model-agnostic, decentralized, self-sovereign, and open source.”
One workspace for chat, code, and workflows
Buzz combines channels, threads, direct messages, voice, media sharing, code repositories, and automated workflows in a single interface. Block said the product should feel familiar to users who have worked with modern team chat tools.
Agents carry their own identities
Inside Buzz, agents hold their own cryptographic identities and defined permissions. They can post messages, review code, run approved automations, and join conversations alongside human users. Multiple people and multiple agents can share the same workspace and build on each other’s work.
“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.”
Block said 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 that Block first released in January 2025.
Why Block built Buzz on Nostr
Block said it chose Nostr to address what it sees as the most basic issue in multi-agent work: identity. Every participant, human or agent, controls a keypair that belongs to them rather than to the platform. That means an agent’s identity, history, and reputation can move across any Nostr-compatible system.
According to the project repository, each message, reaction, workflow step, review approval, and git event is recorded as a single signed event in one log. The repository also describes a hash-chain audit trail that applies whether the author is a person or a process.
The code has been 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 release is still early: Buzz is shipping as version 0.4.21, with desktop builds for macOS, Windows, and Linux, while mobile clients are not finished yet.
Block frames the product as decentralized, but each workspace runs on a single relay. The project repository describes that relay as the workspace’s “single source of truth.”
Rethinking how teams operate
Block employees have also been discussing how teams should work once software no longer dictates the process. Lucas Isaza, who works on AI and product at Block, wrote in a thread that tools such as Asana, Jira, and Linear had baked sprint structures and Kanban into company rituals, shaping the operating model as much as the work itself.
He said a configurable workspace removes those constraints, which means “the bottleneck becomes the operating model.” In Buzz, he wrote, one thread can hold the diagnosis, the task, the fix, and the surrounding conversation, compressing what once lived across several tools into a single record of why a decision was made.
Isaza said agents can take user-level actions through CLI commands, create their own channels, and update their own memories, while users can set channel-specific or thread-specific rules for each agent. He added that he had experimented with agents that create a shared whiteboard for every thread, producing “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 out of Buzz, Isaza said. He added that most work is collaborative and that “that doesn’t need to stop with AI.”
Block says agents helped build Buzz itself
Thomas Petersen, a principal designer and AI strategist at Block, said the company used agents to build the Buzz platform itself. 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 the interface, which he described as “more sculpted over time than designed up front.”
Part of Dorsey’s broader protocol push
Buzz fits into the open-protocol direction that has defined Dorsey’s work since leaving Twitter. He stepped away from the Bluesky board in 2024 and has since backed a series of tools not controlled by any single company, most of them built on Nostr, the relay-based protocol he has personally funded.
That list includes Bitchat, Dorsey’s Bluetooth mesh messaging app, which China ordered removed from Apple’s App Store in April. The move echoed Beijing’s 2023 ban on Damus, the Nostr-based Twitter alternative. Dorsey has also seeded andOtherStuff, a nonprofit focused on open-source social tools.
Block’s recent AI, payments, and Bitcoin moves
Decrypt noted that Block cut more than 4,000 jobs in February, roughly 40% of its workforce. At the time, Dorsey said AI “fundamentally changes what it means to build and run a company.”
A month later, Dorsey said Cash App would add support for stablecoins to its core payment flow, even as he had been vocal about his reluctance to do so.
In April, Block disclosed in its proof-of-reserves report that it held 28,355 BTC worth $2.2 billion.