Block launched Buzz on July 21 as an open-source workspace with team chat and signed work records for people and agents. Buzz can run Codex and Claude Code; a team assigns work and sees who acted. Buzz signs each agent's events, but approval and offline delivery remain unfinished. Buzz is Slack on AIroids.

1 key
Each human or agent
signs its events
12 msgs
Threads and DMs load
this history by default

Slack where agents are members

Buzz has Slack's channels and DMs, where agents join as members. People can assign work and trace signed events in the same workspace.

SurfaceBuzz featureResult
WorkspaceChannels and DMsCompetes with Slack
AgentsSigned accounts and work historyEach action has an author

Buzz can run Codex and Claude Code as agents while it controls membership and work history.

Each agent gets a key

Buzz gives each person and agent a Nostr key. In its draft owner-agent scheme, an owner signs an attestation for an agent key, and the agent signs its own events. The attestation records provenance; relay membership still controls access. Block states the rule: “authorization does not erase authorship.”

  1. Human identity Human key
    Signs the attestation
    attests to
  2. Agent identity Agent key
    Signs its own work
    produces
  3. Signed activity Work events
    Chat and code activity
    records
  4. Audit trail Work record
    One searchable history
Relay checkShipped behaviorResult
IdentityVerifies event signature and signed-in keyBinds a signed event to one account
Member-only accessClosed workspaces and non-open channels check membershipOrdinary writes honor those rules

Buzz binds each accepted event to the authenticated key and verifies its channel access.

A shared bot account can hide which agent changed a file. Buzz keeps each agent's events separate across chat and Git. If someone steals a key, an admin can remove its relay access without changing the owner's account.

The agent key does not change when its model or harness changes. Buzz should show those changes, or readers may assume the same software still runs it.

The controls are unfinished

ControlCurrent stateGap
Action rightsChannel membership controls accessNo per-action approval
Human approvalWorkflow creates an approval tokenCannot resume after approval

Owner attestation remains a draft Nostr extension that records provenance. Relay membership controls access. Human approval uses a separate workflow step that cannot yet resume a run; Issue #2376 tracks the missing support.

A reported audit failure

Issue #2637 reports that the verifier rejects every audit chain stored in Postgres because Buzz hashes nanosecond timestamps while Postgres stores microseconds. Event signatures show authorship; the audit service cannot yet tell whether stored history changed.

Some work stays outside the event log

Buzz signs chat and Git events. Git objects live in another store, and voice frames never enter the event log. A reviewer can see which key announced a push or approved a change. Teams must check linked objects and later jobs elsewhere.

Models still lose context

Buzz keeps chat and agent work in one record. After a restart, an agent can search it, but the model still gets a limited prompt and a model-written summary. The relay may hold six months of chat; only selected messages enter the prompt.

ControlWhat the code doesLimit
Prompt inputChannel mentions omit history; threads and DMs load 12 messagesLarge messages can still fill the prompt
RecallLoads core memory and offers full-text searchThe agent must fetch notes or choose useful search words

Buzz searches stored events with Postgres full-text search, which matches exact terms and may miss paraphrases. The agent must choose a query and inspect the results.

Buzz loads core memory only when a new ACP session starts. Named memories require a lookup, and a long session may keep an old core record. This lowers prompt use but can leave the agent with stale facts.

ACP prompts carry full event IDs and tags. The native agent resends saved history and tool schemas during tool calls. Its handoff replaces old history with a model-written summary; after ten handoffs, Buzz drops older turns.

Stored history helps only when an agent loads it.

When Buzz runs Codex or Claude Code through ACP, each runtime controls its own context and compaction. Buzz can track reported token use and add room history. The repository has no benchmark that compares token use with and without Buzz.

One cost report

Issue #2631 says four configured agents spawned about 220 Codex processes and used 17.7 million tracked tokens. The reporter says Buzz pre-started too many agent processes. A bad pool setup can raise both process count and token use.

Live ACP sessions restart crashed agents

The ACP layer sends one prompt at a time per channel and batches later events. If an agent process crashes, Buzz starts a new one. These controls do not replay work missed while the agent was offline.

Agents can miss stored messages

ACP replays events from about five seconds before startup, and its default mentions mode accepts only tagged events. Issue #1743 reports missed offline mentions; issue #2270 reports missed untagged thread replies.

Git review happens in chat

Buzz runs a Git server. Its Projects preview shows pull requests and review decisions. Teams can host Git without GitHub, while runners and security tools remain outside Buzz.

Private channels leave repositories readable

Issue #2469 says every signed-in member of a Buzz community can read each hosted repository, including projects tied to private channels. Channel roles limit pushes while reads remain open. PR #2539 adds private repository reads and remains unmerged.


One relay runs each community

Block calls Buzz decentralized because it uses Nostr keys and signed events. One relay holds each community's record; clients and relays do not copy events elsewhere. A team can run its own relay and reuse its keys on another server. Each community still depends on one operator for service and access.

Who can read hosted Buzz

Hosted messages and DMs lack end-to-end encryption. Block may read them or send them to outside model providers; by default, it keeps messages and media for up to 180 days.

A self-hosted team controls its relay. Remote model providers may still receive prompts. The team must also run four data stores and own upgrades and recovery.

Try one project room

TrialUse it whenRisk
HostedTwo agents handle non-sensitive workBlock and model providers may read the work
Self-hostedThe team can run the relay and data storesModel providers may still see prompts

Wait when work needs working approval and offline delivery, or when code must stay private.

Run the same tasks in Buzz and one direct agent runtime. Hold the inputs and pass condition fixed, including the model and token limit. Count extra messages and rework. Stop if Buzz adds cost without cutting coordination work.

Low-risk work is the current limit

signal Approval and delivery pass restart tests

Pause a code-writing run for human approval, restart the relay service, then approve it. The run should resume once. Next, mention an offline agent and restart it; the saved work should arrive once. Both tests must pass before teams trust approval-gated delegation.

signal Private project code follows room access

A private-channel member should clone its repository. A signed-in non-member should get the same response as a missing repository.

Buzz's strongest idea is the agent account: a key and work record that survive the model session. Keep merge rights and secrets outside Buzz until the approval restart, offline delivery, and private-repository tests pass.

Research state I audited block/buzz main at cfdea818 on July 24, 2026, after the July 21 launch. Issues #1743, #2270, #2376, #2469, #2631, and #2637 were open; PR #2539 was open and unmerged. Issue #2631 covers Desktop v0.4.23. I treat issue behavior as reported unless cited code confirms it.
Sources & Evidence
Block launched Buzz on July 21 with an Apache-2.0 license and self-hosting support Teams can inspect the code and run their own server.
Block launch
Buzz provides Slack-like workspace tools and connects to separate agent runtimes Teams can change the runtime without replacing the workspace.
Buzz vision
Agents have their own keys and revocable relay access An agent keeps its authorship when an owner attests to its key.
Block Engineering
Owner attestation remains an optional draft Nostr extension Relay access and action approval remain separate.
NIP-OA draft
The relay verifies each signed event and matches its key to the signed-in key An accepted event belongs to one authenticated account.
Relay ingest
Closed Buzz workspaces check membership during NIP-42 authentication Workspace membership remains a separate access check.
Relay authentication
Ordinary writes to non-open channels pass a membership check Private channel writes require membership.
Relay access checks
The workflow engine fails runs that reach request_approval Buzz cannot yet resume work after a person approves it.
Workflow engine
Open issue #2376 tracks work to pause and resume runs for approval The missing approval path remains open at the research cutoff.
Buzz issue #2376
Open issue #2637 reports audit verification failures after timestamps lose precision The audit service cannot yet distinguish clean history from changed history.
Buzz issue #2637
Large objects live outside the event log, and voice frames are ephemeral Signed events identify the work; other stores hold its contents.
Buzz architecture
Buzz loads 12 messages for threads and DMs; agents must request ordinary channel history The fixed limit uses fewer prompt tokens but leaves recall to the agent.
ACP context configuration
ACP prompt blocks retain full event metadata and tags Those fields add tokens to each prompt.
ACP prompt formatting
The native agent summarizes near its context limit, then drops old turns after repeated handoffs The agent can lose facts during long tasks even when the room keeps them.
Native context handoff
Buzz loads core memory at session start; agents must fetch named memories Long sessions can use old core memory, while named notes need a lookup.
Agent memory specification
History retrieval uses filtered Postgres full-text search Recall depends on useful search words.
Search query implementation
Git clone, fetch, and push ship through standard Smart HTTP Teams can host code on Buzz itself.
Git transport
The Projects preview builds pull-request views and review decisions from signed events Review work can happen inside Buzz.
Projects pull-request code
One relay holds each community record; Buzz has no peer or relay replication One operator controls service and access for each community.
Buzz architecture
Open issue #2631 links about 220 Codex processes and 17.7 million tracked tokens to pre-started agents Bad pool settings can raise token use; the issue does not measure normal use.
Buzz issue #2631
ACP sends one prompt per channel and restarts crashed agent processes Crash recovery can still miss older work.
ACP architecture
Open issue #1743 reports that an offline agent can miss a stored mention The agent cannot act on a message it never receives.
Buzz issue #1743
Open issue #2270 reports ignored thread replies unless the agent gets a fresh tag A person may need to tag the same agent on every turn.
Buzz issue #2270
ACP first subscribes from about five seconds before process startup Older offline mentions may remain unprocessed.
ACP startup watermark
Default ACP mention mode adds a tag filter to the relay subscription An untagged thread reply does not reach the agent.
ACP relay filter
Open issue #2469 says every authenticated community member can read each hosted repository A private project channel can expose its code to the whole community.
Buzz issue #2469
Open PR #2539 adds channel-scoped private repository reads but remains unmerged Private channel code still lacks shipped read controls.
Buzz PR #2539
Hosted messages and DMs lack end-to-end encryption, and Block may access them The relay operator may read sensitive work.
Buzz support
Block may send channel content to model providers and keep messages or media for up to 180 days Outside model providers may receive workspace content.
Buzz privacy notice
The production stack requires four persistent data volumes The team owns every backup and restore.
Deployment guide