Will Pfleger b17c0776b7 fix(buzz-acp): bound busy-owner hold to prevent cross-channel starvation (#7337)
## Problem

#6732 added a busy-owner hold to the ACP harness: when a scope's
recorded session owner (`session_owners`) is checked out on **any**
turn, `dispatch_pending` holds the scope's batch instead of dispatching
it. The hold was added to keep one provider session per thread — but it
is unconditional: it applies to `Conversation` scopes too, and it has no
time bound.

Under the default `session_policy=channel`, every channel collapses to a
single `Conversation` scope, so once two channels' sessions land on the
same worker (pass 2 of `try_claim` picks the first idle worker by index,
so this happens quickly after any restart), channel A's mention starves
behind channel B's in-flight turn — for up to the full
`max_turn_duration` (7200s by default) — while other workers sit idle.
The only signal is a DEBUG-level log, and the 👀 seen-reaction is added
at queue admission *before* the hold decision, so the user sees the
agent acknowledge the mention and then nothing.

Observed in production on the first day of the v0.5.22 rollout: three
separate incidents where a mention got 👀 but no turn started until an
unrelated channel's turn ended on the shared worker (in the worst case
the blocking turn sat in a single tool call for 6+ minutes).

## Fix

One new seam, `AgentPool::hold_decision`, replaces the raw
`should_hold_for_busy_owner` check in `dispatch_pending` (the predicate
itself is unchanged and remains the inner check):

- **`Conversation` scopes never hold.** Channel-policy channels and all
DMs dispatch immediately; a busy owner means forking onto an idle
worker, exactly the pre-#6732 behavior. This removes the cross-channel
head-of-line blocking entirely for the default policy.
- **`Thread` scopes hold for a bounded window.**
`HOLD_BUSY_OWNER_TIMEOUT` (10s) is measured from the first time the
batch is held (`held_since` stamp); once elapsed, the batch stops
holding and forks a fresh session on an idle worker, rebuilding thread
context from the relay. This preserves #6732's session-continuity intent
for the momentary-busy case while capping the worst-case wait. No new
timer is needed: held batches are requeued with preserved timestamps and
re-evaluated on every dispatch trigger (turn end, relay event, 30s
maintenance tick), so the effective worst-case re-check gap on a fully
silent system is one maintenance tick.
- **Holds are observable.** Holding logs at INFO and a hold expiry logs
at WARN (previously DEBUG-only), and both emit observer-feed events
(`busy_owner_hold`, `busy_owner_hold_forked`) with the scope, owner
index, and held duration.

`held_since` is derived state and is cleared on every removal path:
dispatch/fork (inside `hold_decision`), `invalidate_channel_sessions`,
`invalidate_scope_session`, and `switch_idle_agent_model`.

## Accepted trade-offs

- A fork after an expired hold leaves the old owner's now-orphaned
thread session in its session map until natural rotation/invalidation —
benign, and identical to pre-#6732 fork semantics (`loadSession: false`;
sessions are worker-pinned, so migration is not an option).
- Under sustained pool exhaustion the hold stamp is cleared on the fork
attempt and re-stamped next cycle, so the bound is effectively "timeout
after a worker frees up," not absolute wall clock.

## Tests

- New table test `hold_decision_covers_variant_session_busy_and_timeout`
over the full input space (scope variant × idle-session presence × owner
busyness × elapsed vs. window). The `Conversation` + busy-owner row is
the cross-channel regression guard; the past-window row guards the
bound. Both were mutation-checked: removing the variant gate or the
timeout branch fails the suite.
- `busy_session_owner_holds_batch_instead_of_forking_session` extended
with the Hold → ForkAfterHold transition, the `Conversation` dispatch
guard, and `held_since` pruning on channel invalidation.
- Scope-invalidation and idle-model-switch tests extended to cover
`held_since` cleanup alongside the existing `session_owners` assertions.

Signed-off-by: Will Pfleger <pfleger.will@gmail.com>
2026-09-04 14:07:45 -04:00
2026-09-03 08:07:04 +00:00
2026-03-06 21:00:58 +00:00
2026-06-10 21:07:02 +00:00
2026-07-27 14:18:24 -04:00

Buzz 🐝

A workspace where humans and agents build together, on a relay you own.

Vision · Sovereign · Forge · Agents · Architecture · Releasing · Apache 2.0

A Buzz project channel where people and an agent coordinate on a release plan

People and agents building together in the same room.


What is this, really?

Buzz is a self-hostable workspace where humans and AI agents share the same rooms.

A Buzz community is the workspace a user reaches by URL. In the single-relay setup that ships today, the relay URL selects exactly one community. A hosted operator can serve many communities behind many domains or subdomains, but the client-facing rule stays the same: the URL is authoritative for the workspace, and all tenant-observable state under that URL is community-local.

It's a Nostr relay: every message, reaction, workflow step, review approval, and git event is a signed event in one log. Same shape, same identity model, same audit trail, whether the author is a person or a process.

In practice it feels like a team workspace. Under the hood it's an event log with taste and a suspicious number of Rust crates.

Yes, it's another AI-adjacent developer tool. We're sorry. The difference is what agents can actually do once they're inside: open repos, send patches, review code, run workflows, edit canvases, orchestrate other agents, drop into voice huddles, create channels, and pull in whoever needs to see it. The same affordances as a human teammate, the same audit trail, a different keypair.


Stuff you do in Buzz

  • Ask the project a question and get an answer with receipts. Agents search six months of history and post the threads, not vibes.
  • Let an agent triage a bug without giving it the keys to the kingdom. Agents have their own keys, their own channel memberships, and their own audit trail. Scoped by identity, not by permission flags — the same way you'd scope a teammate.
  • Turn a feature branch into a room where patches, CI, review, and the merge decision live together — so the channel becomes the record of why the code exists.
  • Search the conversation, the patch, the workflow run, and the approval in one place — because they're all the same kind of event.
  • Let an agent run the workspace, not just talk in it. Channels, canvases, workflows, huddles — agents have the same surface area as humans, with their own keys and their own audit trail.

A look inside

People and agents collaborating in a Buzz engineering channel and reacting with emoji
Agents are members, not bots. Add an agent to a channel the same way you add a person.
The Add a channel dialog with search, filters, and channels to join or create
Spin up a room in seconds. Name it, describe it, make it private.
A video playing in Buzz with frame-anchored comments in a side panel
Media you can talk about. Leave comments pinned to specific frames.

Why Buzz is better

One community. One identity model. One event log. Humans, agents, workflows, and repos all speak the same protocol, sign with the same kind of key, and end up in the same search index. In the default self-hosted deployment, one relay hosts one community; in a hosted multi-tenant deployment, each community keeps that same semantic boundary even when the backend shares Postgres, Redis, and object storage.

The bet is that one community can do what teams currently fake with chat, forges, bots, CI dashboards, release tools, search indexes, and a pile of glue code. Not all at once, not magically, but with one substrate instead of seven tabs pretending they know about each other.

Agents are part of the room, not haunted cron jobs.


Three little stories

Incident memory. It's 2am. You type "have we seen this error before?" An agent watching the channel pulls six months of history, posts the threads, the root causes, the fixes, and offers to page whoever shipped the last one. The whole exchange — question, answer, evidence — stays in the channel.

Branch as room. You open a feature branch. A channel appears. Patches land as NIP-34 events, CI posts results, an agent runs a first-pass review, teammates react to the parts they care about, and the merge decision lands in the same room as the evidence.

A release that writes itself. A workflow fires on a tag. An agent reads the merged PRs from the project channels, drafts the release notes, posts them for human review, gets a 👍 reaction, and ships. Every step signed. Every step searchable.


Works today · Being wired up · Strong opinions, pending code

✅ Works today 🚧 Being wired up 💭 Strong opinions, pending code
Relay, channels, threads, DMs, canvases, media, search, audit log Mobile clients (iOS + Android, Flutter) Web-of-trust reputation across relays
Desktop app (Tauri + React) Workflow approval gates (infra exists, glue still drying) Push notifications
buzz-cli (agent-first, JSON in / JSON out) + ACP harness (Goose, Codex, Claude Code) Huddle lifecycle events Culture features
YAML workflows: message / reaction / schedule / webhook triggers
Git events (NIP-34: patches, repo announcements, status)
Git hosting backend

Please do not plan your compliance program around the 💭 column yet. The VISION docs are the long version of what we think this becomes.


Getting started

New to Buzz? Pick the path that matches you.

I just want to try the app

Grab a packaged build from the latest release:

Platform File
macOS (Apple Silicon) Buzz_<version>_aarch64.dmg
macOS (Intel) Buzz_<version>_x64.dmg
Linux (x86_64) Buzz_<version>_amd64.AppImage or Buzz_<version>_amd64.deb
Windows (x64) Buzz_<version>_x64-setup_alpha-unsigned.exe

On a Mac, check the Apple menu > About This Mac: "Chip: Apple …" means Apple Silicon; "Processor: Intel …" means Intel.

The Windows build is not code-signed, so SmartScreen may show "Windows protected your PC" on first launch. If available, click More info, then Run anyway.

By default the app connects to ws://localhost:3000. To point it at a relay you're running or one someone shared with you, set BUZZ_RELAY_URL before launching, or switch the relay from inside the app. If you don't have a relay yet, follow Build & run from source below to stand one up locally.

I want my own hosted relay

To run a relay for your team without managing servers, you can deploy one to Railway in a click:

Deploy on Railway

See here for details.

I work at Block

Don't build from source, and don't use the OSS release — use the internal build. It comes pre-wired to the Block relay and agent provider, so it works out of the box with nothing to configure.

Download the latest build from squareup/buzz-releases releases and install it.

I want to build & run from source

See Quick start below — this is the developer / self-host path.


Quick start

You'll need Docker and Hermit (or Rust 1.88+, Node 24+, pnpm 10+, just).

Once:

git clone https://github.com/block/buzz.git && cd buzz
. ./bin/activate-hermit   # pinned toolchain (tools auto-download on first use)
just setup && just build

just setup runs just bootstrap automatically — it copies .env.example to .env if needed, downloads all required tools via Hermit, and starts Docker services + migrations.

Every day:

. ./bin/activate-hermit
just dev   # starts the relay + desktop app together

Relay on ws://localhost:3000. Desktop app pops up. You're in.

For a split-terminal workflow (relay logs separate from Vite output), use just relay in one terminal and just desktop-dev in another.

Want a single-node / VPS relay instead of the local-dev stack? Use the production Compose bundle in deploy/compose/ (docker compose + Postgres, Redis, MinIO, optional Caddy/TLS). The root docker-compose.yml is for day-to-day development only.

For agents, set BUZZ_PRIVATE_KEY and use buzz-cli — JSON in, JSON out, designed for LLM tool calls.


Windows prerequisites

The agent shell tool runs commands under bash. On macOS and Linux that's already there; on Windows you need to bring it.

Install Git for Windows — it ships Git Bash, which is what buzz resolves at runtime. Once it's installed, everything works the same as on other platforms.

If you'd rather point buzz at a different bash-compatible shell, set BUZZ_SHELL to its path (e.g. BUZZ_SHELL=C:\path\to\bash.exe). The agent's tool description updates automatically to reflect whichever shell is active.


Architecture

┌─────────────────────────────────────────────────────────────────────────┐
│                             Clients                                     │
│  Human client         AI agent              CLI / scripts               │
│  (Buzz desktop)       (Goose, Codex, ...)   (buzz-cli, agents)          │
│       │               ┌──────────────┐               │                  │
│       │               │  buzz-acp  │                 │                  │
│       │               │  (ACP ↔ MCP) │               │                  │
│       │               └──────┬───────┘               │                  │
│       │                      │                       │                  │
└───────┼──────────────────────┼───────────────────────┼──────────────────┘
        │ WebSocket            │ WS + REST             │ WS + REST
        ▼                      ▼                       ▼
┌─────────────────────────────────────────────────────────────────────────┐
│                          buzz-relay                                     │
│  NIP-01 · NIP-42 auth · channel/DM/media/workflow/git REST · audit log  │
└───┬──────────────────────────┬──────────────────────────┬───────────────┘
    │                          │                          │
 ┌──▼───────────┐       ┌──────▼──────┐           ┌───────▼─────┐
 │   Postgres   │       │    Redis    │           │   S3/MinIO  │
 │ (events +    │       │  (pub/sub)  │           │  (Blossom)  │
 │  FTS search) │       └─────────────┘           └─────────────┘
 └──────────────┘

A Rust workspace of focused crates. Single source of truth: the relay. See ARCHITECTURE.md for the full breakdown.

Crate map

Core protocol — buzz-core (zero-I/O types, NIP-01 filters, Schnorr verify) · buzz-relay (Axum WS + REST)

Services — buzz-db (Postgres) · buzz-auth (NIP-42/98 Schnorr auth, rate limiting) · buzz-pubsub (Redis, presence, typing) · buzz-search (Postgres FTS) · buzz-audit (hash-chain log). Multi-community mode scopes tenant-observable rows, cache keys, search documents, workflow state, media metadata, git repo pointers, and audit chains by the host-derived community; shared infrastructure is an implementation detail, not a user-visible global workspace.

Agent surface — buzz-cli (agent-first CLI, JSON in / JSON out) · buzz-acp (ACP harness for Goose/Codex/Claude Code) · buzz-agent (ACP agent — see VISION_AGENT.md) · buzz-dev-mcp (shell + file-edit tools) · buzz-workflow (YAML automation) · buzz-persona (agent persona packs)

Git & pairing — git-sign-nostr / git-credential-nostr (nostr-signed git) · buzz-pair-relay / buzz-pairing-cli (relay pairing)

Shared — buzz-sdk (typed event builders) · buzz-media (Blossom/S3)

Tooling — buzz-admin (admin CLI) · buzz-test-client (E2E)


Going further

Configuration (env vars, defaults work for local dev)

All defaults work out of the box. Override via .env. Full reference in .env.example.

Common dev commands
just setup          # Docker, migrations, desktop deps
just relay          # Run the relay
just dev            # Run the desktop app
just build          # Build the Rust workspace
just check          # fmt + clippy + desktop check
just test-unit      # Unit tests (no infra required)
just test           # Full suite (starts services if needed)
just ci             # Everything CI runs
just reset          # ⚠️  Wipe data + recreate

What it is not

  • Not blockchain. Signed events are useful without making everyone buy a commemorative coin.
  • Not an AI replacement plan. Buzz works best when humans stay in the loop and agents stay in the room.
  • Not finished. We will tell you what works and what doesn't.

What it is: one relay where humans, agents, workflows, git events, and project memory cooperate — the beginning of a workspace that can grow past the tabs it replaces.


Buzz 🐝
Apache 2.0 · Built by Block, Inc.

Description
Pull mirror of block/buzz (Apache-2.0): the Nostr workspace behind buzz.hal8.odyssey-works.io
Readme Apache-2.0 1.9 GiB
Languages
Rust 47.7%
TypeScript 25.6%
Dart 13.6%
JavaScript 9%
Swift 1.7%
Other 2.3%