00ecf2cac7
## Summary
NIP-29 `kind:9000` (PUT_USER) role changes were only authorized when the
**new** role was elevated. Demotions were unauthorized, so any
authenticated user could strip a channel owner to `member` with a single
event — and the demotion was unrecoverable, since the ex-owner then
lacked the privilege to restore themselves.
Reported by @Tyler in `#buzz-security`. Verified true, plus two adjacent
defects the report flagged and one it did not.
## The defects
1. **Demotion unauthorized.** The actor check only fired when the
*requested* role was elevated. Lowering someone's role skipped it
entirely.
2. **Open channels skipped the actor check.** It was nested under
`visibility == "private"`.
3. **`add_member` had no last-owner guard** while `remove_member` did —
so a channel could be left with zero owners.
4. **(Not in the report.)** An absent `role` tag defaulted to `Member`,
so a bare self-targeted PUT_USER silently demoted the sender. No
attacker required.
## The fix
**`crates/buzz-db/src/channel.rs`** — the authority, because it also
covers the desktop/admin callers that bypass the relay validator:
- Changing an **active** member's role requires an elevated actor **in
both directions**. Re-adding at the same role stays unguarded and
idempotent (the huddle bot-add and `kind:9021` join paths depend on
this).
- Last-owner guard in `add_member`, mirroring `remove_member`.
- Keyed on the **active** role (`removed_at IS NULL`). A soft-removed
row's role is history, not live authority — otherwise soft-deleted
ownership becomes a resurrection token: a kicked owner self-rejoins via
`9021` and silently regains ownership.
- New `pg_advisory_xact_lock` on a channel-membership namespace, taken
as the first statement in both `add_member` and `remove_member`. Both
read an owner `COUNT` and then write a *different* row, so READ
COMMITTED alone lets two concurrent demotions each observe 2 owners and
together leave 0.
- `remove_member`'s `is_agent_owner` lookup moved before the transaction
opens — it borrows a second pool connection, and issuing it while
holding the lock could self-deadlock on a small pool. Safe because
`agent_owner_pubkey` is immutable (first-mint-wins).
**`crates/buzz-relay/src/handlers/side_effects.rs`**:
- Role tag is now `Option` — absent means "no role change requested"
rather than defaulting to `Member`.
- Actor-role lookup hoisted out of the `visibility == "private"` block,
so open channels are covered.
- Role-change and last-owner guards on every visibility. Rejecting here
*as well as* in the DB means clients get a real error instead of an `OK`
whose side effect then fails silently.
## Verification
**Mutation tested — every guard stubbed individually to confirm a test
actually dies.** Three of eight guards were originally uncovered and
survived being disabled with the suite fully green:
| Guard | Dying test |
|---|---|
| DB actor-auth | *survived* → **new**
`unprivileged_member_cannot_demote_a_co_owner` |
| DB last-owner | `owner_can_still_manage_roles_after_demotion_guard` |
| DB active-role (soft-remove) |
`kicked_owner_rejoins_as_member_not_owner` + 3 |
| `add_member` advisory lock |
`membership_writes_serialize_on_the_shared_channel_lock` |
| `remove_member` advisory lock | +
`remove_member_rejects_an_actor_demoted_while_it_waited` |
| relay no-role-tag preservation |
`test_nip29_put_user_without_role_tag_preserves_role` |
| relay actor-auth | *survived* → **new**
`test_nip29_relay_rejects_role_change_by_unprivileged_actor` |
| relay last-owner | *survived* → **new**
`test_nip29_relay_rejects_last_owner_self_demotion` |
The three gaps shared one cause: every existing test asserts resulting
**state** ("the role did not change"), and the DB guards enforce that
state, masking every layer above them. With a relay guard stubbed the
relay answers `accepted:true` and logs `Side effect failed: access
denied: ...` while the state assertion still passes — the entire relay
validator could be deleted unnoticed. The new relay tests assert
`accepted == false` instead, the one observable only the validator
controls. Each new test is verified in both directions: green against
the real fix, failing with its intended message when its guard alone is
stubbed.
**Test runs** (at `9461eedb`):
- `buzz-db`, serial: **210 passed / 3 failed** — the same 3 failures as
clean `main` (202/3), which are pre-existing and unrelated
(`concurrent_same_owner_create…`,
`create_community_with_owner_is_atomic…`,
`test_usage_metrics_lock_has_single_owner…`). +8 = the new tests.
- `e2e_relay --ignored`: **40 passed / 3 failed**. Clean `main` on the
same relay is 35/6 — the same 3 infra failures
(`test_invite_mint_and_claim…`, `test_subscription_limit_enforced`,
`test_unarchive_emits_member_added_notification`) plus the 3 security
tests that fail unpatched and pass here.
- `cargo fmt`, `clippy`, `git diff --check` all clean.
**Live manual drive** against a locally running relay, using raw
`nak`-signed events (the `buzz` CLI refuses malformed `kind:9000`, so
the guards have to be exercised directly):
- *Rejected:* member demotes owner; member demotes admin; self-promote
to owner; self-promote to admin; admin demotes the last owner; sole
owner self-demote; demoted ex-owner demotes last owner; private-channel
member demotes owner; non-member demotes owner in private.
- *Allowed:* bare PUT_USER with no role tag (owner keeps role);
idempotent re-add at same role; owner promotes admin→owner, then owner2
legitimately demotes owner1.
- *Resurrection defeated:* owner promotes attacker to admin → kicks them
(`9001`) → attacker self-rejoins (`9021`) → returns as **member**, not
admin, and cannot demote the owner.
- Normal ops unaffected throughout: channel creation, messaging, member
listing, and legitimate governance all work.
## Behavior change to be aware of
Huddle bot-add sends `role="bot"`. If the target is **already an active
member at a different role**, that is now a role change and requires an
elevated actor. Previously it silently re-roled them — the same privesc
primitive through a different door, so narrowing it is intended.
This does not break the huddle flow in the path that matters: the
ephemeral channel add (the one that fails hard) is performed by the
host, who *created* that channel and is therefore its owner — verified
live. The parent-channel add is already explicitly best-effort,
capturing the error into `parent_error` with a comment anticipating "may
already be member"; adding a non-member agent there still works.
Flagging it rather than burying it.
## Notes
- Commit is **signoff-only, not cryptographically signed** — `-S` fails
in this environment (git tries to load the agent npub as an SSH key
file). DCO trailers are present and correct.
- Branch was merged with `origin/main` via `--no-ff` (not rebased).
Upstream had 17 commits, none touching these files, no migration
changes.
---------
Signed-off-by: tlongwell-block <109685178+tlongwell-block@users.noreply.github.com>
Co-authored-by: Dawn (sprout agent) <c6237ef84fa537c78dcee78efd2d4e59f728859c7f194da42ac51ededfa0be05@sprout-oss.stage.blox.sqprod.co>
Buzz 🐝
A workspace where humans and agents build together, on a relay you own.
Vision · Sovereign · Forge · Agents · Architecture · Apache 2.0
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
 Agents are members, not bots. Add an agent to a channel the same way you add a person. |
 Spin up a room in seconds. Name it, describe it, make it private. |
 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 — macOS (.dmg), Linux (.AppImage / .deb), or Windows (.exe). Install it like any other app.
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 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
- VISION.md · VISION_SOVEREIGN.md · VISION_PROJECTS.md · VISION_AGENT.md — the four vision docs
- ARCHITECTURE.md — system design, kind ranges, subsystem boundaries
- TESTING.md — multi-agent E2E test suite
- CONTRIBUTING.md · CODE_OF_CONDUCT.md · SECURITY.md · GOVERNANCE.md
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.