Files
buzz/docs/nips
Bradley Axen a3a47e6294 feat(relay): add an unlisted channel setting (#8579)
🤖

## Summary

Sharing a Solo chat with a large channel today means adding every person
as a member, one at a time, and the app blocks the share past 100
people. The plan is to share it the way Google Docs does with "anyone at
the company with the link". Buzz's `open` visibility already gives that
kind of access: anyone in the community can read and join an open
channel. The problem is that an open channel also shows up in everyone's
channel list and search, and a private chat shouldn't appear there just
because its link was posted somewhere.

This PR adds a channel setting, `unlisted`. An **unlisted open channel**
can be read and joined by anyone who names it by id (from a shared
link). For non-members, it is left out of every read that does not name
it. Members see it as before. This is the relay side only; the buzz-app
change comes later. #8575 (batch adds) remains the path for small
audiences.

Unlisted is not an access control. Anyone who has the id can read the
channel, and that is intended.

## Solo flows this supports

Each user action is one event. The buzz-app side comes later; the relay
supports all of these now.

| Flow | Event | Result |
| --- | --- | --- |
| New Solo chat | kind:9007 `visibility private` + `["unlisted",
"true"]` | The chat starts unlisted, so it stays unlisted when any
client later opens it. |
| Share | One kind:9002: `visibility open` + `unlisted true` +
`join_role guest\|member`. Then post the link. | Anyone with the link
can read the chat by id, both history and live. Nobody is added as a
member, so the chat isn't in anyone's channel list. A non-member can't
post; `join_role` decides whether someone who joins can. |
| View | A REQ that names the chat by `#h`, or by `#d` for its metadata
| A non-member can read it. It is never listed for them. |
| Reply | kind:9021 join (the app sends it before a viewer's first
reply) | Joining makes them a member with the role from `join_role`, so
with `member` they can post. A kind:9022 leave makes them a viewer
again; the chat stays readable by id. |
| Unshare | kind:9002 `visibility private` | The existing open→private
eviction closes non-members' live subscriptions. New reads by
non-members are refused. |
| Convert to a channel | One kind:9002: `["t", ""]` + `unlisted false`,
plus `visibility` | Clears the Solo label. Non-members can now find it
in discovery. |

**Sidebar pins are not relay state.** Pin and unpin live in the app's
existing kind:30078 sidebar preferences, which sync across devices and
don't touch membership. Don't map them to join/leave: someone a chat was
shared with by member add is already a member, so a leave would remove
their access.

Your own Solo chats keep showing up, because you're their owner member,
and members see unlisted channels everywhere. Existing Solo chats aren't
backfilled. They get the flag when they're shared, because the share
event sets it.

**Open question, not built here:** someone who only views a shared chat
isn't a member. A mention of them doesn't reach their inbox (`#p:[me]`
without `#h`) and sends them no push.

## Behavior

| Reader | Reads that don't name the channel (kind:39000 without `#d`,
`#P` creator queries, messages, COUNT, NIP-50 search, artifact queries,
channel list) | Reads that name it (`#h`, or `#d` on 39000–39003) |
kind:9021 join |
| --- | --- | --- | --- |
| Member | Listed | Readable | n/a |
| Non-member, unlisted open channel | **Not listed** | Readable | Works;
`join_role` still decides the role |
| Non-member, private channel (unlisted or not) | Not listed | Not
readable | Refused |

- **Setting it:** kind:9002 `["unlisted", "true"]` / `["unlisted",
"false"]`. Owner or admin only, like `visibility`. A missing tag means
no change. It can be sent in the same event as `["visibility", "open"]`,
so a private chat becomes open and unlisted in one step. Any other value
is refused before the event is stored. The relay posts an
`unlisted_changed` system message and clears the accessible-channels
cache across nodes. Nobody loses access when a channel is unlisted, so
no subscriptions are evicted.
- **At creation:** kind:9007 also takes `["unlisted", "true"|"false"]`.
A missing tag means listed. Any other value is refused before the event
is stored, as on kind:9002. It is stored with the channel row in the
create's transaction, on both the client-UUID path and the
relay-chosen-UUID path.
- **kind:39000** carries a bare `["unlisted"]` flag while the setting is
on. It does not add NIP-29 `hidden`, so the metadata stays readable by
id.
- **NIP-11** advertises `buzz-unlisted-channels` in
`supported_extensions`. A relay without this PR would apply
`["visibility", "open"]` and ignore `unlisted`, which would list the
chat publicly. So buzz-app must check for the extension before it sends
that pair.
- **CLI:** `buzz channels update --channel <id> --unlisted true|false`
and `buzz channels create ... --unlisted`.
`buzz_sdk::build_update_channel` takes a new `unlisted: Option<bool>`
argument, and `buzz_sdk::build_create_channel` takes `unlisted: bool`,
which emits the tag only when true.

### Open question: does `unlisted` only mean something when the channel
is open?

**Decision: store it on its own; it only has an effect while the channel
is open.** Private channels are already invisible to non-members, so on
a private channel the flag does nothing. It is still stored and
published, for three reasons:
- a client can mark a Solo chat unlisted before opening it, or in the
same event that opens it, so the chat is never listed even for a moment;
- switching private → open → private → open keeps the setting;
- there is no cross-field rule in kind:9002 to validate or keep in sync.

kind:39000 publishes the flag as stored, whatever the visibility, so
clients can show the setting.

## How

The relay already has a "readable only when named" path for system
channels (NIP-CL). Unlisted open channels reuse it:

- **`get_accessible_channel_ids`**: the open half (the implicit scope of
a REQ that doesn't name a channel) adds `AND NOT unlisted`. The member
half is unchanged, so members still have the channel.
- **`get_readable_named_only_channels`**: also returns unlisted open
channels of the legacy types. Every reader of that set (REQ, COUNT,
NIP-50 search, HTTP `/query` and `/count`, thread windows, workflow run
reads) adds a named-only channel only to a filter that names it, through
`filter_channel_scope`. An unlisted channel's type is `stream`/`forum`,
so the `#t:["system"]`/`#P` system opt-in never adds it.
- **`get_accessible_channels`** (the channel list): open channels are
listed to non-members only when not unlisted.
- **`query_artifacts`**: an artifact in an unlisted open channel reaches
a non-member only when the query's `#h` names that channel.
- **Live fan-out:** no change was needed. A global subscription never
receives channel-scoped events, kind:39000 included (`fan_out_scoped`).
A channel-scoped subscription has to name the channel, and that goes
through the same named-only authorization.

**Left alone on purpose:** access checks that read a named channel or
event keep treating an unlisted channel as open. These are
`handle_join_request` (kind:9021), the ingest write gate,
operator-listener mention delivery (`load_deliverable_event`), personal
read-state writes, and push matching. Push matching still requires
membership, so non-members get no pushes from an unlisted channel.

**Named reads checked:** these callers use the implicit channel set
(`get_accessible_channel_ids`, its cache, `get_accessible_channels`).
Every one that reads a channel the request names also adds the
named-only set, so a non-member can still read an unlisted open chat by
id. That covers WS REQ (history, live registration, NIP-50 search), WS
COUNT, HTTP `/query` and `/count`, thread windows and workflow run
reads. Other named reads don't use the implicit set: they check
visibility or membership, so an unlisted open chat counts as open. Those
are live fan-out, the ingest write gate, typing, kind:9021 join, huddle
audio join, operator-listener delivery, the workflow sink and read-state
writes. Feed queries (mentions, needs-action, activity) and the
`/buzz/v1/me/sidebar` accessory API are lists, so leaving out chats you
only view is intended. Media reads don't check channels. `buzz-auth`'s
`ChannelAccessChecker` has no production implementation.

## Database (docs/database.md checklist)

- **Phase:** expand only. The migration adds a column with a constant
default, and the same release ships the code that reads and writes it.
No backfill or contract step follows.
- No trigger, function, procedure, rule or foreign key is added.
- No migration changes existing rows. `ADD COLUMN ... BOOLEAN NOT NULL
DEFAULT FALSE` stores the constant default in the catalog, so the table
is not rewritten.
- Every location in Rule 4 is updated:
`migrations/0069_channel_unlisted.sql`,
`schema/tables/public/channels.sql`, and the migration count. No seeds,
types or reconcile changes are needed.
`admin_schema_parity_between_desired_state_and_migrations` now compares
`channels` columns between the pgschema desired state and the migrated
database. I failed it once by removing the column from `channels.sql`.
Only columns are compared for `channels`: on current `main`, pgschema
already re-emits `idx_channels_id_live` without its `INCLUDE
(community_id)`, an index drift that predates this PR and is noted in
the test.
- **Currently deployed relay against the new schema:** it never selects
or writes `unlisted`, and every insert gets the default. All
channel-record queries name their columns. Nobody can set the flag until
this relay ships, because the old relay refuses a kind:9002 whose only
tag is `unlisted`.
- The migration starts with `SET LOCAL lock_timeout = '5s'`. No index is
added: the new predicates ride the existing `(community_id, visibility)`
index.

## Rollout

1. Deploy. Every channel stays listed, so nothing changes.
2. **Don't unlist any channel while an old relay is still running.** An
old relay ignores the column and lists the channel to everyone. The
NIP-11 extension lets clients gate on this. Unlisted isn't an access
boundary, so a mixed fleet only exposes the channel in listings for a
while.
3. **Rollback:** an older relay ignores the column, so unlisted channels
show up as ordinary open channels again. Nothing breaks.

## Tests

Postgres (`buzz-db`, discovered by the Postgres lane):
- `unlisted_open_channel_is_named_only_for_non_members`: sets the flag
through `update_channel`. Then checks that a non-member doesn't get it
from `get_accessible_channel_ids` or `get_accessible_channels`, and does
get it from `get_readable_named_only_channels`; that a member still
lists it; that `put_member` (the kind:9021 path) lets the non-member
join, after which they list it; and that listing it again shows it to a
new reader.
- `unlisted_private_channel_stays_private_and_opens_unlisted`: a private
unlisted channel is not readable by name, and opening it keeps the flag.
- `group_metadata_publishes_the_stored_unlisted_flag`, plus the unit
test `publishes_the_unlisted_flag_as_stored`.
- `unlisted_channel_artifacts_are_read_by_name_for_non_members`.
- `channel_created_unlisted_is_never_listed`: creating through
`create_channel_with_event` (the kind:9007 path) and
`create_labeled_channel` stores the flag, and the channel is never
listed to a non-member.
- Mutation-checked: each of `NOT unlisted` in the implicit scope, `NOT
c.unlisted` in the channel list, the unlisted branch of the named-only
query, its `visibility = 'open'` guard, and the artifact condition was
removed one at a time, and each removal failed at least one of these
tests.

Relay E2E (`test_nip29_unlisted_channel_wire`, added to the CI relay E2E
step), against a local relay built from this branch:
- A non-member or an unknown value is refused.
- kind:39000 by `#d` carries `unlisted` and `public`, and not `hidden`.
- kind:39000 discovery without `#d`: non-members don't see the channel,
members do.
- History and NIP-50 search: unnamed, a non-member doesn't see the
channel's messages; with `#h`, they do; a member sees them unnamed.
- A kind:9021 join works, and the joiner then lists the channel.
- Listing it again shows it to everyone.
- A reader whose channel set was cached before each change sees the
change at once. I ran this against a relay with the cache invalidation
removed, and it failed.

Relay E2E (`test_nip29_solo_share_and_convert_wire`, added to the CI
relay E2E step), each flow as a single event:
- kind:9007 with an unknown `unlisted` value is refused. A chat created
with `unlisted true` publishes the flag, and stays unlisted after a
plain `visibility open`.
- Share (open + unlisted + `join_role guest` in one kind:9002): a
non-member doesn't list the chat. They read it by `#h`, both history and
a live message, and can't post. A kind:9021 join lists it for them as a
read-only guest. A kind:9022 leave unlists it again, and it stays
readable by `#h`.
- Unshare (`visibility private`): the viewer's live subscription gets
CLOSED, and a new `#h` read is refused.
- Convert (`["t", ""]` + `unlisted false`): the Solo label is cleared,
and a non-member finds the chat in discovery.
- I ran this against a relay that dropped the kind:9007 flag, and it
failed.

Also run: `cargo test` for buzz-db, buzz-sdk, buzz-cli, buzz-core,
buzz-relay and buzz-test-client; the Postgres lane for buzz-db and
buzz-relay (1045 tests); and the existing unlisted, announce, departure,
guest, role-change and NIP-43 snapshot wire tests. In the lane, two
tests failed on pool timeouts
(`resend_validated_after_the_first_commit_is_a_duplicate`,
`edit_replaces_and_clears_labels`) and passed when rerun alone. An
earlier run had the same kind of flake:
`routed_fallback_spends_one_acquire_budget_when_aurora_cache_is_cold` (a
timing budget) and `resent_edit_is_a_duplicate` (a pool timeout). In a
full local `e2e_relay` run, three tests outside CI's list also failed
(`test_invite_*` twice,
`test_unarchive_emits_member_added_notification`). They fail the same
way on a relay built from `main`.

## Not in this PR

- The buzz-app follow-up: support open Solo chats, the join-from-card
view, the large-audience prompt, and gating on `buzz-unlisted-channels`.
- A NIP-CL update. The behavior is documented in NOSTR.md ("Unlisted
channels").





buzz-review-completed

---------

Signed-off-by: Bradley Axen <baxen@squareup.com>
Signed-off-by: Luke Tornquist <tornquist@squareup.com>
Co-authored-by: ART <ea39c1c8acf57180161ef4ba4ed68abf8589f5291956b909a5aa991fc66664ca@buzz.block.builderlab.xyz>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: mbot <3754f8729004d95654c46dbab3129e4ab9ef05cc2534e2a3fbfc155983bd637b@buzz.block.builderlab.xyz>
Co-authored-by: Luke Tornquist <tornquist@squareup.com>
Co-authored-by: Elrond <28d6302a099e5225b02c4155ac4236e4912603df2ab08dbfc2f4fef08ce598c8@buzz.block.builderlab.xyz>
2026-10-26 14:03:07 -04:00
..
…
…
…