buzz/NOSTR.md

Using Third-Party Nostr Clients with Buzz

Buzz is a Nostr relay that speaks NIP-29 (relay-based groups) natively. Third-party Nostr clients connect directly to buzz-relay using NIP-29 and NIP-42 authentication. The old NIP-28 compatibility proxy has been removed.

Community scope

Buzz treats the relay URL/domain as authoritative for the community. Today's single-relay deployment has exactly one community behind that URL, so existing NIP-29 clients keep using the same WebSocket URL, event kinds, tags, and HTTP/media/git paths. In a multi-community deployment, each community is reached by its own domain or subdomain; the backend resolves the community from the host before handling AUTH, EVENT, REQ, REST, media, git, search, or workflow traffic.

The Nostr wire format does not grow a tenant tag. Client-supplied #h tags still name channels/groups and are checked against the host-derived community. Events without #h — profiles, gift-wrapped DMs, membership notifications, lists, status, long-form notes, workflow/system events, and other "global" streams — are global only inside the connected community. A pubkey can join multiple communities and repost its profile in each one; DMs and profiles do not inherit across community domains.

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NIP-29 Direct

Connect any NIP-29 client straight to the relay.

Quick Start

# 1. (Optional) Enable pubkey allowlist — must be set BEFORE relay startup
export BUZZ_PUBKEY_ALLOWLIST=true

# 2. Start the relay (auto-starts Docker services and runs migrations)
just relay &                         # relay on :3000

# 3. Add a pubkey to the allowlist (if enabled)
#    Insert directly — there is no CLI command for this yet.
PGPASSWORD=buzz_dev psql -h localhost -U buzz -d buzz -c \
  "INSERT INTO pubkey_allowlist (pubkey) VALUES (decode('<64-char-hex-pubkey>', 'hex'))"

# 4. Connect any NIP-29 + NIP-42 client to ws://localhost:3000

What Works

Feature	Status	Notes
Group chat (kind:9)	✅	Send/receive messages with #h <channel-uuid> tag
Reactions (kind:7)	✅	Standard NIP-25; channel derived from target event's #e tag (client #h ignored)
Deletions (kind:5)	✅	Standard NIP-09; self-authored only. #h optional, #e required
User profiles (kind:0)	✅	NIP-01 metadata; synced to users table (display_name, avatar, about, NIP-05). NIP-05 handles must canonicalize to this relay's domain — off-domain or invalid handles are silently cleared. If a NIP-05 handle collides with another user's (UNIQUE constraint), the handle is skipped but other profile fields (display_name, avatar, about) are still synced.
Group creation (kind:9007)	✅	NIP-29; include name tag, optional visibility, channel_type, label t and unlisted tags
Add user (kind:9000)	✅	Open: any user, subject to target's channel_add_policy (owner_only/nobody can block). Private: owner/admin only. Self-add bypasses agent policy but not private-channel auth. A guest cannot add anyone. A new member with no role tag gets the channel's join_role; a non-member adding themselves may ask for join_role or a lower role. One event may name up to 100 people: one p tag each, with an optional role as the p tag's third element (NIP-29), falling back to the event's role tag. Each person is checked and added on their own. When the event names several people, the OK message is members: followed by JSON listing the non-empty added, updated (role changed), already_member and rejected ([{"reason", "pubkeys"}]) results. The event is refused only when it is malformed or nobody it names may be added; then one person keeps the single-add error, and several get invalid: members: {…}. The event and its membership changes are stored together, so an error: rejection stores nothing and the same event can be resent; a resent stored event returns duplicate: without results. Re-adding someone at their current role posts no second member_joined notice.
Remove user (kind:9001)	✅	Self-remove allowed (with last-owner guard). Removing others: owner/admin only.
Edit group metadata (kind:9002)	✅	name/about/label t/visibility/ttl/archived/join_role/unlisted tags: owner/admin. topic/purpose tags: any member except a guest. Buzz applies 9002 as a partial update: an absent tag leaves that setting unchanged.
Admin delete event (kind:9005)	✅	Event author can always delete own. Otherwise owner/admin required. Target must be in same channel.
Group deletion (kind:9008)	✅	Owner only.
Leave group (kind:9022)	✅	Any member. Last-owner guard prevents orphaned groups.
Group metadata (kind:39000)	✅	Relay-signed; always d, name, t, P, created_at, join_role; public or private; restricted and closed per the access flags below; unlisted when the channel is unlisted; about only if description non-empty; hidden for DM channels and private system channels
Unlisted channels	✅	kind:9002 ["unlisted", "true"|"false"], owner/admin, or at creation on kind:9007. An unlisted open channel is left out of every read that does not name it, for non-members: channel lists, kind:39000 without #d, messages, COUNT, NIP-50 search and artifact queries. Naming it by #h (or #d on 39000–39003) reads it, and kind:9021 joins it, as for any open channel. See Unlisted channels.
Group admins (kind:39001)	✅	Relay-signed; d, channel type t and creator P tags + p tags with roles (owner, admin)
Group members (kind:39002)	✅	Relay-signed; d, channel type t and creator P tags + p tags for all members
Membership notifications	✅	kind:44100 (added) / kind:44101 (removed); relay-signed, community-global scope (channel_id=None inside the connected community)
Presence (kind:20001)	✅	Ephemeral; arbitrary status string (truncated to 128 chars); writes to Redis (set_presence/clear_presence on "offline"), then fan-out to local subscribers. In multi-community mode presence is scoped to the connected community.
Agent presence (kind:20003)	✅	Ephemeral; an owner's presence for the agents it owns, named by p tags (at most 256); online/away set and offline clears each agent's presence as its own kind:20001 would. Not fanned out.
Typing indicators (kind:20002)	✅	Ephemeral, not stored; published via Redis pub/sub (multi-node capable unlike presence fan-out)
NIP-42 authentication	✅	Proactive challenge; optional pubkey allowlist
NIP-11 relay info	✅	GET / with Accept: application/nostr+json
Blossom media	✅	PUT /media/upload (BUD-02), GET /media/{sha256}.{ext} (BUD-01)
NIP-50 search	✅	One-shot search REQs: {"search":"query","kinds":[9],"#h":["<uuid>"]} → relevance-sorted results → EOSE. Not registered as persistent subscriptions. HTTP POST /query also accepts search_sort: "newest" (advertised as buzz-search-sort in NIP-11 supported_extensions) for newest-first results, paged with page.
NIP-10 threads	✅	WS-submitted replies with ["e","<root>","","reply"] tags create thread_metadata atomically. Visible in REST thread queries. Unknown parents rejected.
NIP-17 DMs (gift wrap)	✅	kind:1059 accepted with ephemeral signing keys. Stored community-globally (channel_id=None inside the connected community). Delivered via #p-filtered subscriptions. Not indexed in search.
DM discovery	✅	DM creation emits kind:39000 (with hidden tag) + kind:44100 membership notifications. NIP-29 clients discover DMs via standard group discovery flow.
Join request (kind:9021)	✅	Open channels only. Adds the joiner with the channel's join_role (member by default), emits system message + group discovery events + kind:44100 membership notification. Private channels rejected at ingest.
Edits (kind:40003)	⚠️	Works on the wire but Buzz-only — no standard NIP-29 client renders these
Rich content (kind:40002)	⚠️	Works on the wire but Buzz-only — no standard NIP-29 client renders these

What Doesn't Work

Feature	Status	Why
Create invite (kind:9009)	⚠️	Accepted and stored, but side-effect handler is deferred (no-op with warning log)
Group roles (kind:39003)	❌	Defined in kind registry but not emitted by the relay
DMs	⚠️	NIP-17 gift wraps supported; NIP-04/NIP-44 not implemented. kind:10050 (DM relay list) deferred.

Pubkey Allowlist

When BUZZ_PUBKEY_ALLOWLIST=true, NIP-42 connections that authenticate with only a pubkey (no API token) are checked against the pubkey_allowlist table. This lets you open the relay to specific external Nostr identities without granting full access.

• Users with valid API tokens bypass the allowlist.
• Fail-closed: if the DB lookup fails, the connection is denied.
• Default: false (all authenticated pubkeys accepted).
• Auth failure returns generic auth-required: verification failed (no allowlist-specific message).
• Manage the allowlist via direct SQL (no CLI command yet):

  INSERT INTO pubkey_allowlist (pubkey) VALUES (decode('<64-char-hex-pubkey>', 'hex'));
  DELETE FROM pubkey_allowlist WHERE pubkey = decode('<64-char-hex-pubkey>', 'hex');
  SELECT encode(pubkey, 'hex'), added_at, note FROM pubkey_allowlist;
  

Announce channels

Roles have the same permissions in every channel. A channel's settings decide only who can join and which role a new person gets:

• visibility (open | private) decides who can find, join and read.
• join_role (member | guest) is the role a person gets when nobody picks one: a self-join (kind:9021, or a kind:9000 self-add), or a kind:9000 add with no role tag. The default, member, keeps today's behavior.

An open channel with join_role = guest is an announce channel: anyone can find, read and join it, but people who join are guests and cannot write.

What each role can do:

Action	Guest	Member or bot	Admin / owner
Read, leave	Yes	Yes	Yes
Post, reply, edit, delete own, react, artifacts, canvas, forum, pins, typing, workflow messages, huddles	No	Yes	Yes
Topic, purpose (kind:9002)	No	Yes	Yes
Add people (kind:9000)	No	Yes, as member, guest or bot	Yes, any role
Push to the channel's git repositories	No	Yes	Yes
Name, about, visibility, TTL, join_role, unlisted	No	No	Yes

A non-member may write only where joining would give a role that can write: an open channel with join_role = member. A refused write gets restricted: only members can post in this channel.

Other rules:

• A non-member adding themselves with kind:9000 may ask for join_role or a lower role. A higher role is refused.
• Any member who can write (member, bot, owner or admin) can make a guest a member with kind:9000 (role member). This is the same for a person and an agent. Only owners and admins can make any other role change.
• The human owner of an agent can edit (kind:40003) and delete (kind:9005) that agent's messages, also as a guest or a non-member. This is existing behavior. It lets a person correct or remove what their agent posted; it does not let them post.
• Owners and admins change the setting with kind:9002 ["join_role", "guest"] or ["join_role", "member"]. A missing tag means "no change". Changing it does not change anyone's role: existing members can still write after a change to guest, and existing guests stay read-only after a change to member. A stored value the relay does not know is treated as guest.

kind:39000 publishes the NIP-29 access flags from these settings, and an explicit ["join_role", ...] tag so clients can tell what joining gives:

visibility	join_role	private	public	restricted	closed
open	member		✓
open	guest		✓	✓
private	either	✓		✓	✓

Unlisted channels

An unlisted open channel works like a link-shared document: anyone in the community who has its id (for example from a shared link) can read it and join it, but it does not show up for people who are not members.

• Owners and admins set it with kind:9002 ["unlisted", "true"] and clear it with ["unlisted", "false"]. A missing tag means "no change". It can be sent in the same event as ["visibility", "open"], so a private channel becomes open and unlisted in one step.
• kind:9007 also takes ["unlisted", "true"|"false"], so a channel can start unlisted; a missing tag means listed. Any other value is refused before the event is stored, as on kind:9002.
• For a non-member, an unlisted open channel, of any type, is left out of every read that does not name it: a filter without #h (including kind:39000 discovery without #d, and the system-channel opt-in by #P or #t:["system"]), COUNT, NIP-50 search, artifact queries and the channel list. A filter that names it by #h, or by #d on a filter whose kinds are all 39000–39003, reads it under the ordinary open-channel rules. This is the same "named-only" rule that applies to system channels (NIP-CL).
• Joining (kind:9021) and posting work as on any open channel; join_role still decides what a joiner gets.
• Members see it everywhere, as before.
• The flag is stored on its own and matters only while the channel is open. Private channels are already invisible to non-members. A private channel can be marked unlisted ahead of time, so opening it later never lists it.
• kind:39000 carries a bare ["unlisted"] flag whenever the setting is on, whatever the visibility. It does not add NIP-29 hidden: the metadata stays readable by id.
• Relays that support it advertise buzz-unlisted-channels in NIP-11 supported_extensions. An older relay applies ["visibility", "open"] and ignores unlisted, so a client must check for it before opening a channel as unlisted.
• Unlisted is not an access control. Anyone with the id can read the channel.

Group Discovery

The relay emits NIP-29 group state events when channels are created, updated, or membership changes. NIP-CL defines the channel identity tags on these events and how clients use them to find channels. All discovery events include a d tag set to the channel UUID (NIP-29 addressable event convention):

Kind	Tags	Content
39000	d=<uuid>, name, t=<channel_type>, P=<creator>, created_at=<unix seconds>, join_role (always); public or private; restricted (private channels, and join_role=guest); closed (private channels only); unlisted (unlisted channels); about (if description non-empty); hidden (DM channels and private system channels)	Group metadata. The access flags follow the channel settings (see Announce channels).
39001	d=<uuid>, t=<channel_type>, P=<creator>, p tags with role label (owner, admin)	Admin list
39002	d=<uuid>, t=<channel_type>, P=<creator>, p tags for all members	Member list

On all three kinds the channel type t tag comes first, then one t tag per channel label, then P. Clients read the first t value as the channel type. P is the public key that signed the channel's kind:9007. The relay writes it from the database, and it does not change when ownership moves. Uppercase P follows NIP-22, NIP-34 and NIP-72, where it names the author of the root object; lowercase p already lists members and DM participants on these kinds.

kind:39000 also carries ["created_at", <unix seconds>]: the time the channel was created. The event's own created_at is the time of the last edit, so use the tag to find the older of two channels.

Channel labels. A label groups channels across channel types, for example ["t", "workspace"]. Set labels with ["t", <label>] tags on kind:9007. On kind:9002 the t tags replace the whole set, and ["t", ""] with no other t tag clears it; a kind:9002 without t tags leaves the labels as they are. Only an owner or admin may change labels. The relay refuses a label set with more than 8 distinct labels, a label that is not 1-64 characters from a-z, 0-9, ., : and -, or a label equal to a channel type name (stream, forum, dm, workflow, system).

System channels. A channel with channel_type system exists only for access control, for example to hold config that only an agent and its owner can read. It is an ordinary channel in every other way, but queries leave it out unless they ask for it:

• A filter that does not name it, for example a REQ with no #h, a COUNT, a NIP-50 search, or kind:39002 #p:[me], does not return it. Such a filter returns only the legacy channel types (stream, forum, dm, workflow), so a channel type added later is also left out.
• A filter that names it with #h, or with #d on kinds 39000–39003, reads it under the ordinary rules: the reader is a member, or it is open. A channel of a type added later is read the same way.
• A filter on kinds 39000–39003 with #t:["system"] or any #P also returns the system channels the reader can read, then matches as usual. It does not return channels of a type added later. For example, {kinds:[39000], #P:[<creator>], #t:[<label>]} finds one creator's labeled channel, system or not. Values in one tag filter combine with OR, so #t:["system", <label>] does not mean "a system channel with this label".

Push notifications use the same rule: a lease filter pushes events from a system channel only when its #h names that channel. Every kind:44100/44101 membership notification carries its channel type as t, and a filter without #t sees only the legacy types, so system channel notices reach only a filter with #t:["system"] (see NIP-CL).

Events are stored channel-scoped so access control applies — private channel member lists are only visible to members. Discover groups via historical REQ:

# All groups you can see
nak req -k 39000 --auth --sec <privkey> ws://localhost:3000

# Specific group's members (filter by d tag)
nak req -k 39002 --tag "d=<channel-uuid>" --auth --sec <privkey> ws://localhost:3000

Note: Channel-scoped storage means live global subscriptions ({kinds:[39000]}) won't receive these via fan-out. Clients discover groups via historical REQ queries. Live push for open-channel discovery is a future enhancement.

Membership Notifications

The relay emits relay-signed notifications when members are added or removed:

Kind	Meaning	Tags	Scope
44100	Member added	p = target pubkey, h = channel UUID	Community-global
44101	Member removed	p = target pubkey, h = channel UUID	Community-global

Each notice also has t = the channel type (stream, forum, dm, workflow, system). A filter with #t gets only the types it names. A filter without #t gets only stream, forum, dm and workflow, and so does an untagged notice stored before the tag existed (NIP-CL).

Stored community-globally (channel_id = None inside the connected community) so agents and clients can subscribe without knowing channel UUIDs in advance. Client-submitted kind:44100/44101 events are rejected — only the relay keypair may sign these.

Subscription constraint: Global REQs that can match p-gated kinds (44100, 44101, 1059) must include a #p filter where all #p values match the authenticated pubkey. The relay rejects subscriptions that omit #p or include other pubkeys (prevents eavesdropping on others' membership changes and DMs). Error: restricted: p-gated events require #p matching your pubkey.

nak req -k 44100 -k 44101 --tag "p=<your-hex-pubkey>" \
  --auth --sec <privkey> ws://localhost:3000

Sending Messages

# Send a kind:9 message
nak event -k 9 -c "Hello from NIP-29!" --tag "h=<channel-uuid>" \
  --auth --sec <privkey> ws://localhost:3000

# Subscribe to channel messages
nak req -k 9 --tag "h=<channel-uuid>" --stream \
  --auth --sec <privkey> ws://localhost:3000

# React to a message (#h optional but recommended; channel derived from #e target)
nak event -k 7 -c "+" --tag "h=<channel-uuid>" --tag "e=<message-event-id>" \
  --auth --sec <privkey> ws://localhost:3000

# Subscribe to reactions to channel messages — include #h for live delivery (see note below)
nak req -k 7 --tag "h=<channel-uuid>" --stream \
  --auth --sec <privkey> ws://localhost:3000

# Delete a message (#h optional; #e required; must be self-authored)
nak event -k 5 -c "reason" --tag "h=<channel-uuid>" --tag "e=<message-event-id>" \
  --auth --sec <privkey> ws://localhost:3000

# Create a group
nak event -k 9007 --tag "name=my-channel" --tag "visibility=open" \
  --auth --sec <privkey> ws://localhost:3000

# Search messages (NIP-50)
nak req -k 9 --tag "h=<channel-uuid>" --search "search query" -l 20 \
  --auth --sec <privkey> ws://localhost:3000

# Reply to a message (NIP-10 threading)
nak event -k 9 -c "Reply text" --tag "h=<channel-uuid>" \
  --tag "e=<parent-event-id>;;reply" \
  --auth --sec <privkey> ws://localhost:3000

# Fetch gift-wrapped DMs (NIP-17)
nak req -k 1059 --tag "p=<your-hex-pubkey>" \
  --auth --sec <privkey> ws://localhost:3000

Note: The relay derives a reaction's channel from its #e target (client #h is ignored for channel determination). Reactions to channel-scoped events are therefore channel-scoped. Live fan-out keeps channel-scoped and global subscriptions strictly separate, which means a kinds-only subscription ({"kinds":[7]}) receives none of those reactions — subscribe with {"kinds":[7],"#h":["<channel-uuid>"]} instead. #h matching works whether or not the signed reaction carries an h tag: explicit h tags are matched directly, and tagless reactions match via their stored channel.

Tested Clients (Direct)

Client	Platform	Evidence	Notes
BuzzTestClient	Rust (repo)	Automated E2E	Full NIP-29 flow: discovery (39000/39001/39002), kind:9 send/receive, reactions, deletions, h-tag enforcement
E2E nostr interop	Rust (repo)	Automated E2E	NIP-50 search (3 tests), NIP-10 threads (3 tests), NIP-17 gift wraps (3 tests), DM discovery (1 test)
nak	CLI	Manual (verified)	kind:9 send/recv, NIP-50 search, NIP-10 thread replies, group discovery

Not verified in-repo (anecdotal / expected based on NIP-29 support):

• Chachi (Web/Mobile) — NDK-based; NIP-29 native
• 0xchat (Mobile) — NIP-29 native

---

Relay Membership (NIP-43)

When BUZZ_REQUIRE_RELAY_MEMBERSHIP=true, every authenticated connection is checked against the relay_members table. In today's single-community deployment this is the relay-wide member list; in multi-community mode the same rule is scoped to the host-derived community. Only pubkeys with a row for that community may use that community. The relay owner is bootstrapped automatically from RELAY_OWNER_PUBKEY on startup.

CLI: Managing Members

Use buzz-admin — the operator CLI shipped in the relay image — to manage relay membership. In a Docker Compose deployment, use run.sh:

# Add a member (accepts bech32 npub or 64-char hex; default role: member)
./run.sh add-member npub1abc...
./run.sh add-member <64-char-hex-pubkey>
./run.sh add-member npub1abc... --role admin

# Remove a member
./run.sh remove-member npub1abc...
./run.sh remove-member npub1abc... --role member   # only removes if role matches

# List all members
./run.sh list-members

Or invoke buzz-admin directly inside the container:

docker compose exec relay buzz-admin add-member --pubkey npub1abc...
docker compose exec relay buzz-admin add-member --pubkey npub1abc... --role admin
docker compose exec relay buzz-admin remove-member --pubkey npub1abc...
docker compose exec relay buzz-admin list-members
# Rewrite the kind:13534 member list from the stored members (repairs a missing or stale list)
# Repairs only the community RELAY_URL maps to; on a multi-community relay, run it once per community host
docker compose exec relay buzz-admin republish-members

Exit codes:

Code	Meaning
0	Success
1	Validation error (bad pubkey, bad role, usage error)
2	Not found (remove: member does not exist)
3	Cannot remove relay owner (use RELAY_OWNER_PUBKEY to change owner)
4	Role mismatch (--role check failed)
5	DB/Redis/internal error

Required environment variables for member management:

Variable	Notes
DATABASE_URL	Postgres connection string
REDIS_URL	Redis connection string
BUZZ_RELAY_PRIVATE_KEY	Hex private key — required to sign kind:13534 events

NIP-43 Admin Events (WebSocket)

Relay membership can also be managed over WebSocket using NIP-43 admin events. These require the sender to be authenticated (NIP-42) as the relay owner or an admin.

Kind	Action	Required tags
9030	Add member	["p", "<hex-pubkey>"], optional ["role", "member|admin"]
9031	Remove member	["p", "<hex-pubkey>"], optional ["role", "member|admin"]
9032	Change role	["p", "<hex-pubkey>"], ["role", "member|admin"]
9033	Set workspace profile (icon)	["icon", "<https-url or data:image/* URL>"] (empty clears)

Example using nak:

# Add a member (owner or admin must sign)
nak event -k 9030 \
  --tag "p=<target-hex-pubkey>" \
  --tag "role=member" \
  --auth --sec <owner-or-admin-privkey> \
  ws://localhost:3000

# Remove a member
nak event -k 9031 \
  --tag "p=<target-hex-pubkey>" \
  --auth --sec <owner-or-admin-privkey> \
  ws://localhost:3000

# Change a member's role to admin
nak event -k 9032 \
  --tag "p=<target-hex-pubkey>" \
  --tag "role=admin" \
  --auth --sec <owner-or-admin-privkey> \
  ws://localhost:3000

After each add/remove/role-change, the relay publishes a kind:13534 membership list event (relay-signed, NIP-70 protected) that clients can subscribe to:

# Subscribe to the live membership roster
nak req -k 13534 --auth --sec <privkey> ws://localhost:3000

A kind:9033 command similarly makes the relay store the workspace icon (per community) and serve it in the standard NIP-11 icon field of its relay information document. Clients render it in the workspace rail/switcher; anyone can read it (curl -H 'Accept: application/nostr+json' http://localhost:3000), but only admins/owners can set it. Full spec: docs/nips/NIP-WP.md.

Known Limitations

1. CLI intentionally does not emit kind 8000/8001 deltas — publish_nip43_delta is in-process-only (no Redis hop), so a sidecar call stores but never pushes. The 13534 list snapshot is the authoritative roster and rides Redis to live clients. Do not wire a delta call that passes in-process tests and silently no-ops in the deployed compose exec path.

2. The custom_created_at = max(now, newest_existing_13534 + 1s) bump defeats same-second domination for serial invocations; it does NOT serialize concurrent CLI processes — two near-simultaneous adds can read the same newest timestamp and collide on the bumped second. run.sh serialization is the guard against parallel adds (e.g. xargs -P). When adding multiple members in a loop, add sleep 1 between invocations.

---

Relay Environment Variables (NIP-29 relevant)

Variable	Required	Default	Description
BUZZ_PUBKEY_ALLOWLIST	❌	false	Enable pubkey allowlist for NIP-42 pubkey-only auth
BUZZ_RELAY_PRIVATE_KEY	❌	random	Hex secret key for relay signing (discovery events, system messages)
BUZZ_REQUIRE_AUTH_TOKEN	❌	false	Require authenticated NIP-42 for all connections

---

Security Notes

Direct Path

• Pubkey allowlist is fail-closed. DB errors deny the connection.
• API token users bypass the allowlist. The allowlist only gates pubkey-only NIP-42.
• kind:9 requires #h tag. Messages without a channel-scoped #h tag are rejected.
• kind:7 derives channel from target. Reactions look up the target event's channel via #e — client-supplied #h tags are ignored. Reactions to unknown events are rejected (fail-closed).
• kind:5 uses #h if present, but doesn't require it. Deletions validate author-match against target events via #e tags. Only self-authored events can be deleted (admin deletions use kind:9005).
• Client-submitted kind:44100/44101 rejected. Membership notifications can only be signed by the relay keypair.

---

Troubleshooting

Direct Path

Symptom	Cause	Fix
auth-required: verification failed	Pubkey not in allowlist (when enabled), or NIP-42 auth failed	Add pubkey to pubkey_allowlist table; verify NIP-42 challenge/response
invalid: channel-scoped events must include an h tag	kind:9 sent without #h tag	Include --tag "h=<channel-uuid>"
invalid: reaction target event not found	Reaction references unknown event	Ensure the target event exists in the relay
No discovery events	Channel is private + you're not a member	Join the channel first

---

Further Reading

• nostr-protocol/nips — the upstream NIP specifications (NIP-01, NIP-29, NIP-42, and the other NIPs referenced throughout this guide).
• docs/nips/ — Buzz's own NIP extension documents.
• ARCHITECTURE.md — event kinds, wire protocol, and relay internals.