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.

---

## NIP-29 Direct

Connect any NIP-29 client straight to the relay.

### Quick Start

```bash
# 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` and label `t` 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. |
| **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` tags: owner/admin. `topic`/`purpose` tags: any member. |
| **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`, `closed`, `["t", <channel_type>]`, `["P", <creator>]` and `["created_at", <unix seconds>]` tags; `about` only if description non-empty; `private` if applicable; `hidden` for DM channels and private system 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. |
| **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 member, 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):
  ```sql
  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;
  ```

### Group Discovery

The relay emits NIP-29 group state events when channels are created, updated, or membership changes.
[NIP-CL](docs/nips/NIP-CL.md) 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`, `closed`, `t=<channel_type>`, `P=<creator>`, `created_at=<unix seconds>` (always); `about` (if description non-empty); `private` (if applicable); `hidden` (DM channels and private system channels) | Group metadata. **Note:** `closed` is always emitted per NIP-29 convention (Buzz channels require explicit membership), but open channels are still readable/writable by non-members at runtime. The tag reflects the membership model, not access enforcement. |
| **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.
- 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 filter on kinds 39000–39003 with `#t:["system"]` or any `#P` also
  returns the system channels the reader can read, then matches as usual.
  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 and kind:44100/44101 membership notifications skip system channels.

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

```bash
# 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 |

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`.

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

### Sending Messages

```bash
# 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`:

```bash
# 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:

```bash
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
```

**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`:

```bash
# 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:

```bash
# 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](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](https://github.com/nostr-protocol/nips) — the upstream NIP specifications (NIP-01, NIP-29, NIP-42, and the other NIPs referenced throughout this guide).
- [`docs/nips/`](docs/nips/) — Buzz's own NIP extension documents.
- [`ARCHITECTURE.md`](ARCHITECTURE.md) — event kinds, wire protocol, and relay internals.