diff --git a/changelog.d/904-guest-sees-host-bots.fixed.md b/changelog.d/904-guest-sees-host-bots.fixed.md
new file mode 100644
index 00000000..5c474330
--- /dev/null
+++ b/changelog.d/904-guest-sees-host-bots.fixed.md
@@ -0,0 +1 @@
+A group joined through an invite link now lists the host's Bots instead of only your own: the join notice carries the host room's Bot roster, the Members card shows each Bot by name and owner, and a message keeps the Bot that wrote it. A Bot the host has not connected to Bot Social shows as "Not connected", and a host Bot this side cannot confirm yet shows as "Unconfirmed" rather than as a friend's Bot.
diff --git a/core/client.js b/core/client.js
index 49294e71..2fcb42e4 100644
--- a/core/client.js
+++ b/core/client.js
@@ -190,6 +190,8 @@ var ZH = {
   Retry: "重试",
   Approve: "批准",
   "Friend's Bot": "好友的 Bot",
+  "Unconfirmed": "未确认",
+  "Not connected": "未接入",
   "Expand": "展开",
   "Collapse": "收起",
   "Setting up your Main Bot…": "正在设置你的主 Bot…",
@@ -12574,9 +12576,12 @@ function GroupSettingsForm({ room: room2, roster, actions, run, onDeleted }) {
           { className: "bt-gs-who" },
           (0, import_react30.createElement)(BotAvatar, { bot: lookBotForRemote(person, roster), size: 26, badge: false, live: false }),
           (0, import_react30.createElement)("span", { className: "bt-row-title", title: person.handle || void 0 }, person.label || remoteBotTitle(person)),
-          room2.origin === "face-to-face" ? null : (0, import_react30.createElement)("span", { className: "bt-tag" }, t("Friend's Bot"))
+          // #904: a host's roster entry is not a friend's Bot, and one this home cannot confirm is
+          // labelled as such; a Bot with no Bot Social identity can never be written to at all.
+          room2.origin === "face-to-face" ? null : (0, import_react30.createElement)("span", { className: "bt-tag" }, person.unconnected ? t("Not connected") : room2.origin === "inbound-share" && person.verified === false ? t("Unconfirmed") : t("Friend's Bot"))
         ),
-        room2.origin === "face-to-face" || members.length + remotes.length <= 2 ? null : (0, import_react30.createElement)("button", { type: "button", className: "bt-x", "aria-label": t("Remove {name} from the group", { name: remoteBotTitle(person) }), title: t("Remove from group"), onClick: () => update({ removeParticipants: [{ kind: "bot", id: person.handle || person.id, remote: true }] }) }, "×")
+        // A guest's mirror is not theirs to edit: the host's membership is changed on the host side.
+        room2.origin === "face-to-face" || room2.origin === "inbound-share" || members.length + remotes.length <= 2 ? null : (0, import_react30.createElement)("button", { type: "button", className: "bt-x", "aria-label": t("Remove {name} from the group", { name: remoteBotTitle(person) }), title: t("Remove from group"), onClick: () => update({ removeParticipants: [{ kind: "bot", id: person.handle || person.id, remote: true }] }) }, "×")
       )),
       room2.origin === "face-to-face" ? null : adding ? [
         ...outsidePeople.map((person) => (0, import_react30.createElement)(
diff --git a/core/src/client/group-settings.js b/core/src/client/group-settings.js
index 7d6ba2ac..95cfcacb 100644
--- a/core/src/client/group-settings.js
+++ b/core/src/client/group-settings.js
@@ -186,8 +186,14 @@ export function GroupSettingsForm({ room, roster, actions, run, onDeleted }) {
         h('span', { className: 'bt-gs-who' },
           h(BotAvatar, { bot: lookBotForRemote(person, roster), size: 26, badge: false, live: false }),
           h('span', { className: 'bt-row-title', title: person.handle || undefined }, person.label || remoteBotTitle(person)),
-          room.origin === 'face-to-face' ? null : h('span', { className: 'bt-tag' }, t('Friend\'s Bot'))),
-        room.origin === 'face-to-face' || members.length + remotes.length <= 2
+          // #904: a host's roster entry is not a friend's Bot, and one this home cannot confirm is
+          // labelled as such; a Bot with no Bot Social identity can never be written to at all.
+          room.origin === 'face-to-face' ? null
+            : h('span', { className: 'bt-tag' }, person.unconnected ? t('Not connected')
+              : room.origin === 'inbound-share' && person.verified === false ? t('Unconfirmed')
+                : t('Friend\'s Bot'))),
+        // A guest's mirror is not theirs to edit: the host's membership is changed on the host side.
+        room.origin === 'face-to-face' || room.origin === 'inbound-share' || members.length + remotes.length <= 2
           ? null
           : h('button', { type: 'button', className: 'bt-x', 'aria-label': t('Remove {name} from the group', { name: remoteBotTitle(person) }), title: t('Remove from group'), onClick: () => update({ removeParticipants: [{ kind: 'bot', id: person.handle || person.id, remote: true }] }) }, '×'))),
       room.origin === 'face-to-face' ? null : adding
diff --git a/core/src/client/i18n.js b/core/src/client/i18n.js
index a109bad5..df96f30f 100644
--- a/core/src/client/i18n.js
+++ b/core/src/client/i18n.js
@@ -154,6 +154,8 @@ const ZH = {
   Retry: '重试',
   Approve: '批准',
   "Friend's Bot": '好友的 Bot',
+  'Unconfirmed': '未确认',
+  'Not connected': '未接入',
   'Expand': '展开',
   'Collapse': '收起',
   'Setting up your Main Bot…': '正在设置你的主 Bot…',
diff --git a/core/src/host/room-membership.js b/core/src/host/room-membership.js
index ffda33ad..e7cd2d7f 100644
--- a/core/src/host/room-membership.js
+++ b/core/src/host/room-membership.js
@@ -691,6 +691,7 @@ export function install(rt) {
       syncMembers(room)
       await rt.save()
       if (record?.remote && record.handle) void rt.notifyRoomShare?.(room, { op: 'join', handle: record.handle })
+      else if (record?.kind === 'bot' && !record.remote) reshareRoster(room)
       return room
     })
   }
@@ -708,7 +709,9 @@ export function install(rt) {
         throw forbidden('Only a room admin can remove participants')
       }
       const live = currentParticipants(room)
-      const botsLeft = live.filter(p => p.kind === 'bot' && p.id !== me.id && p.handle !== me.handle)
+      // A local Bot has no handle: comparing handles alone dropped every local Bot from the count, so
+      // removing one always tripped the two-Bot rule. Compare by handle only when the entry has one.
+      const botsLeft = live.filter(p => p.kind === 'bot' && p.id !== me.id && (!me.handle || p.handle !== me.handle))
       const ownerLeave = actor && (
         (kind === 'human' && me.id === actor.memberId)
         || (kind === 'bot' && (state.bots?.[me.id]?.ownerId === actor.memberId || me.ownerId === actor.memberId || room.sharedFrom?.ownerId === actor.memberId))
@@ -735,6 +738,8 @@ export function install(rt) {
           .catch(error => rt.warn?.('ds-bot: a seat\'s leave was not settled: %s', error))
       } else if (kind === 'bot' && room.origin === 'inbound-share' && room.sharedFrom?.ticket) {
         void leaveTicketRoom(room, me).catch(error => rt.warn?.('ds-bot: leaving %s was not sent: %s', room.name, error))
+      } else if (kind === 'bot' && !me.remote) {
+        reshareRoster(room)
       }
       return room
     })
@@ -953,6 +958,172 @@ export function install(rt) {
     }
   }
 
+  // #904: a guest's copy learns this home's membership only from a fresh roster. A local add or remove
+  // therefore has to send one; without this the guest list never changes and a removed Bot keeps writing.
+  function reshareRoster(room) {
+    if (!room || room.origin === 'inbound-share' || isFaceRoom(room)) return
+    if (!(room.participants ?? []).some(p => p.remote)) return
+    void Promise.resolve(rt.notifyRoomShare?.(room, { op: 'join' }))
+      .catch(error => rt.warn?.('ds-bot: a membership change was not shared: %s', error))
+  }
+
+  // #904: the Bots this home keeps in the room, for the guests' copies of it. Only this home's own Bots:
+  // another guest's Bot is not this home's to publish. A Bot with no Bot Social identity rides along as
+  // `connected: false` so the guest can show it as not connected instead of leaving it out entirely.
+  function roomRoster(room) {
+    const out = []
+    for (const p of currentParticipants(room)) {
+      if (p.kind !== 'bot' || p.remote) continue
+      const bot = state.bots?.[p.id]
+      const member = bot?.fields?.social?.member
+      const handle = typeof member?.handle === 'string' && /^@[A-Za-z0-9._-]{1,120}$/.test(member.handle) ? member.handle : undefined
+      const name = bot?.name || p.displayName || p.id
+      const ownerName = ownerNameSafe(p) || cleanPeerName(member?.ownerName, '')
+      // #904: (home, handle) is the identity a guest keys on; a handle alone is unique only inside a home.
+      const home = typeof member?.home === 'string' && /^@[A-Za-z0-9._-]{1,120}$/.test(member.home) ? member.home : ''
+      const homeField = home ? { home } : {}
+      out.push(handle ? { handle, name, ...homeField, ...(ownerName ? { ownerName } : {}) } : { name, ...homeField, ...(ownerName ? { ownerName } : {}) })
+    }
+    return out
+  }
+
+  // #904: a roster is text a stranger wrote. It is read only for the room this mirror is bound to and
+  // only from that room's own inviter; anything else is dropped whole. Every entry it names stays
+  // unverified unless this home already holds a fact about that handle (the seat that carried the join,
+  // or a published friend Bot) — an unverified entry is displayed, never addressed.
+  function rosterOf(data, room, event) {
+    if (!Array.isArray(data?.roster)) return undefined
+    const bound = room?.sharedFrom ?? {}
+    const same = (a, b) => {
+      const left = String(a ?? '').trim().toLowerCase()
+      return left !== '' && left === String(b ?? '').trim().toLowerCase()
+    }
+    if (!same(data.roomId, bound.remoteRoomId)) return undefined
+    if (bound.inviterHome && bound.inviterHandle) {
+      if (!same(event?.fromHome, bound.inviterHome) || !same(event?.fromHandle, bound.inviterHandle)) return undefined
+    } else if (bound.inviterHome ? !same(event?.fromHome, bound.inviterHome) : !same(event?.fromHandle, bound.inviterHandle)) return undefined
+    const seat = String(bound.invitedHandle ?? '')
+    const out = []
+    for (const entry of data.roster.slice(0, 32)) {
+      const name = cleanPeerName(entry?.name, '')
+      const ownerName = cleanPeerName(entry?.ownerName, '')
+      const handle = String(entry?.handle ?? '').trim()
+      // The entry's home is identity, not trust: verification stays on the transport's home.
+      const entryHome = String(entry?.home ?? '').trim()
+      const ownerHome = /^@[A-Za-z0-9._-]{1,120}$/.test(entryHome) ? entryHome : bound.inviterHome
+      if (!handle) {
+        if (name) out.push({ name, ownerName, ownerHome, connected: false })
+        continue
+      }
+      if (!/^@[A-Za-z0-9._-]{1,120}$/.test(handle)) continue
+      out.push({
+        handle,
+        ownerHome,
+        name: name || handle,
+        ownerName,
+        verified: (handle === seat && same(ownerHome, bound.inviterHome)) || Boolean(publishedRemoteOf(state, handle)),
+      })
+    }
+    return out
+  }
+
+  // #904: the host room's notice rides the join like the roster (the guest's group settings were empty).
+  // It is stranger-written text too, so it is read only for the room this mirror is bound to and only
+  // from that room's own inviter; an empty value is not encoded, so it never wipes a notice.
+  function noticeOf(data, room, event) {
+    if (data?.op !== 'join' || typeof data.notice !== 'string') return undefined
+    const text = data.notice.replace(/[\u0000-\u001f\u007f-\u009f]/g, ' ').trim().slice(0, 2000)
+    const bound = room?.sharedFrom ?? {}
+    const same = (a, b) => {
+      const left = String(a ?? '').trim().toLowerCase()
+      return left !== '' && left === String(b ?? '').trim().toLowerCase()
+    }
+    if (bound.remoteRoomId && !same(data.roomId, bound.remoteRoomId)) return undefined
+    if (bound.inviterHome && !same(event?.fromHome, bound.inviterHome)) return undefined
+    if (bound.inviterHandle && !same(event?.fromHandle, bound.inviterHandle)) return undefined
+    return text
+  }
+
+  // #904: one remote participant per roster entry. A roster is the whole list, so an entry it drops is a
+  // Bot the host no longer keeps here: it leaves this mirror's list, and nothing of it stays addressable.
+  function applyRoster(room, entries) {
+    if (!Array.isArray(entries)) return false
+    let changed = false
+    const seen = new Set()
+    const seat = String(room.sharedFrom?.invitedHandle ?? '')
+    const boundHome = room.sharedFrom?.inviterHome
+    const sameHome = (a, b) => {
+      const left = String(a ?? '').trim().toLowerCase()
+      return left !== '' && left === String(b ?? '').trim().toLowerCase()
+    }
+    const at = Date.now()
+    for (const entry of entries) {
+      const key = entry.handle || `not-connected:${entry.name.toLowerCase()}`
+      const ownerHome = entry.ownerHome || boundHome
+      seen.add(key)
+      // #904: one entry per (home, handle), so a same-named Bot of another home is a different Bot.
+      const found = (room.participants ?? []).find(p => p.remote && (p.handle === key || p.id === key)
+        && (!entry.handle || sameHome(p.ownerHome ?? boundHome, ownerHome)))
+      if (found) {
+        if (found.leftSeq !== undefined) {
+          delete found.leftSeq
+          delete found.leftAt
+          changed = true
+        }
+        if (entry.name && found.displayName !== entry.name) {
+          found.displayName = entry.name
+          changed = true
+        }
+        if (entry.ownerName && found.ownerName !== entry.ownerName) {
+          found.ownerName = entry.ownerName
+          changed = true
+        }
+        if (entry.handle && entry.handle === seat && found.verified !== true) {
+          found.verified = true
+          changed = true
+        }
+        continue
+      }
+      room.participants = [...(room.participants ?? []), entry.handle ? {
+        kind: 'bot',
+        remote: true,
+        id: entry.handle,
+        handle: entry.handle,
+        ownerHome,
+        ownerName: entry.ownerName,
+        displayName: entry.name,
+        role: 'member',
+        fromRoster: true,
+        verified: entry.verified === true,
+        roomOnly: true,
+        joinedSeq: room.seq ?? 0,
+        joinedAt: at,
+      } : {
+        kind: 'bot',
+        remote: true,
+        id: key,
+        unconnected: true,
+        ownerName: entry.ownerName,
+        displayName: entry.name,
+        role: 'member',
+        fromRoster: true,
+        verified: false,
+        roomOnly: true,
+        joinedSeq: room.seq ?? 0,
+        joinedAt: at,
+      }]
+      changed = true
+    }
+    for (const p of room.participants ?? []) {
+      if (!p.fromRoster || p.leftSeq !== undefined) continue
+      if (seen.has(p.handle || p.id)) continue
+      p.leftSeq = room.seq ?? 0
+      p.leftAt = at
+      changed = true
+    }
+    return changed
+  }
+
   // Membership notice: the add/remove click is the owner's consent, so this does not wait
   // for a chat line. Bot Social is 1:1; the envelope is the group record the other FlyBot sees.
   rt.notifyRoomShare = async function notifyRoomShare(room, { op = 'join', handle } = {}) {
@@ -973,6 +1144,7 @@ export function install(rt) {
           invitedHandle: remote.handle,
           seq: room.seq ?? 0,
           ticket: remote.ticket,
+          ...(op === 'join' ? { roster: roomRoster(room), notice: room.notice || '' } : {}),
           ...seat.from,
         }, 'room-share', seat.botId, room.id)
         continue
@@ -984,6 +1156,7 @@ export function install(rt) {
         name: room.name,
         invitedHandle: remote.handle,
         seq: room.seq ?? 0,
+        ...(op === 'join' ? { roster: roomRoster(room), notice: room.notice || '' } : {}),
         ...from,
       }, 'room-share')
     }
@@ -1477,6 +1650,9 @@ export function install(rt) {
     const who = cleanPeerName(data.who, remoteBotTitle(seat))
     const hop = Number.isFinite(Number(data.hop)) ? Math.max(0, Math.floor(Number(data.hop))) : 0
     const human = data.authorKind !== 'bot'
+    // #904: this path never reads the envelope's `authorId`: `ownSeatOf` matched the seat by the
+    // transport's own `fromHandle`, so `seat.handle` is already the Bot that wrote the line, while a
+    // claim inside the envelope is only the guest's word. A guest cannot speak as another Bot here.
     const posted = append(room, rt.authoredRoomLine(room, {
       who,
       text: data.text || '',
@@ -1767,8 +1943,17 @@ export function install(rt) {
     const sender = String(event.fromHandle ?? '')
     if (!claim) return sender ? { authorId: sender, authorKind: 'bot' } : { authorId: undefined, authorKind: 'human' }
     if (!claim.startsWith('@')) return { authorId: claim, authorKind: kind }
+    // #904: a remote seat stands for the handle only when this home verified it and it belongs to the
+    // home the transport names: two homes may carry the same handle, and an unverified roster entry is a
+    // display fact, never a signature.
+    const sameHome = (left, right) => {
+      const a = String(left ?? '').trim().toLowerCase()
+      return a !== '' && a === String(right ?? '').trim().toLowerCase()
+    }
     const traced = claim === sender
-      || currentParticipants(room).some(p => p.remote === true && (p.handle === claim || p.id === claim))
+      || currentParticipants(room).some(p => p.remote === true && p.leftSeq === undefined
+        && p.verified === true && (p.handle === claim || p.id === claim)
+        && sameHome(p.ownerHome ?? room.sharedFrom?.inviterHome, event.fromHome))
       || room.sharedFrom?.inviterHandle === claim
     return traced ? { authorId: claim, authorKind: kind } : { authorId: sender || claim, authorKind: 'bot', unverified: true }
   }
@@ -1894,6 +2079,8 @@ export function install(rt) {
         remoteRoomId: data.roomId,
         joinedSeq: data.seq,
         ...(ticket && data.op === 'join' ? { ticket } : {}),
+        ...(data.op === 'join' ? { roster: rosterOf(data, { sharedFrom: { remoteRoomId: data.roomId, inviterHome: event.fromHome, inviterHandle: event.fromHandle, invitedHandle: data.invitedHandle } }, event) } : {}),
+        ...(typeof noticeOf(data, undefined, event) === 'string' ? { notice: noticeOf(data, undefined, event) } : {}),
       }, actor || (ownerId ? { memberId: ownerId } : undefined))
     } else {
       delete room.hidden
@@ -1914,11 +2101,15 @@ export function install(rt) {
         }]
         room.sharedFrom = { ...room.sharedFrom, ticket }
       }
-      for (const p of room.participants ?? []) {
-        if (seatedHere && p.id !== localBotId) continue
-        if (p.leftSeq !== undefined) {
-          delete p.leftSeq
-          delete p.leftAt
+      // #904: only a join brings anyone back. A line on an existing mirror must not clear the soft leaves
+      // a roster just set, or a plain message would quietly undo a removal.
+      if (data.op === 'join') {
+        for (const p of room.participants ?? []) {
+          if (seatedHere && p.id !== localBotId) continue
+          if (p.leftSeq !== undefined) {
+            delete p.leftSeq
+            delete p.leftAt
+          }
         }
       }
       if (data.name) room.name = cleanPeerName(data.name, room.name)
@@ -1932,6 +2123,11 @@ export function install(rt) {
         invitedHandle: data.invitedHandle || room.sharedFrom?.invitedHandle,
         remoteRoomId: data.roomId,
       }
+      // #904: the host re-sends the whole roster when its membership changes, so this list is the
+      // current one; a Bot it no longer names leaves this mirror.
+      applyRoster(room, data.op === 'join' ? rosterOf(data, room, event) : undefined)
+      const notice = noticeOf(data, room, event)
+      if (typeof notice === 'string') room.notice = notice
       syncMembers(room)
     }
     let called = []
@@ -1980,6 +2176,10 @@ export function install(rt) {
     if (!ownerId) throw invalid('Sign in first')
     const handle = draft.invitedHandle || draft.handle
     const localBotId = draft.localBotId && state.bots?.[draft.localBotId] ? draft.localBotId : undefined
+    // #904: `invitedHandle` on this side names one of my own Bots (the share addressed it), so the
+    // host's Bot to record is the one that carried the join. A handle this home owns is never a remote.
+    const seatHandle = typeof draft.inviterHandle === 'string' && draft.inviterHandle.startsWith('@') ? draft.inviterHandle : undefined
+    const mineHandles = new Set(Object.values(state.bots ?? {}).map(bot => bot?.fields?.social?.member?.handle).filter(own => typeof own === 'string'))
     const at = Date.now()
     const inviterName = cleanPeerName(draft.inviterName, 'a friend')
     const title = cleanPeerName(draft.name, sharedRoomTitle(inviterName))
@@ -2026,7 +2226,35 @@ export function install(rt) {
           joinedAt: draft.invitedAt ?? at,
           invitedByName: inviterName,
           invitedAt: draft.invitedAt ?? at,
-        }] : handle ? [{
+        }] : []),
+        // #904: the host's seat Bot is a participant of its own, not the alternative to mine. A guest
+        // always brings a Bot (`localBotId`), so the old either/or dropped the host's side whole — the
+        // reported "they cannot see my Bots". The seat is the Bot that carried the join (the inviter),
+        // never `invitedHandle`: on this side that is one of my own Bots. It keeps the shape a ticket
+        // seat has here (#884).
+        ...(seatHandle && !mineHandles.has(seatHandle) ? [{
+          kind: 'bot',
+          remote: true,
+          id: seatHandle,
+          handle: seatHandle,
+          ownerHome: draft.inviterHome,
+          ownerName: inviterName,
+          displayName: cleanPeerName(draft.inviterBotName, seatHandle),
+          role: 'member',
+          ...(typeof draft.ticket === 'string' && draft.ticket ? { admittedBy: 'ticket', ticket: draft.ticket } : {}),
+          verified: true,
+          roomOnly: true,
+          joinedSeq: draft.joinedSeq ?? 0,
+          joinedAt: draft.invitedAt ?? at,
+          invitedByName: inviterName,
+          invitedAt: draft.invitedAt ?? at,
+          ownerId,
+        }] : []),
+        // The friend path's remote Bot: a share that names a Bot of another home and brought none of
+        // mine. The either/or this replaces kept one of the two, and a share may legitimately name both.
+        // When this home brought a Bot, `invitedHandle` names one of my own Bots (the share addressed it):
+        // recording it as remote would list my own Bot twice, once under each name.
+        ...(handle && handle !== seatHandle && !mineHandles.has(handle) && !(localBotId && handle === draft.invitedHandle) ? [{
           kind: 'bot',
           remote: true,
           id: handle,
@@ -2035,6 +2263,8 @@ export function install(rt) {
           ownerName: inviterName,
           displayName: cleanPeerName(draft.botName, handle),
           role: 'member',
+          verified: true,
+          roomOnly: true,
           joinedSeq: draft.joinedSeq ?? 0,
           joinedAt: draft.invitedAt ?? at,
           invitedByName: inviterName,
@@ -2044,6 +2274,10 @@ export function install(rt) {
       ],
     }
     state.rooms[id] = room
+    // #904: the notice the join carried (gated by the caller) is the room's own notice.
+    if (typeof draft.notice === 'string') room.notice = draft.notice
+    // #904: the roster the join carried, merged on top of the two above (the seat is already there).
+    if (applyRoster(room, draft.roster)) syncMembers(room)
     await rt.save?.()
     return room
   }
diff --git a/core/src/shared/room-share.js b/core/src/shared/room-share.js
index 0edf88c4..818bde3f 100644
--- a/core/src/shared/room-share.js
+++ b/core/src/shared/room-share.js
@@ -14,6 +14,27 @@ function clip(value, max = 60) {
   return String(value ?? '').replace(/[\u0000-\u001f\u007f-\u009f]/g, ' ').trim().slice(0, max)
 }
 
+// #904: a room's roster entry. A Bot inside a real room is a handful, not a crowd; the cap keeps one
+// envelope from turning into a member dump a guest has to render.
+export const ROSTER_MAX = 32
+// The group notice's own limit in the room editor (core/src/client/group-settings.js).
+export const NOTICE_MAX = 2000
+
+// #904: a handle is unique only inside its home, so an entry carries the home it belongs to: two homes
+// can keep Bots with the same local name, and a guest has to tell them apart when it attributes a line.
+// The receiving side verifies against the transport's home; this field is for identity, not for trust.
+function rosterEntry(entry = {}) {
+  const handle = clip(entry.handle, 120)
+  const home = clip(entry.home, 120)
+  const out = { name: clip(entry.name) }
+  if (handle) out.handle = handle
+  if (/^@[A-Za-z0-9._-]{1,120}$/.test(home)) out.home = home
+  const ownerName = clip(entry.ownerName)
+  if (ownerName) out.ownerName = ownerName
+  if (!handle) out.connected = false
+  return out
+}
+
 export function encodeRoomShare(payload = {}) {
   const body = {
     v: 1,
@@ -49,6 +70,18 @@ export function encodeRoomShare(payload = {}) {
   if (Array.isArray(payload.calls) && payload.calls.length > 0) {
     body.calls = payload.calls.map(handle => clip(handle, 120)).filter(Boolean).slice(0, 24)
   }
+  // #904: the host room's Bots ride the membership notice so the guest's mirror can list them. It is
+  // display data only — the guest still takes reachability from Bot Social, so a roster can never hand
+  // out a send path. `connected: false` is a Bot with no Bot Social identity: shown, never addressed.
+  // #904: an explicit roster is encoded even when empty — empty means the host keeps none of its Bots in
+  // the room any more, while an absent field means "change nothing" (an older host).
+  if (body.op === 'join' && Array.isArray(payload.roster)) {
+    body.roster = payload.roster.slice(0, ROSTER_MAX).map(rosterEntry).filter(entry => entry.connected === false || entry.handle)
+  }
+  // #904: the host room's notice rides the same join envelope, so the guest's group settings are not
+  // empty. It is text the room displays, never authority. A present notice is encoded even when empty:
+  // empty means the host cleared it, while an absent field means "change nothing" (an older host).
+  if (body.op === 'join' && typeof payload.notice === 'string') body.notice = clip(payload.notice, NOTICE_MAX)
   return `${ROOM_SHARE_MARK}\n${JSON.stringify(body)}`
 }
 
diff --git a/core/test/remote-room.test.js b/core/test/remote-room.test.js
index c39880f6..e58bf7a9 100644
--- a/core/test/remote-room.test.js
+++ b/core/test/remote-room.test.js
@@ -1575,3 +1575,390 @@ test('#909: a line is never shown under a handle the room cannot trace', async (
   assert.equal(own.authorId, '@chief.alice.home')
   assert.equal(own.unverified, undefined)
 })
+
+
+// #904: a guest who joins with a link always brings a Bot, and the participants list treated the local
+// Bot and the host's seat Bot as alternatives. The host's side was therefore dropped whole: the guest's
+// room listed themselves and their own Bot, nothing of the host's — the reported "they cannot see my Bots".
+test('#904: a link join keeps the host\'s seat Bot beside the guest\'s own', async (t) => {
+  const { rt } = host(t, TEAM)
+  await rt.load()
+  const { bob } = await signAliceAndBob(rt)
+  const actorB = await rt.authenticate(bob.sessionToken)
+  const room = await rt.recordInboundSharedRoom({
+    id: 'from-alice',
+    name: 'War room',
+    inviterName: 'Alice',
+    inviterHome: '@alice.home',
+    inviterHandle: '@chief.alice.home',
+    invitedHandle: '@spec.b.bob.home',
+    localBotId: 'spec-b',
+    remoteRoomId: 'alice-war',
+    joinedSeq: 2,
+    ticket: 'AbCdEfGhIjKlMnOpQrStUv',
+  }, actorB)
+  const bots = room.participants.filter(p => p.kind === 'bot')
+  assert.deepEqual(bots.filter(p => !p.remote).map(p => p.id), ['spec-b'], 'the guest\'s own Bot stays')
+  const seat = bots.find(p => p.remote)
+  assert.ok(seat, 'the host\'s seat Bot is recorded too, not only the guest\'s Bot')
+  assert.equal(seat.handle, '@chief.alice.home', 'the Bot that carried the join, never the invited handle')
+  assert.equal(seat.admittedBy, 'ticket', 'the seat keeps the shape a ticket seat has')
+  assert.equal(seat.roomOnly, true, 'a seat is reachable inside the room it was admitted to, nowhere else')
+  assert.equal(seat.verified, true)
+  // The report's "Members · 2" is You + your own Bot, and the badge on it is the guest's own Bot: admin is
+  // `localBotId` alone, so a host Bot becoming a participant must not take the badge with it.
+  assert.equal(room.participants.length, 3, 'you, your own Bot, and the host seat: three')
+  assert.equal(room.admin, 'spec-b', 'the guest\'s own Bot stays the admin of its mirror')
+  assert.equal(seat.role, 'member', 'the host seat is a member, never the admin')
+  // The fix lands in `participants` only: `room.members` is what speaks, leads and renders, and a remote
+  // handle there would hand the guest a member of its own group.
+  assert.deepEqual(room.members, ['spec-b'], 'the room members stay local; a remote is never a member')
+})
+
+// #904: the join notice carries the host room's Bot roster, and the guest lists every Bot in it. What a
+// roster decides is who is displayed: an entry this home cannot confirm stays unverified and unreachable.
+test('#904: a join roster lists every host Bot, and a line keeps the Bot that wrote it', async (t) => {
+  const { rt } = host(t, TEAM)
+  await rt.load()
+  const { bob } = await signAliceAndBob(rt)
+  const actorB = await rt.authenticate(bob.sessionToken)
+  // A published friend Bot in the roster is a fact this home holds, so that entry is verified.
+  publish(rt, [{ ...CODER, handle: '@writer.a.home', name: 'Writer A', home: '@alice.home', homeName: 'Alice', owner: 'Alice' }])
+  const join = encodeRoomShare({
+    op: 'join', roomId: 'alice-war', name: 'War room', inviterName: 'Alice',
+    inviterHome: '@alice.home', inviterHandle: '@chief.alice.home', invitedHandle: '@chief.b.alice.home', seq: 4,
+    notice: 'Be nice to each other.',
+    roster: [
+      { handle: '@chief.a.home', home: '@alice.home', name: 'Chief A', ownerName: 'Alice' },
+      { handle: '@chief.b.alice.home', home: '@alice.home', name: 'Chief B', ownerName: 'Alice' },
+      { handle: '@writer.a.home', home: '@alice.home', name: 'Writer A', ownerName: 'Alice' },
+      { handle: '@ghost.alice.home', home: '@alice.home', name: 'Ghost', ownerName: 'Alice' },
+      { name: 'Offline Bot', ownerName: 'Alice' },
+    ],
+  })
+  assert.equal(parseRoomShare(join).roster.length, 5, 'the roster rides the existing envelope')
+  const first = await rt.applyInboundRoomShare({
+    fromHandle: '@chief.alice.home', fromHome: '@alice.home', fromName: 'Alice',
+    text: join, localBotId: 'spec-b',
+  }, actorB)
+  const room = first.room
+  assert.equal(room.notice, 'Be nice to each other.', 'the group notice rides the join, so the guest\'s settings are not empty')
+  const live = room.participants.filter(p => p.leftSeq === undefined)
+  const handles = live.filter(p => p.kind === 'bot' && p.remote).map(p => p.handle ?? p.id).sort()
+  assert.deepEqual(handles, [
+    '@chief.a.home', '@chief.alice.home', '@chief.b.alice.home', '@ghost.alice.home', '@writer.a.home', 'not-connected:offline bot',
+  ], 'every Bot the host named is listed, and the guest\'s own Bot is not the only one')
+  const seat = live.find(p => p.handle === '@chief.b.alice.home')
+  assert.equal(seat.verified, true, 'the seat that carried the join is this home\'s own fact')
+  assert.equal(live.find(p => p.handle === '@chief.a.home').ownerHome, '@alice.home', 'the roster entry carries the home its handle is unique in')
+  const named = live.find(p => p.handle === '@writer.a.home')
+  assert.equal(named.displayName, 'Writer A')
+  assert.equal(named.ownerName, 'Alice', 'the guest can tell whose Bot it is')
+  assert.equal(named.verified, true, 'a published friend Bot is this home\'s own fact')
+  const ghost = live.find(p => p.handle === '@ghost.alice.home')
+  assert.equal(ghost.verified, false, 'a name in a stranger\'s roster is not proof')
+  assert.equal(named.roomOnly, true, 'a roster never widens reach')
+  const offline = live.find(p => p.unconnected === true)
+  assert.equal(offline.displayName, 'Offline Bot')
+  assert.equal(offline.handle, undefined, 'a Bot with no identity has no handle to write to')
+  // The client reads these through presentRoom, which keeps the whole live list.
+  const shown = presentRoom(rt.state.rooms[room.id], actorB, rt.state)
+  assert.equal(shown.presentedParticipants.filter(p => p.remote).length, 6)
+
+  // A line keeps the Bot that wrote it — not the seat, not the inviter — when the roster holds it.
+  const line = encodeRoomShare({
+    op: 'line', roomId: 'alice-war', inviterName: 'Alice', inviterHome: '@alice.home',
+    inviterHandle: '@chief.b.alice.home', invitedHandle: '@chief.b.alice.home', seq: 5,
+    who: 'Writer A', authorKind: 'bot', authorId: '@writer.a.home', text: 'on it',
+  })
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: line, localBotId: 'spec-b' }, actorB)
+  const posted = room.log.filter(entry => String(entry.text).includes('on it')).at(-1)
+  assert.equal(posted.authorId, '@writer.a.home')
+  assert.equal(posted.botId, '@writer.a.home')
+
+  // A line that names a Bot this room never verified is said by the inviter, never by that Bot.
+  const forged = encodeRoomShare({
+    op: 'line', roomId: 'alice-war', inviterName: 'Alice', inviterHome: '@alice.home',
+    inviterHandle: '@chief.b.alice.home', invitedHandle: '@chief.b.alice.home', seq: 6,
+    who: 'Ghost', authorKind: 'bot', authorId: '@nobody.home', text: 'not me',
+  })
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: forged, localBotId: 'spec-b' }, actorB)
+  const forgedLine = room.log.filter(entry => String(entry.text).includes('not me')).at(-1)
+  assert.equal(forgedLine.authorId, '@chief.alice.home', 'an invented author never speaks as another Bot')
+
+  // A line that names an unverified roster entry is said by the inviter, never by that Bot.
+  const fromGhost = encodeRoomShare({
+    op: 'line', roomId: 'alice-war', inviterName: 'Alice', inviterHome: '@alice.home',
+    inviterHandle: '@chief.b.alice.home', invitedHandle: '@chief.b.alice.home', seq: 7,
+    who: 'Ghost', authorKind: 'bot', authorId: '@ghost.alice.home', text: 'not verified',
+  })
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: fromGhost, localBotId: 'spec-b' }, actorB)
+  const ghostLine = room.log.filter(entry => String(entry.text).includes('not verified')).at(-1)
+  assert.equal(ghostLine.authorId, '@chief.alice.home', 'an unverified roster entry never speaks under its own name')
+
+  // A Bot handle is a Bot's line: calling it a person's line in the envelope does not make it one, and an
+  // unverified handle is still said by the Bot that carried the line and marked unverified.
+  const humanClaim = encodeRoomShare({
+    op: 'line', roomId: 'alice-war', inviterName: 'Alice', inviterHome: '@alice.home',
+    inviterHandle: '@chief.b.alice.home', invitedHandle: '@chief.b.alice.home', seq: 8,
+    who: 'Ghost', authorKind: 'human', authorId: '@ghost.alice.home', text: 'as a person',
+  })
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: humanClaim, localBotId: 'spec-b' }, actorB)
+  const asPerson = room.log.filter(entry => String(entry.text).includes('as a person')).at(-1)
+  assert.equal(asPerson.authorKind, 'bot', 'a Bot handle never becomes a person because the envelope says so')
+  assert.equal(asPerson.authorId, '@chief.alice.home', 'and it is the Bot that carried the line that said it')
+  assert.equal(asPerson.unverified, true, 'the claim it failed to prove is marked unverified')
+  assert.equal(asPerson.botId, '@chief.alice.home')
+
+  // A verified Bot's own line needs no marker, and neither does a person's line from the other home.
+  const person = encodeRoomShare({
+    op: 'line', roomId: 'alice-war', inviterName: 'Alice', inviterHome: '@alice.home',
+    inviterHandle: '@chief.b.alice.home', invitedHandle: '@chief.b.alice.home', seq: 9,
+    who: 'Alice', authorKind: 'human', authorId: 'owner-a', text: 'a person here',
+  })
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: person, localBotId: 'spec-b' }, actorB)
+  const said = room.log.filter(entry => String(entry.text).includes('a person here')).at(-1)
+  assert.equal(said.authorKind, 'human')
+  assert.equal(said.authorId, 'owner-a')
+  assert.equal(said.unverified, undefined, 'a person\'s line from that home is not a Bot claim')
+
+  // The host's next roster is the current one: the Bots it no longer names leave this mirror.
+  const shrunk = encodeRoomShare({
+    op: 'join', roomId: 'alice-war', name: 'War room', inviterName: 'Alice',
+    inviterHome: '@alice.home', inviterHandle: '@chief.b.alice.home', invitedHandle: '@chief.b.alice.home', seq: 7,
+    roster: [
+      { handle: '@chief.a.home', name: 'Chief A', ownerName: 'Alice' },
+      { handle: '@chief.b.alice.home', name: 'Chief B', ownerName: 'Alice' },
+    ],
+  })
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: shrunk, localBotId: 'spec-b' }, actorB)
+  const after = room.participants.filter(p => p.leftSeq === undefined)
+  assert.deepEqual(after.filter(p => p.kind === 'bot' && p.remote).map(p => p.handle).sort(), ['@chief.a.home', '@chief.alice.home', '@chief.b.alice.home'], 'the seat that carried the join is not roster-controlled; the two it dropped are gone')
+  assert.equal(after.some(p => p.id === 'spec-b'), true, 'the guest\'s own Bot is not host-controlled')
+  // #904: identity is (home, handle). A Bot of another home is a different Bot even when the name
+  // matches, so a line it did not send cannot borrow its name here. The envelope itself cannot arrive
+  // from a home this room is not bound to at all (#909 refuses that before any attribution).
+  room.participants.push({
+    kind: 'bot', remote: true, id: '@chief.dup.home', handle: '@chief.dup.home', ownerHome: '@bob.home',
+    ownerName: 'Bob', displayName: 'Dup', role: 'member', verified: true, roomOnly: true, joinedSeq: 0, joinedAt: 1,
+  })
+  const crossHome = encodeRoomShare({
+    op: 'line', roomId: 'alice-war', inviterName: 'Alice', inviterHome: '@alice.home',
+    inviterHandle: '@chief.b.alice.home', invitedHandle: '@chief.b.alice.home', seq: 12,
+    who: 'Dup', authorKind: 'bot', authorId: '@chief.dup.home', text: 'cross home',
+  })
+  const intruder = await rt.applyInboundRoomShare({ fromHandle: '@chief.bob.home', fromHome: '@bob.home', text: crossHome, localBotId: 'spec-b' }, actorB)
+  assert.equal(intruder.refused, 'not-inviter', 'a home this room is not bound to cannot write into it')
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: crossHome, localBotId: 'spec-b' }, actorB)
+  const cross = room.log.filter(entry => String(entry.text).includes('cross home')).at(-1)
+  assert.equal(cross.authorId, '@chief.alice.home', 'another home\'s Bot name is not this room\'s Bot')
+  assert.equal(cross.unverified, true)
+
+  // A removed entry is a soft leave, not a deletion: its history stays resolvable.
+  const left = room.participants.filter(p => p.leftSeq !== undefined).map(p => p.handle || p.id).sort()
+  assert.deepEqual(left, ['@ghost.alice.home', '@writer.a.home', 'not-connected:offline bot'], 'a roster drop marks the entry left instead of deleting it')
+
+  // A line must not bring a removed Bot back: only a join does, so a removal cannot be undone by
+  // whoever keeps talking in the room.
+  const afterRemoval = encodeRoomShare({
+    op: 'line', roomId: 'alice-war', inviterName: 'Alice', inviterHome: '@alice.home',
+    inviterHandle: '@chief.b.alice.home', invitedHandle: '@chief.b.alice.home', seq: 6,
+    who: 'Alice', authorKind: 'human', authorId: 'owner-a', text: 'after removal',
+  })
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: afterRemoval, localBotId: 'spec-b' }, actorB)
+  assert.deepEqual(room.participants.filter(p => p.leftSeq !== undefined).map(p => p.handle || p.id).sort(), left, 'a line does not resurrect a removed Bot')
+
+  // The same join redelivered changes nothing: no second entry, no second participant.
+  const count = room.participants.length
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: shrunk, localBotId: 'spec-b' }, actorB)
+  assert.equal(room.participants.length, count, 'a redelivered join adds no second entry')
+
+  // A Bot the host puts back comes back in place: the existing entry clears its soft leave, no duplicate.
+  const back = encodeRoomShare({
+    op: 'join', roomId: 'alice-war', name: 'War room', inviterName: 'Alice',
+    inviterHome: '@alice.home', inviterHandle: '@chief.b.alice.home', invitedHandle: '@chief.b.alice.home', seq: 8,
+    roster: [
+      { handle: '@chief.a.home', name: 'Chief A', ownerName: 'Alice' },
+      { handle: '@chief.b.alice.home', name: 'Chief B', ownerName: 'Alice' },
+      { handle: '@writer.a.home', name: 'Writer A', ownerName: 'Alice' },
+    ],
+  })
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: back, localBotId: 'spec-b' }, actorB)
+  assert.deepEqual(room.members, ['spec-b'], 'a roster never writes into the room members')
+  const writers = room.participants.filter(p => p.handle === '@writer.a.home')
+  assert.equal(writers.length, 1, 'a Bot that comes back reuses its entry')
+  assert.equal(writers[0].leftSeq, undefined, 'and its soft leave is cleared')
+
+  // The host edits its notice and clears it: both ride the same join. Clearing is a present empty
+  // field; an absent field (an older host) is not an instruction to change anything.
+  const edited = encodeRoomShare({
+    op: 'join', roomId: 'alice-war', name: 'War room', inviterName: 'Alice',
+    inviterHome: '@alice.home', inviterHandle: '@chief.b.alice.home', invitedHandle: '@chief.b.alice.home', seq: 10,
+    notice: 'Edited notice.',
+  })
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: edited, localBotId: 'spec-b' }, actorB)
+  assert.equal(room.notice, 'Edited notice.', 'an edited notice follows on the next join')
+  const cleared = encodeRoomShare({
+    op: 'join', roomId: 'alice-war', name: 'War room', inviterName: 'Alice',
+    inviterHome: '@alice.home', inviterHandle: '@chief.b.alice.home', invitedHandle: '@chief.b.alice.home', seq: 11,
+    notice: '',
+  })
+  assert.equal(parseRoomShare(cleared).notice, '', 'a cleared notice is still carried, as an empty field')
+  assert.equal(parseRoomShare(encodeRoomShare({ op: 'join', roomId: 'alice-war', name: 'War room' })).notice, undefined, 'no notice field means "change nothing"')
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: cleared, localBotId: 'spec-b' }, actorB)
+  assert.equal(room.notice, '', 'clearing the notice clears the guest\'s copy')
+
+  // #904: a join that carries no roster field is not a request to empty the list. An older host, or a
+  // peer that drops the field, leaves the guest's participants exactly as they are.
+  const bare = encodeRoomShare({
+    op: 'join', roomId: 'alice-war', name: 'War room', inviterName: 'Alice',
+    inviterHome: '@alice.home', inviterHandle: '@chief.b.alice.home', invitedHandle: '@chief.b.alice.home', seq: 9,
+  })
+  const kept = room.participants.map(p => p.id)
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: bare, localBotId: 'spec-b' }, actorB)
+  assert.deepEqual(room.participants.map(p => p.id), kept, 'a join without a roster field changes nothing')
+
+  // #904: an explicit empty roster clears this home's Bots from the mirror — the seat, my own Bot and the
+  // person stay. (An absent field, just above, changes nothing.)
+  const emptied = encodeRoomShare({
+    op: 'join', roomId: 'alice-war', name: 'War room', inviterName: 'Alice',
+    inviterHome: '@alice.home', inviterHandle: '@chief.b.alice.home', invitedHandle: '@chief.b.alice.home', seq: 13,
+    roster: [],
+  })
+  assert.deepEqual(parseRoomShare(emptied).roster, [], 'an explicit empty roster is encoded instead of dropped')
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: emptied, localBotId: 'spec-b' }, actorB)
+  assert.equal(room.participants.filter(p => p.fromRoster && p.leftSeq === undefined).length, 0, 'an empty roster leaves nobody of the host\'s from the roster')
+  assert.equal(room.participants.some(p => p.id === 'spec-b' && p.leftSeq === undefined), true, 'my own Bot is not controlled by the roster')
+  assert.equal(room.participants.some(p => p.handle === '@chief.alice.home' && p.leftSeq === undefined), true, 'the seat that carried the join stays')
+})
+
+// #904: a roster is stranger-written text, so the envelope that carries one is gated: only the room's
+// own inviter, only the room this mirror is bound to, and nothing it says widens reach by itself.
+test('#904: a roster from another home or for another room changes no participant', async (t) => {
+  const { rt } = host(t, TEAM)
+  await rt.load()
+  const { bob } = await signAliceAndBob(rt)
+  const actorB = await rt.authenticate(bob.sessionToken)
+  const join = {
+    op: 'join', roomId: 'alice-war', name: 'War room', inviterName: 'Alice',
+    inviterHome: '@alice.home', inviterHandle: '@chief.alice.home', invitedHandle: '@chief.b.alice.home', seq: 1,
+    notice: 'Alice\'s notice.',
+    roster: [{ handle: '@chief.a.home', name: 'Chief A', ownerName: 'Alice' }],
+  }
+  const first = await rt.applyInboundRoomShare({
+    fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: encodeRoomShare(join), localBotId: 'spec-b',
+  }, actorB)
+  const room = first.room
+  const before = room.participants.length
+
+  // Another home claims the same remote room id and names a Bot: the envelope is dropped whole.
+  const fromElsewhere = {
+    ...join, seq: 2, inviterHome: '@mallory.home', inviterHandle: '@mallory.home',
+    roster: [{ handle: '@mallory.bot.home', name: 'Mallory Bot', ownerName: 'Mallory' }],
+  }
+  await rt.applyInboundRoomShare({
+    fromHandle: '@mallory.home', fromHome: '@mallory.home', text: encodeRoomShare(fromElsewhere), localBotId: 'spec-b',
+  }, actorB)
+  assert.equal(rt.state.rooms[room.id].participants.length, before, 'a roster from a home that is not the inviter changes nothing')
+  assert.equal(rt.state.rooms[room.id].participants.some(p => p.handle === '@mallory.bot.home'), false)
+  assert.equal(rt.state.rooms[room.id].notice, "Alice's notice.", 'a joiner from another home does not rewrite the notice')
+
+  // A roster sent for another room id does not touch this mirror either.
+  const elsewhere = { ...join, roomId: 'other-room', seq: 3, notice: 'Mallory was here.', roster: [{ handle: '@eve.home', name: 'Eve', ownerName: 'Eve' }] }
+  await rt.applyInboundRoomShare({
+    fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: encodeRoomShare(elsewhere), localBotId: 'spec-b',
+  }, actorB)
+  assert.equal(rt.state.rooms[room.id].participants.some(p => p.handle === '@eve.home'), false, 'another room id opens no slot here')
+  assert.equal(rt.state.rooms[room.id].participants.length, before)
+  assert.equal(rt.state.rooms[room.id].notice, "Alice's notice.", 'a join for another room id does not rewrite the notice')
+})
+
+// #904: the host side of the same envelope. The membership notice names this home's Bots by name and
+// owner, and a Bot with no Bot Social identity rides as not connected instead of being left out.
+test('#904: the membership notice carries the room\'s own Bots, and one without an identity as not connected', async (t) => {
+  const { rt, sent } = host(t, TEAM)
+  await rt.load()
+  const { alice } = await signAliceAndBob(rt)
+  const actorA = await rt.authenticate(alice.sessionToken)
+  publish(rt)
+  await grantToFriend(rt, 'chief-a')
+  await grantToFriend(rt, 'chief-b')
+  rt.state.bots['chief-b'].ownerId = 'owner-1'
+  const room = rt.state.rooms.war
+  rt.state.bots['chief-a'].fields = { social: { member: { handle: '@chief.a.home', home: '@alice.home', ownerName: 'Alice' } } }
+  rt.state.bots['chief-b'].fields = { social: { member: { handle: '@chief.b.home', home: '@alice.home', ownerName: 'Alice' } } }
+  room.members.push('spec-a')
+  room.participants.push({ kind: 'bot', id: 'spec-a', role: 'member', displayName: 'Writer A', joinedSeq: 0, joinedAt: 1 })
+  room.participants.push({ kind: 'bot', remote: true, id: '@coder.bob.home', handle: '@coder.bob.home', ownerHome: '@bob.home', ownerName: 'Bob', displayName: 'Coder', role: 'member', joinedSeq: 0, joinedAt: 1 })
+
+  assert.equal(rt.state.bots['chief-a'].fields.social.member.home, '@alice.home', 'fixture home')
+  assert.equal(room.participants.some(p => p.id === 'chief-a'), true, 'chief-a is a participant')
+  await rt.notifyRoomShare(room, { op: 'join', handle: '@coder.bob.home' })
+  const notice = parseRoomShare(sent.at(-1).text)
+  // #904: removing or adding one of *this home's* Bots has to send a fresh roster; the guest's list
+  // otherwise never changes and a removed Bot keeps writing.
+  const joins = () => sent.filter(m => m.text.includes('"op":"join"'))
+  await rt.removeRoomParticipant('war', { kind: 'bot', id: 'chief-b' }, actorA)
+  await new Promise(resolve => setTimeout(resolve, 0))
+  const afterRemove = parseRoomShare(joins().at(-1).text)
+  assert.equal(afterRemove.roster.some(entry => entry.handle === '@chief.b.home'), false, 'a local remove re-sends the roster without the Bot')
+  await rt.addRoomParticipant('war', { kind: 'bot', id: 'chief-b' }, actorA)
+  await new Promise(resolve => setTimeout(resolve, 0))
+  const afterAdd = parseRoomShare(joins().at(-1).text)
+  assert.equal(afterAdd.roster.some(entry => entry.handle === '@chief.b.home'), true, 'a local add re-sends the roster with the Bot')
+  assert.equal(notice.op, 'join')
+  room.notice = 'Keep it short.'
+  await rt.notifyRoomShare(room, { op: 'join', handle: '@coder.bob.home' })
+  const withNotice = parseRoomShare(sent.at(-1).text)
+  assert.equal(withNotice.notice, 'Keep it short.', 'the join carries the room\'s notice')
+  assert.deepEqual(notice.roster.map(entry => entry.handle ?? entry.name).sort(), ['@chief.a.home', '@chief.b.home', 'Writer A'])
+  assert.equal(notice.roster.find(entry => entry.handle === '@chief.a.home').home, '@alice.home', 'a roster entry names the home its handle is unique in')
+  const a = notice.roster.find(entry => entry.handle === '@chief.a.home')
+  assert.deepEqual({ name: a.name, ownerName: a.ownerName }, { name: 'Chief A', ownerName: 'Alice' })
+  const offline = notice.roster.find(entry => !entry.handle)
+  assert.equal(offline.connected, false, 'a Bot with no identity is listed as not connected, not dropped')
+  assert.equal(notice.roster.some(entry => entry.handle === '@coder.bob.home'), false, 'another home\'s Bot is not this home\'s to publish')
+
+  // A leave says only that someone left; it carries no roster.
+  await rt.notifyRoomShare(room, { op: 'leave', handle: '@coder.bob.home' })
+  assert.equal(parseRoomShare(sent.at(-1).text).roster, undefined)
+})
+
+// #904: the seat path attributes a line to the seat that carried it and never to the envelope's own
+// `authorId`: `ownSeatOf` matched that seat by the transport's `fromHandle`, so the seat already is the
+// Bot that wrote the line, while a claim inside the envelope is only the guest's word. This guards the
+// reverse "fix" (trust the claim) that would let a guest speak as any Bot in this home.
+test('#904: a seat\'s line is attributed to the seat, not to whatever the envelope claims', async (t) => {
+  const { rt } = host(t, TEAM)
+  await rt.load()
+  const { alice } = await signAliceAndBob(rt)
+  const actorA = await rt.authenticate(alice.sessionToken)
+  const room = rt.state.rooms.war
+  const ticket = 'AbCdEfGhIjKlMnOpQrStUv'
+  room.participants.push({
+    kind: 'bot', remote: true, id: '@chief.bob.home', handle: '@chief.bob.home', ownerHome: '@bob.home', ownerName: 'Bob',
+    displayName: 'Chief', role: 'member', admittedBy: 'ticket', ticket, hostBotId: 'chief-a', joinedSeq: 0, joinedAt: 1,
+  })
+  const line = (authorId, seq) => encodeRoomShare({
+    op: 'line', roomId: 'war', inviterHome: '@bob.home', inviterHandle: '@chief.bob.home',
+    seq, who: 'Chief', authorKind: 'bot', authorId, text: 'line ' + seq,
+  })
+  const ingest = (authorId, seq) => rt.applyInboundRoomShare({
+    fromHandle: '@chief.bob.home', fromHome: '@bob.home', text: line(authorId, seq),
+  }, actorA)
+
+  // A Bot of this home is not the seat: the claim falls back to the seat that carried the line.
+  await ingest('@writer.a.home', 1)
+  const forged = room.log.filter(entry => String(entry.text).includes('line 1')).at(-1)
+  assert.equal(forged.authorId, '@chief.bob.home', 'a guest cannot speak as a Bot of this home')
+  assert.equal(forged.botId, '@chief.bob.home')
+  assert.equal(forged.via, '@chief.bob.home')
+
+  // The seat is the author, and an invented handle is not adopted either.
+  await ingest('@chief.bob.home', 2)
+  const own = room.log.filter(entry => String(entry.text).includes('line 2')).at(-1)
+  assert.equal(own.authorId, '@chief.bob.home')
+  await ingest('@ghost.nobody', 3)
+  const invented = room.log.filter(entry => String(entry.text).includes('line 3')).at(-1)
+  assert.equal(invented.authorId, '@chief.bob.home', 'an invented handle never becomes an author')
+})
diff --git a/core/test/room-ticket-seat.test.js b/core/test/room-ticket-seat.test.js
index 5bac8562..230fb763 100644
--- a/core/test/room-ticket-seat.test.js
+++ b/core/test/room-ticket-seat.test.js
@@ -243,7 +243,8 @@ test('#884: a stranger claims a room link with two of its Bots, both are seated,
   const mirror = guestRoomOf(b.rt)
   assert.ok(mirror, 'the joins projected the room on the guest side')
   assert.equal(Object.values(b.rt.state.rooms).filter(r => r.origin === 'inbound-share').length, 1, 'one room for both seats')
-  assert.deepEqual(mirror.participants.filter(p => p.leftSeq === undefined && p.kind === 'bot').map(p => p.id).sort(), ['chief-b', 'helper-b'])
+  // #904: the guest also lists the host's Bot that carried the join; before that it listed no host Bot at all.
+  assert.deepEqual(mirror.participants.filter(p => p.leftSeq === undefined && p.kind === 'bot').map(p => p.id).sort(), ['@chief.alice.home', '@writer.alice.home', 'chief-b', 'helper-b'])
   assert.equal(mirror.sharedFrom.remoteRoomId, 'war')
   assert.equal(mirror.sharedFrom.ticket, invite.ticket)
   assert.equal(mirror.sharedFrom.inviterName, 'Alice', 'the guest reads the owner, never the host’s own "You"')
diff --git a/docs/subsystems/core-client.md b/docs/subsystems/core-client.md
index 49408df4..e3a88a65 100644
--- a/docs/subsystems/core-client.md
+++ b/docs/subsystems/core-client.md
@@ -71,7 +71,7 @@ The overlay (`flybot-slots.js` `FlyBotApprovals`) is the fallback, not a second
 
 ### Face-to-face room lead
 
-- A local group's **Members · N** card (`group-settings.js`) ends with the plugin rows of slot `flybot.room.members` (`FlyBotRoomMembers` in `flybot-slots.js`), after the note on who leads the group (#892) and on the card's own row padding (`.bt-flybot-room-members`), never in a face or shared (`inbound-share`) room; the rows get `host`, the core endpoint call (also `__flybot__.host`), for `room-invite` / `room-invite-mint` / `room-invite-revoke` (#876, the social plugin's **Invite by link**). Covered by `core/test/room-members-slot.test.js`. Plugin copy that core's dictionary carries is translated through `__flybot__.t` (#892: Invite by link, the Join-or-create dialog), so a zh UI reads it in Chinese. A room a link opened is titled by its own name on the joining home (`roomTitle` in `remote-label.js`: sidebar, header, drawer, brand); "Shared room from …" stays as the sidebar row's hover and the **Shared** tag's title (#892).
+- A local group's **Members · N** card (`group-settings.js`) ends with the plugin rows of slot `flybot.room.members` (`FlyBotRoomMembers` in `flybot-slots.js`), after the note on who leads the group (#892) and on the card's own row padding (`.bt-flybot-room-members`), never in a face or shared (`inbound-share`) room; the rows get `host`, the core endpoint call (also `__flybot__.host`), for `room-invite` / `room-invite-mint` / `room-invite-revoke` (#876, the social plugin's **Invite by link**). Covered by `core/test/room-members-slot.test.js`. Plugin copy that core's dictionary carries is translated through `__flybot__.t` (#892: Invite by link, the Join-or-create dialog), so a zh UI reads it in Chinese. A room a link opened is titled by its own name on the joining home (`roomTitle` in `remote-label.js`: sidebar, header, drawer, brand); "Shared room from …" stays as the sidebar row's hover and the **Shared** tag's title (#892). In a room projected from another home the Members rows carry what that side could confirm (#904): a Bot learned from the host's roster reads **Unconfirmed** until this home holds its own fact about it, one with no Bot Social identity reads **Not connected**, and the remove **×** is not offered there — the host's membership is changed on the host's side.
 - The face room's details (`FaceMembers` in `details-drawer.js`) open with `FaceLead` (`group-settings.js`, #476): the current lead as `Bot (person)`, *Default* until the creator picked one. Only when `room.face.lead.canPick` (this home made the room and Bot Social stores a lead) does it show **Change**, a **Make lead** button per Bot of every home and **Use the default lead**; each calls `social/face-lead`. Everyone else sees it read-only. `FacePersonRow` marks the lead's Bot with a *Lead* tag (`isLeadSeat`, by handle). Never a chat command.
 
 ### Room avatars in face-to-face chats
diff --git a/docs/subsystems/core-host.md b/docs/subsystems/core-host.md
index c449d702..da34a378 100644
--- a/docs/subsystems/core-host.md
+++ b/docs/subsystems/core-host.md
@@ -149,7 +149,7 @@ Work a member hands a Bot with `message_bot` from its group Session runs in a hi
 
 ### Inbound shared rooms
 
-- Bot Social conversations are 1:1; it does not list a FlyBot group. When a room gains a granted remote Bot (create-room, addParticipants, or 新建群聊 picking a friend's chat), the host fans out a `FLYBOT-ROOM-SHARE` envelope (`src/shared/room-share.js`) through `flybotSend` (`via: 'room-share'` for join/leave, `via: 'room'` for lines, `meta.roomId` set) so the Bot's owner's FlyBot can project it immediately — including a room with no chat lines yet. Receive is `rt.applyInboundRoomShare` (`origin: 'inbound-share'`, `recordInboundSharedRoom`), labelled **Shared room from \<inviter\>** with the room name stored. The envelope names the person who invited the Bot (#848): a human participant in the room when there is one, else the owner-level `ownerName` / `home` the social plugin keeps on that Bot's member record (read from `whoami`), so a group made from the sidebar no longer says `a friend`; a human participant whose name is this home's own label `You` (an owner with no name yet) is skipped for that owner-level name, so the far side never reads itself as the inviter (#883); a room projected in from an inbound share forwards its own `sharedFrom` inviter instead of this home's owner, so re-sharing never renames the person who invited it. A leave envelope, hide, or grant revoke marks it left/hidden. A projection is **named** from the envelope and **matched** by the transport (#873, #909): `applyInboundRoomShare` still shows `data.inviterName` (so a room carried here by a Chief's Bot reads after the person who invited it), but which room a share may touch is decided by `event.fromHome` / `event.fromHandle` — a share naming a room of mine while arriving from a home that room does not belong to is refused `not-inviter`, and the recorded `sharedFrom` identity only ever follows the transport, so an envelope can be displayed but never re-write whose room it is. Only `op: 'join` projects a room: a `line` envelope for an unknown remote room is refused `unknown-room` instead of opening one named by its own payload. A line keeps its own `who`, or the sender when it names nobody, never the inviter; its `authorId` follows the payload only when the handle traces to the transport sender, a remote seat of that room, or its inviter — otherwise the line is shown as the Bot that delivered it with `unverified: true`, and it is still kept so a forged claim cannot silence a message. `reach()` allows a local member to message a remote that already sits in that room when `roomId` is on the send. Still not team mode.
+- Bot Social conversations are 1:1; it does not list a FlyBot group. When a room gains a granted remote Bot (create-room, addParticipants, or 新建群聊 picking a friend's chat), the host fans out a `FLYBOT-ROOM-SHARE` envelope (`src/shared/room-share.js`) through `flybotSend` (`via: 'room-share'` for join/leave, `via: 'room'` for lines, `meta.roomId` set) so the Bot's owner's FlyBot can project it immediately — including a room with no chat lines yet. Receive is `rt.applyInboundRoomShare` (`origin: 'inbound-share'`, `recordInboundSharedRoom`), labelled **Shared room from \<inviter\>** with the room name stored. The envelope names the person who invited the Bot (#848): a human participant in the room when there is one, else the owner-level `ownerName` / `home` the social plugin keeps on that Bot's member record (read from `whoami`), so a group made from the sidebar no longer says `a friend`; a human participant whose name is this home's own label `You` (an owner with no name yet) is skipped for that owner-level name, so the far side never reads itself as the inviter (#883); a room projected in from an inbound share forwards its own `sharedFrom` inviter instead of this home's owner, so re-sharing never renames the person who invited it. A leave envelope, hide, or grant revoke marks it left/hidden. A projection is **named** from the envelope and **matched** by the transport (#873, #909): `applyInboundRoomShare` still shows `data.inviterName` (so a room carried here by a Chief's Bot reads after the person who invited it), but which room a share may touch is decided by `event.fromHome` / `event.fromHandle` — a share naming a room of mine while arriving from a home that room does not belong to is refused `not-inviter`, and the recorded `sharedFrom` identity only ever follows the transport, so an envelope can be displayed but never re-write whose room it is. Only `op: 'join` projects a room: a `line` envelope for an unknown remote room is refused `unknown-room` instead of opening one named by its own payload. A line keeps its own `who`, or the sender when it names nobody, never the inviter; its `authorId` follows the payload only when the handle traces to the transport sender, a remote seat of that room, or its inviter — otherwise the line is shown as the Bot that delivered it with `unverified: true`, and it is still kept so a forged claim cannot silence a message. `reach()` allows a local member to message a remote that already sits in that room when `roomId` is on the send. Still not team mode. #904: the projection now records the host's side too. `recordInboundSharedRoom` keeps the guest's own Bot **and** one remote participant for the Bot that carried the join (`draft.inviterHandle`, with `admittedBy: 'ticket'` / `roomOnly` when a link seated it) — `invitedHandle` on this side names one of the guest's own Bots, so it is never recorded as a remote, and the friend path keeps its one remote. The rest of the host's room rides the `join` as `roster` and `notice`: `notifyRoomShare` sends `{ handle, home, name, ownerName }` for every Bot of this home in the room, and `{ name, ownerName, connected: false }` for one with no Bot Social identity; nothing of another guest's home is published, and the roster is re-sent whenever the host adds or removes a Bot of its own. `applyInboundRoomShare` reads a roster only when the envelope names this mirror's room (`data.roomId` = `sharedFrom.remoteRoomId`) and comes from its bound inviter, and merges it into the participants: one remote participant per entry (`fromRoster`, `roomOnly`), keyed by `(home, handle)` so two same-named Bots of different homes stay distinct, `verified` only for the seat or a published friend Bot, an unverified entry displayed but never addressed, an identity-less one shown as not connected. A roster is the whole list, so a `join` that drops an entry marks it left (soft leave: the entry stays with `leftSeq`, history still resolves) and a re-sent `join` clears the mark; an empty `roster: []` clears the list, while a `join` without the field changes nothing. The notice is replaced by the next `join` that carries one; an explicit empty string clears it and a missing field leaves it.
 - A Bot named in a shared room answers in that room (#825). `fanoutRoomLine` (`src/host/room-membership.js`) puts the handles a line calls in the envelope's `calls` (resolved where the room's mentions are resolved, so a fenced or quoted `@name` is literal text), plus its `hop`: a person's line is hop 0 and a Bot's answer is one hop on. The receiving `applyInboundRoomShare` keeps only the calls that name this room's own Bot (`localCalls`), opens **one** turn for each through `rt.startInboundTurn` (`groups.js`: `participant.open` + `participant.runTurn` + `appendRoom`), and skips it when the line's hop has reached the room's `maxHops` (kept on the room, `DEFAULT_MAX_HOPS` 3) or when the same remote line was already answered — the last 200 keys `remoteRoomId:seq:botId` live in `room.answered`. That turn's answer is an ordinary room line, so `fanoutRoomLine` sends it back to the inviter as an `op: 'line'` envelope under the *inviter's* `roomId`, one hop on; an answer its owner's approval holds or refuses still shows as one `notice` line in the room instead of silence. Remote text stays inside the `fencedUntrusted` fence.
 
 ### A local room's invite link (#852)
diff --git a/patches/ds-bot/0001-core-fixes.patch b/patches/ds-bot/0001-core-fixes.patch
index f9c824b6..ac60307e 100644
--- a/patches/ds-bot/0001-core-fixes.patch
+++ b/patches/ds-bot/0001-core-fixes.patch
@@ -518,7 +518,7 @@ diff --git a/src/client/i18n.js b/src/client/i18n.js
    Add: '添加',
    Close: '关闭',
    Copy: '复制',
-@@ -41,22 +41,67 @@ const ZH = {
+@@ -41,22 +41,69 @@ const ZH = {
    ' and ': '、',
    and: '和',
    '{count} members': '{count} 位成员',
@@ -578,6 +578,8 @@ diff --git a/src/client/i18n.js b/src/client/i18n.js
 +  Retry: '重试',
 +  Approve: '批准',
 +  "Friend's Bot": '好友的 Bot',
++  'Unconfirmed': '未确认',
++  'Not connected': '未接入',
 +  'Expand': '展开',
 +  'Collapse': '收起',
    'Setting up your Main Bot…': '正在设置你的主 Bot…',
diff --git a/patches/ds-bot/0008-client-bundle.patch b/patches/ds-bot/0008-client-bundle.patch
index a1205893..3dbac4fe 100644
--- a/patches/ds-bot/0008-client-bundle.patch
+++ b/patches/ds-bot/0008-client-bundle.patch
@@ -74,7 +74,7 @@ diff --git a/client.js b/client.js
    Add: "添加",
    Close: "关闭",
    Copy: "复制",
-@@ -78,21 +78,66 @@ var ZH = {
+@@ -78,21 +78,68 @@ var ZH = {
    " and ": "、",
    and: "和",
    "{count} members": "{count} 位成员",
@@ -133,6 +133,8 @@ diff --git a/client.js b/client.js
 +  Retry: "重试",
 +  Approve: "批准",
 +  "Friend's Bot": "好友的 Bot",
++  "Unconfirmed": "未确认",
++  "Not connected": "未接入",
 +  "Expand": "展开",
 +  "Collapse": "收起",
    "Setting up your Main Bot…": "正在设置你的主 Bot…",
@@ -10692,7 +10694,7 @@ diff --git a/client.js b/client.js
            key: id,
            type: "button",
            "aria-pressed": mode === id,
-@@ -8999,86 +8999,139 @@ function GroupSettingsForm({ room: room2, roster, actions, run, onDeleted }) {
+@@ -8999,86 +8999,142 @@ function GroupSettingsForm({ room: room2, roster, actions, run, onDeleted }) {
              if (mode !== id) void update({ mode: id });
            }
          }, t(label)))),
@@ -10770,9 +10772,12 @@ diff --git a/client.js b/client.js
 +          { className: "bt-gs-who" },
 +          (0, import_react30.createElement)(BotAvatar, { bot: lookBotForRemote(person, roster), size: 26, badge: false, live: false }),
 +          (0, import_react30.createElement)("span", { className: "bt-row-title", title: person.handle || void 0 }, person.label || remoteBotTitle(person)),
-+          room2.origin === "face-to-face" ? null : (0, import_react30.createElement)("span", { className: "bt-tag" }, t("Friend's Bot"))
++          // #904: a host's roster entry is not a friend's Bot, and one this home cannot confirm is
++          // labelled as such; a Bot with no Bot Social identity can never be written to at all.
++          room2.origin === "face-to-face" ? null : (0, import_react30.createElement)("span", { className: "bt-tag" }, person.unconnected ? t("Not connected") : room2.origin === "inbound-share" && person.verified === false ? t("Unconfirmed") : t("Friend's Bot"))
 +        ),
-+        room2.origin === "face-to-face" || members.length + remotes.length <= 2 ? null : (0, import_react30.createElement)("button", { type: "button", className: "bt-x", "aria-label": t("Remove {name} from the group", { name: remoteBotTitle(person) }), title: t("Remove from group"), onClick: () => update({ removeParticipants: [{ kind: "bot", id: person.handle || person.id, remote: true }] }) }, "×")
++        // A guest's mirror is not theirs to edit: the host's membership is changed on the host side.
++        room2.origin === "face-to-face" || room2.origin === "inbound-share" || members.length + remotes.length <= 2 ? null : (0, import_react30.createElement)("button", { type: "button", className: "bt-x", "aria-label": t("Remove {name} from the group", { name: remoteBotTitle(person) }), title: t("Remove from group"), onClick: () => update({ removeParticipants: [{ kind: "bot", id: person.handle || person.id, remote: true }] }) }, "×")
 +      )),
 +      room2.origin === "face-to-face" ? null : adding ? [
 +        ...outsidePeople.map((person) => (0, import_react30.createElement)(
diff --git a/patches/ds-bot/0012-room-membership.patch b/patches/ds-bot/0012-room-membership.patch
index 299e5b19..ca07777f 100644
--- a/patches/ds-bot/0012-room-membership.patch
+++ b/patches/ds-bot/0012-room-membership.patch
@@ -403,7 +403,7 @@ diff --git a/src/client/group-settings.js b/src/client/group-settings.js
    const admin = roster.byId[room.admin]
    const mode = shownMode(room, roster)
    const modeHint = ROOM_MODES.find(([id]) => id === mode)?.[2] ?? ''
-@@ -65,37 +65,67 @@ export function GroupSettingsForm({ room, roster, actions, run, onDeleted }) {
+@@ -65,37 +65,73 @@ export function GroupSettingsForm({ room, roster, actions, run, onDeleted }) {
        h('div', { className: 'bt-set-row bt-bs-row' },
          h('span', { className: 'bt-set-copy' }, h('span', { className: 'bt-bs-label' }, t('Folder'))),
          h(FolderMenu, { value: room.workDir, group: true, actions, run, onPick: workDir => update({ workDir }) }))),
@@ -439,8 +439,14 @@ diff --git a/src/client/group-settings.js b/src/client/group-settings.js
 +        h('span', { className: 'bt-gs-who' },
 +          h(BotAvatar, { bot: lookBotForRemote(person, roster), size: 26, badge: false, live: false }),
 +          h('span', { className: 'bt-row-title', title: person.handle || undefined }, person.label || remoteBotTitle(person)),
-+          room.origin === 'face-to-face' ? null : h('span', { className: 'bt-tag' }, t('Friend\'s Bot'))),
-+        room.origin === 'face-to-face' || members.length + remotes.length <= 2
++          // #904: a host's roster entry is not a friend's Bot, and one this home cannot confirm is
++          // labelled as such; a Bot with no Bot Social identity can never be written to at all.
++          room.origin === 'face-to-face' ? null
++            : h('span', { className: 'bt-tag' }, person.unconnected ? t('Not connected')
++              : room.origin === 'inbound-share' && person.verified === false ? t('Unconfirmed')
++                : t('Friend\'s Bot'))),
++        // A guest's mirror is not theirs to edit: the host's membership is changed on the host side.
++        room.origin === 'face-to-face' || room.origin === 'inbound-share' || members.length + remotes.length <= 2
 +          ? null
 +          : h('button', { type: 'button', className: 'bt-x', 'aria-label': t('Remove {name} from the group', { name: remoteBotTitle(person) }), title: t('Remove from group'), onClick: () => update({ removeParticipants: [{ kind: 'bot', id: person.handle || person.id, remote: true }] }) }, '×'))),
 +      room.origin === 'face-to-face' ? null : adding
diff --git a/patches/ds-bot/files/src/host/room-membership.js b/patches/ds-bot/files/src/host/room-membership.js
index ffda33ad..e7cd2d7f 100644
--- a/patches/ds-bot/files/src/host/room-membership.js
+++ b/patches/ds-bot/files/src/host/room-membership.js
@@ -691,6 +691,7 @@ export function install(rt) {
       syncMembers(room)
       await rt.save()
       if (record?.remote && record.handle) void rt.notifyRoomShare?.(room, { op: 'join', handle: record.handle })
+      else if (record?.kind === 'bot' && !record.remote) reshareRoster(room)
       return room
     })
   }
@@ -708,7 +709,9 @@ export function install(rt) {
         throw forbidden('Only a room admin can remove participants')
       }
       const live = currentParticipants(room)
-      const botsLeft = live.filter(p => p.kind === 'bot' && p.id !== me.id && p.handle !== me.handle)
+      // A local Bot has no handle: comparing handles alone dropped every local Bot from the count, so
+      // removing one always tripped the two-Bot rule. Compare by handle only when the entry has one.
+      const botsLeft = live.filter(p => p.kind === 'bot' && p.id !== me.id && (!me.handle || p.handle !== me.handle))
       const ownerLeave = actor && (
         (kind === 'human' && me.id === actor.memberId)
         || (kind === 'bot' && (state.bots?.[me.id]?.ownerId === actor.memberId || me.ownerId === actor.memberId || room.sharedFrom?.ownerId === actor.memberId))
@@ -735,6 +738,8 @@ export function install(rt) {
           .catch(error => rt.warn?.('ds-bot: a seat\'s leave was not settled: %s', error))
       } else if (kind === 'bot' && room.origin === 'inbound-share' && room.sharedFrom?.ticket) {
         void leaveTicketRoom(room, me).catch(error => rt.warn?.('ds-bot: leaving %s was not sent: %s', room.name, error))
+      } else if (kind === 'bot' && !me.remote) {
+        reshareRoster(room)
       }
       return room
     })
@@ -953,6 +958,172 @@ export function install(rt) {
     }
   }
 
+  // #904: a guest's copy learns this home's membership only from a fresh roster. A local add or remove
+  // therefore has to send one; without this the guest list never changes and a removed Bot keeps writing.
+  function reshareRoster(room) {
+    if (!room || room.origin === 'inbound-share' || isFaceRoom(room)) return
+    if (!(room.participants ?? []).some(p => p.remote)) return
+    void Promise.resolve(rt.notifyRoomShare?.(room, { op: 'join' }))
+      .catch(error => rt.warn?.('ds-bot: a membership change was not shared: %s', error))
+  }
+
+  // #904: the Bots this home keeps in the room, for the guests' copies of it. Only this home's own Bots:
+  // another guest's Bot is not this home's to publish. A Bot with no Bot Social identity rides along as
+  // `connected: false` so the guest can show it as not connected instead of leaving it out entirely.
+  function roomRoster(room) {
+    const out = []
+    for (const p of currentParticipants(room)) {
+      if (p.kind !== 'bot' || p.remote) continue
+      const bot = state.bots?.[p.id]
+      const member = bot?.fields?.social?.member
+      const handle = typeof member?.handle === 'string' && /^@[A-Za-z0-9._-]{1,120}$/.test(member.handle) ? member.handle : undefined
+      const name = bot?.name || p.displayName || p.id
+      const ownerName = ownerNameSafe(p) || cleanPeerName(member?.ownerName, '')
+      // #904: (home, handle) is the identity a guest keys on; a handle alone is unique only inside a home.
+      const home = typeof member?.home === 'string' && /^@[A-Za-z0-9._-]{1,120}$/.test(member.home) ? member.home : ''
+      const homeField = home ? { home } : {}
+      out.push(handle ? { handle, name, ...homeField, ...(ownerName ? { ownerName } : {}) } : { name, ...homeField, ...(ownerName ? { ownerName } : {}) })
+    }
+    return out
+  }
+
+  // #904: a roster is text a stranger wrote. It is read only for the room this mirror is bound to and
+  // only from that room's own inviter; anything else is dropped whole. Every entry it names stays
+  // unverified unless this home already holds a fact about that handle (the seat that carried the join,
+  // or a published friend Bot) — an unverified entry is displayed, never addressed.
+  function rosterOf(data, room, event) {
+    if (!Array.isArray(data?.roster)) return undefined
+    const bound = room?.sharedFrom ?? {}
+    const same = (a, b) => {
+      const left = String(a ?? '').trim().toLowerCase()
+      return left !== '' && left === String(b ?? '').trim().toLowerCase()
+    }
+    if (!same(data.roomId, bound.remoteRoomId)) return undefined
+    if (bound.inviterHome && bound.inviterHandle) {
+      if (!same(event?.fromHome, bound.inviterHome) || !same(event?.fromHandle, bound.inviterHandle)) return undefined
+    } else if (bound.inviterHome ? !same(event?.fromHome, bound.inviterHome) : !same(event?.fromHandle, bound.inviterHandle)) return undefined
+    const seat = String(bound.invitedHandle ?? '')
+    const out = []
+    for (const entry of data.roster.slice(0, 32)) {
+      const name = cleanPeerName(entry?.name, '')
+      const ownerName = cleanPeerName(entry?.ownerName, '')
+      const handle = String(entry?.handle ?? '').trim()
+      // The entry's home is identity, not trust: verification stays on the transport's home.
+      const entryHome = String(entry?.home ?? '').trim()
+      const ownerHome = /^@[A-Za-z0-9._-]{1,120}$/.test(entryHome) ? entryHome : bound.inviterHome
+      if (!handle) {
+        if (name) out.push({ name, ownerName, ownerHome, connected: false })
+        continue
+      }
+      if (!/^@[A-Za-z0-9._-]{1,120}$/.test(handle)) continue
+      out.push({
+        handle,
+        ownerHome,
+        name: name || handle,
+        ownerName,
+        verified: (handle === seat && same(ownerHome, bound.inviterHome)) || Boolean(publishedRemoteOf(state, handle)),
+      })
+    }
+    return out
+  }
+
+  // #904: the host room's notice rides the join like the roster (the guest's group settings were empty).
+  // It is stranger-written text too, so it is read only for the room this mirror is bound to and only
+  // from that room's own inviter; an empty value is not encoded, so it never wipes a notice.
+  function noticeOf(data, room, event) {
+    if (data?.op !== 'join' || typeof data.notice !== 'string') return undefined
+    const text = data.notice.replace(/[\u0000-\u001f\u007f-\u009f]/g, ' ').trim().slice(0, 2000)
+    const bound = room?.sharedFrom ?? {}
+    const same = (a, b) => {
+      const left = String(a ?? '').trim().toLowerCase()
+      return left !== '' && left === String(b ?? '').trim().toLowerCase()
+    }
+    if (bound.remoteRoomId && !same(data.roomId, bound.remoteRoomId)) return undefined
+    if (bound.inviterHome && !same(event?.fromHome, bound.inviterHome)) return undefined
+    if (bound.inviterHandle && !same(event?.fromHandle, bound.inviterHandle)) return undefined
+    return text
+  }
+
+  // #904: one remote participant per roster entry. A roster is the whole list, so an entry it drops is a
+  // Bot the host no longer keeps here: it leaves this mirror's list, and nothing of it stays addressable.
+  function applyRoster(room, entries) {
+    if (!Array.isArray(entries)) return false
+    let changed = false
+    const seen = new Set()
+    const seat = String(room.sharedFrom?.invitedHandle ?? '')
+    const boundHome = room.sharedFrom?.inviterHome
+    const sameHome = (a, b) => {
+      const left = String(a ?? '').trim().toLowerCase()
+      return left !== '' && left === String(b ?? '').trim().toLowerCase()
+    }
+    const at = Date.now()
+    for (const entry of entries) {
+      const key = entry.handle || `not-connected:${entry.name.toLowerCase()}`
+      const ownerHome = entry.ownerHome || boundHome
+      seen.add(key)
+      // #904: one entry per (home, handle), so a same-named Bot of another home is a different Bot.
+      const found = (room.participants ?? []).find(p => p.remote && (p.handle === key || p.id === key)
+        && (!entry.handle || sameHome(p.ownerHome ?? boundHome, ownerHome)))
+      if (found) {
+        if (found.leftSeq !== undefined) {
+          delete found.leftSeq
+          delete found.leftAt
+          changed = true
+        }
+        if (entry.name && found.displayName !== entry.name) {
+          found.displayName = entry.name
+          changed = true
+        }
+        if (entry.ownerName && found.ownerName !== entry.ownerName) {
+          found.ownerName = entry.ownerName
+          changed = true
+        }
+        if (entry.handle && entry.handle === seat && found.verified !== true) {
+          found.verified = true
+          changed = true
+        }
+        continue
+      }
+      room.participants = [...(room.participants ?? []), entry.handle ? {
+        kind: 'bot',
+        remote: true,
+        id: entry.handle,
+        handle: entry.handle,
+        ownerHome,
+        ownerName: entry.ownerName,
+        displayName: entry.name,
+        role: 'member',
+        fromRoster: true,
+        verified: entry.verified === true,
+        roomOnly: true,
+        joinedSeq: room.seq ?? 0,
+        joinedAt: at,
+      } : {
+        kind: 'bot',
+        remote: true,
+        id: key,
+        unconnected: true,
+        ownerName: entry.ownerName,
+        displayName: entry.name,
+        role: 'member',
+        fromRoster: true,
+        verified: false,
+        roomOnly: true,
+        joinedSeq: room.seq ?? 0,
+        joinedAt: at,
+      }]
+      changed = true
+    }
+    for (const p of room.participants ?? []) {
+      if (!p.fromRoster || p.leftSeq !== undefined) continue
+      if (seen.has(p.handle || p.id)) continue
+      p.leftSeq = room.seq ?? 0
+      p.leftAt = at
+      changed = true
+    }
+    return changed
+  }
+
   // Membership notice: the add/remove click is the owner's consent, so this does not wait
   // for a chat line. Bot Social is 1:1; the envelope is the group record the other FlyBot sees.
   rt.notifyRoomShare = async function notifyRoomShare(room, { op = 'join', handle } = {}) {
@@ -973,6 +1144,7 @@ export function install(rt) {
           invitedHandle: remote.handle,
           seq: room.seq ?? 0,
           ticket: remote.ticket,
+          ...(op === 'join' ? { roster: roomRoster(room), notice: room.notice || '' } : {}),
           ...seat.from,
         }, 'room-share', seat.botId, room.id)
         continue
@@ -984,6 +1156,7 @@ export function install(rt) {
         name: room.name,
         invitedHandle: remote.handle,
         seq: room.seq ?? 0,
+        ...(op === 'join' ? { roster: roomRoster(room), notice: room.notice || '' } : {}),
         ...from,
       }, 'room-share')
     }
@@ -1477,6 +1650,9 @@ export function install(rt) {
     const who = cleanPeerName(data.who, remoteBotTitle(seat))
     const hop = Number.isFinite(Number(data.hop)) ? Math.max(0, Math.floor(Number(data.hop))) : 0
     const human = data.authorKind !== 'bot'
+    // #904: this path never reads the envelope's `authorId`: `ownSeatOf` matched the seat by the
+    // transport's own `fromHandle`, so `seat.handle` is already the Bot that wrote the line, while a
+    // claim inside the envelope is only the guest's word. A guest cannot speak as another Bot here.
     const posted = append(room, rt.authoredRoomLine(room, {
       who,
       text: data.text || '',
@@ -1767,8 +1943,17 @@ export function install(rt) {
     const sender = String(event.fromHandle ?? '')
     if (!claim) return sender ? { authorId: sender, authorKind: 'bot' } : { authorId: undefined, authorKind: 'human' }
     if (!claim.startsWith('@')) return { authorId: claim, authorKind: kind }
+    // #904: a remote seat stands for the handle only when this home verified it and it belongs to the
+    // home the transport names: two homes may carry the same handle, and an unverified roster entry is a
+    // display fact, never a signature.
+    const sameHome = (left, right) => {
+      const a = String(left ?? '').trim().toLowerCase()
+      return a !== '' && a === String(right ?? '').trim().toLowerCase()
+    }
     const traced = claim === sender
-      || currentParticipants(room).some(p => p.remote === true && (p.handle === claim || p.id === claim))
+      || currentParticipants(room).some(p => p.remote === true && p.leftSeq === undefined
+        && p.verified === true && (p.handle === claim || p.id === claim)
+        && sameHome(p.ownerHome ?? room.sharedFrom?.inviterHome, event.fromHome))
       || room.sharedFrom?.inviterHandle === claim
     return traced ? { authorId: claim, authorKind: kind } : { authorId: sender || claim, authorKind: 'bot', unverified: true }
   }
@@ -1894,6 +2079,8 @@ export function install(rt) {
         remoteRoomId: data.roomId,
         joinedSeq: data.seq,
         ...(ticket && data.op === 'join' ? { ticket } : {}),
+        ...(data.op === 'join' ? { roster: rosterOf(data, { sharedFrom: { remoteRoomId: data.roomId, inviterHome: event.fromHome, inviterHandle: event.fromHandle, invitedHandle: data.invitedHandle } }, event) } : {}),
+        ...(typeof noticeOf(data, undefined, event) === 'string' ? { notice: noticeOf(data, undefined, event) } : {}),
       }, actor || (ownerId ? { memberId: ownerId } : undefined))
     } else {
       delete room.hidden
@@ -1914,11 +2101,15 @@ export function install(rt) {
         }]
         room.sharedFrom = { ...room.sharedFrom, ticket }
       }
-      for (const p of room.participants ?? []) {
-        if (seatedHere && p.id !== localBotId) continue
-        if (p.leftSeq !== undefined) {
-          delete p.leftSeq
-          delete p.leftAt
+      // #904: only a join brings anyone back. A line on an existing mirror must not clear the soft leaves
+      // a roster just set, or a plain message would quietly undo a removal.
+      if (data.op === 'join') {
+        for (const p of room.participants ?? []) {
+          if (seatedHere && p.id !== localBotId) continue
+          if (p.leftSeq !== undefined) {
+            delete p.leftSeq
+            delete p.leftAt
+          }
         }
       }
       if (data.name) room.name = cleanPeerName(data.name, room.name)
@@ -1932,6 +2123,11 @@ export function install(rt) {
         invitedHandle: data.invitedHandle || room.sharedFrom?.invitedHandle,
         remoteRoomId: data.roomId,
       }
+      // #904: the host re-sends the whole roster when its membership changes, so this list is the
+      // current one; a Bot it no longer names leaves this mirror.
+      applyRoster(room, data.op === 'join' ? rosterOf(data, room, event) : undefined)
+      const notice = noticeOf(data, room, event)
+      if (typeof notice === 'string') room.notice = notice
       syncMembers(room)
     }
     let called = []
@@ -1980,6 +2176,10 @@ export function install(rt) {
     if (!ownerId) throw invalid('Sign in first')
     const handle = draft.invitedHandle || draft.handle
     const localBotId = draft.localBotId && state.bots?.[draft.localBotId] ? draft.localBotId : undefined
+    // #904: `invitedHandle` on this side names one of my own Bots (the share addressed it), so the
+    // host's Bot to record is the one that carried the join. A handle this home owns is never a remote.
+    const seatHandle = typeof draft.inviterHandle === 'string' && draft.inviterHandle.startsWith('@') ? draft.inviterHandle : undefined
+    const mineHandles = new Set(Object.values(state.bots ?? {}).map(bot => bot?.fields?.social?.member?.handle).filter(own => typeof own === 'string'))
     const at = Date.now()
     const inviterName = cleanPeerName(draft.inviterName, 'a friend')
     const title = cleanPeerName(draft.name, sharedRoomTitle(inviterName))
@@ -2026,7 +2226,35 @@ export function install(rt) {
           joinedAt: draft.invitedAt ?? at,
           invitedByName: inviterName,
           invitedAt: draft.invitedAt ?? at,
-        }] : handle ? [{
+        }] : []),
+        // #904: the host's seat Bot is a participant of its own, not the alternative to mine. A guest
+        // always brings a Bot (`localBotId`), so the old either/or dropped the host's side whole — the
+        // reported "they cannot see my Bots". The seat is the Bot that carried the join (the inviter),
+        // never `invitedHandle`: on this side that is one of my own Bots. It keeps the shape a ticket
+        // seat has here (#884).
+        ...(seatHandle && !mineHandles.has(seatHandle) ? [{
+          kind: 'bot',
+          remote: true,
+          id: seatHandle,
+          handle: seatHandle,
+          ownerHome: draft.inviterHome,
+          ownerName: inviterName,
+          displayName: cleanPeerName(draft.inviterBotName, seatHandle),
+          role: 'member',
+          ...(typeof draft.ticket === 'string' && draft.ticket ? { admittedBy: 'ticket', ticket: draft.ticket } : {}),
+          verified: true,
+          roomOnly: true,
+          joinedSeq: draft.joinedSeq ?? 0,
+          joinedAt: draft.invitedAt ?? at,
+          invitedByName: inviterName,
+          invitedAt: draft.invitedAt ?? at,
+          ownerId,
+        }] : []),
+        // The friend path's remote Bot: a share that names a Bot of another home and brought none of
+        // mine. The either/or this replaces kept one of the two, and a share may legitimately name both.
+        // When this home brought a Bot, `invitedHandle` names one of my own Bots (the share addressed it):
+        // recording it as remote would list my own Bot twice, once under each name.
+        ...(handle && handle !== seatHandle && !mineHandles.has(handle) && !(localBotId && handle === draft.invitedHandle) ? [{
           kind: 'bot',
           remote: true,
           id: handle,
@@ -2035,6 +2263,8 @@ export function install(rt) {
           ownerName: inviterName,
           displayName: cleanPeerName(draft.botName, handle),
           role: 'member',
+          verified: true,
+          roomOnly: true,
           joinedSeq: draft.joinedSeq ?? 0,
           joinedAt: draft.invitedAt ?? at,
           invitedByName: inviterName,
@@ -2044,6 +2274,10 @@ export function install(rt) {
       ],
     }
     state.rooms[id] = room
+    // #904: the notice the join carried (gated by the caller) is the room's own notice.
+    if (typeof draft.notice === 'string') room.notice = draft.notice
+    // #904: the roster the join carried, merged on top of the two above (the seat is already there).
+    if (applyRoster(room, draft.roster)) syncMembers(room)
     await rt.save?.()
     return room
   }
diff --git a/patches/ds-bot/files/src/shared/room-share.js b/patches/ds-bot/files/src/shared/room-share.js
index 0edf88c4..818bde3f 100644
--- a/patches/ds-bot/files/src/shared/room-share.js
+++ b/patches/ds-bot/files/src/shared/room-share.js
@@ -14,6 +14,27 @@ function clip(value, max = 60) {
   return String(value ?? '').replace(/[\u0000-\u001f\u007f-\u009f]/g, ' ').trim().slice(0, max)
 }
 
+// #904: a room's roster entry. A Bot inside a real room is a handful, not a crowd; the cap keeps one
+// envelope from turning into a member dump a guest has to render.
+export const ROSTER_MAX = 32
+// The group notice's own limit in the room editor (core/src/client/group-settings.js).
+export const NOTICE_MAX = 2000
+
+// #904: a handle is unique only inside its home, so an entry carries the home it belongs to: two homes
+// can keep Bots with the same local name, and a guest has to tell them apart when it attributes a line.
+// The receiving side verifies against the transport's home; this field is for identity, not for trust.
+function rosterEntry(entry = {}) {
+  const handle = clip(entry.handle, 120)
+  const home = clip(entry.home, 120)
+  const out = { name: clip(entry.name) }
+  if (handle) out.handle = handle
+  if (/^@[A-Za-z0-9._-]{1,120}$/.test(home)) out.home = home
+  const ownerName = clip(entry.ownerName)
+  if (ownerName) out.ownerName = ownerName
+  if (!handle) out.connected = false
+  return out
+}
+
 export function encodeRoomShare(payload = {}) {
   const body = {
     v: 1,
@@ -49,6 +70,18 @@ export function encodeRoomShare(payload = {}) {
   if (Array.isArray(payload.calls) && payload.calls.length > 0) {
     body.calls = payload.calls.map(handle => clip(handle, 120)).filter(Boolean).slice(0, 24)
   }
+  // #904: the host room's Bots ride the membership notice so the guest's mirror can list them. It is
+  // display data only — the guest still takes reachability from Bot Social, so a roster can never hand
+  // out a send path. `connected: false` is a Bot with no Bot Social identity: shown, never addressed.
+  // #904: an explicit roster is encoded even when empty — empty means the host keeps none of its Bots in
+  // the room any more, while an absent field means "change nothing" (an older host).
+  if (body.op === 'join' && Array.isArray(payload.roster)) {
+    body.roster = payload.roster.slice(0, ROSTER_MAX).map(rosterEntry).filter(entry => entry.connected === false || entry.handle)
+  }
+  // #904: the host room's notice rides the same join envelope, so the guest's group settings are not
+  // empty. It is text the room displays, never authority. A present notice is encoded even when empty:
+  // empty means the host cleared it, while an absent field means "change nothing" (an older host).
+  if (body.op === 'join' && typeof payload.notice === 'string') body.notice = clip(payload.notice, NOTICE_MAX)
   return `${ROOM_SHARE_MARK}\n${JSON.stringify(body)}`
 }
 
diff --git a/patches/ds-bot/files/test/remote-room.test.js b/patches/ds-bot/files/test/remote-room.test.js
index c39880f6..e58bf7a9 100644
--- a/patches/ds-bot/files/test/remote-room.test.js
+++ b/patches/ds-bot/files/test/remote-room.test.js
@@ -1575,3 +1575,390 @@ test('#909: a line is never shown under a handle the room cannot trace', async (
   assert.equal(own.authorId, '@chief.alice.home')
   assert.equal(own.unverified, undefined)
 })
+
+
+// #904: a guest who joins with a link always brings a Bot, and the participants list treated the local
+// Bot and the host's seat Bot as alternatives. The host's side was therefore dropped whole: the guest's
+// room listed themselves and their own Bot, nothing of the host's — the reported "they cannot see my Bots".
+test('#904: a link join keeps the host\'s seat Bot beside the guest\'s own', async (t) => {
+  const { rt } = host(t, TEAM)
+  await rt.load()
+  const { bob } = await signAliceAndBob(rt)
+  const actorB = await rt.authenticate(bob.sessionToken)
+  const room = await rt.recordInboundSharedRoom({
+    id: 'from-alice',
+    name: 'War room',
+    inviterName: 'Alice',
+    inviterHome: '@alice.home',
+    inviterHandle: '@chief.alice.home',
+    invitedHandle: '@spec.b.bob.home',
+    localBotId: 'spec-b',
+    remoteRoomId: 'alice-war',
+    joinedSeq: 2,
+    ticket: 'AbCdEfGhIjKlMnOpQrStUv',
+  }, actorB)
+  const bots = room.participants.filter(p => p.kind === 'bot')
+  assert.deepEqual(bots.filter(p => !p.remote).map(p => p.id), ['spec-b'], 'the guest\'s own Bot stays')
+  const seat = bots.find(p => p.remote)
+  assert.ok(seat, 'the host\'s seat Bot is recorded too, not only the guest\'s Bot')
+  assert.equal(seat.handle, '@chief.alice.home', 'the Bot that carried the join, never the invited handle')
+  assert.equal(seat.admittedBy, 'ticket', 'the seat keeps the shape a ticket seat has')
+  assert.equal(seat.roomOnly, true, 'a seat is reachable inside the room it was admitted to, nowhere else')
+  assert.equal(seat.verified, true)
+  // The report's "Members · 2" is You + your own Bot, and the badge on it is the guest's own Bot: admin is
+  // `localBotId` alone, so a host Bot becoming a participant must not take the badge with it.
+  assert.equal(room.participants.length, 3, 'you, your own Bot, and the host seat: three')
+  assert.equal(room.admin, 'spec-b', 'the guest\'s own Bot stays the admin of its mirror')
+  assert.equal(seat.role, 'member', 'the host seat is a member, never the admin')
+  // The fix lands in `participants` only: `room.members` is what speaks, leads and renders, and a remote
+  // handle there would hand the guest a member of its own group.
+  assert.deepEqual(room.members, ['spec-b'], 'the room members stay local; a remote is never a member')
+})
+
+// #904: the join notice carries the host room's Bot roster, and the guest lists every Bot in it. What a
+// roster decides is who is displayed: an entry this home cannot confirm stays unverified and unreachable.
+test('#904: a join roster lists every host Bot, and a line keeps the Bot that wrote it', async (t) => {
+  const { rt } = host(t, TEAM)
+  await rt.load()
+  const { bob } = await signAliceAndBob(rt)
+  const actorB = await rt.authenticate(bob.sessionToken)
+  // A published friend Bot in the roster is a fact this home holds, so that entry is verified.
+  publish(rt, [{ ...CODER, handle: '@writer.a.home', name: 'Writer A', home: '@alice.home', homeName: 'Alice', owner: 'Alice' }])
+  const join = encodeRoomShare({
+    op: 'join', roomId: 'alice-war', name: 'War room', inviterName: 'Alice',
+    inviterHome: '@alice.home', inviterHandle: '@chief.alice.home', invitedHandle: '@chief.b.alice.home', seq: 4,
+    notice: 'Be nice to each other.',
+    roster: [
+      { handle: '@chief.a.home', home: '@alice.home', name: 'Chief A', ownerName: 'Alice' },
+      { handle: '@chief.b.alice.home', home: '@alice.home', name: 'Chief B', ownerName: 'Alice' },
+      { handle: '@writer.a.home', home: '@alice.home', name: 'Writer A', ownerName: 'Alice' },
+      { handle: '@ghost.alice.home', home: '@alice.home', name: 'Ghost', ownerName: 'Alice' },
+      { name: 'Offline Bot', ownerName: 'Alice' },
+    ],
+  })
+  assert.equal(parseRoomShare(join).roster.length, 5, 'the roster rides the existing envelope')
+  const first = await rt.applyInboundRoomShare({
+    fromHandle: '@chief.alice.home', fromHome: '@alice.home', fromName: 'Alice',
+    text: join, localBotId: 'spec-b',
+  }, actorB)
+  const room = first.room
+  assert.equal(room.notice, 'Be nice to each other.', 'the group notice rides the join, so the guest\'s settings are not empty')
+  const live = room.participants.filter(p => p.leftSeq === undefined)
+  const handles = live.filter(p => p.kind === 'bot' && p.remote).map(p => p.handle ?? p.id).sort()
+  assert.deepEqual(handles, [
+    '@chief.a.home', '@chief.alice.home', '@chief.b.alice.home', '@ghost.alice.home', '@writer.a.home', 'not-connected:offline bot',
+  ], 'every Bot the host named is listed, and the guest\'s own Bot is not the only one')
+  const seat = live.find(p => p.handle === '@chief.b.alice.home')
+  assert.equal(seat.verified, true, 'the seat that carried the join is this home\'s own fact')
+  assert.equal(live.find(p => p.handle === '@chief.a.home').ownerHome, '@alice.home', 'the roster entry carries the home its handle is unique in')
+  const named = live.find(p => p.handle === '@writer.a.home')
+  assert.equal(named.displayName, 'Writer A')
+  assert.equal(named.ownerName, 'Alice', 'the guest can tell whose Bot it is')
+  assert.equal(named.verified, true, 'a published friend Bot is this home\'s own fact')
+  const ghost = live.find(p => p.handle === '@ghost.alice.home')
+  assert.equal(ghost.verified, false, 'a name in a stranger\'s roster is not proof')
+  assert.equal(named.roomOnly, true, 'a roster never widens reach')
+  const offline = live.find(p => p.unconnected === true)
+  assert.equal(offline.displayName, 'Offline Bot')
+  assert.equal(offline.handle, undefined, 'a Bot with no identity has no handle to write to')
+  // The client reads these through presentRoom, which keeps the whole live list.
+  const shown = presentRoom(rt.state.rooms[room.id], actorB, rt.state)
+  assert.equal(shown.presentedParticipants.filter(p => p.remote).length, 6)
+
+  // A line keeps the Bot that wrote it — not the seat, not the inviter — when the roster holds it.
+  const line = encodeRoomShare({
+    op: 'line', roomId: 'alice-war', inviterName: 'Alice', inviterHome: '@alice.home',
+    inviterHandle: '@chief.b.alice.home', invitedHandle: '@chief.b.alice.home', seq: 5,
+    who: 'Writer A', authorKind: 'bot', authorId: '@writer.a.home', text: 'on it',
+  })
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: line, localBotId: 'spec-b' }, actorB)
+  const posted = room.log.filter(entry => String(entry.text).includes('on it')).at(-1)
+  assert.equal(posted.authorId, '@writer.a.home')
+  assert.equal(posted.botId, '@writer.a.home')
+
+  // A line that names a Bot this room never verified is said by the inviter, never by that Bot.
+  const forged = encodeRoomShare({
+    op: 'line', roomId: 'alice-war', inviterName: 'Alice', inviterHome: '@alice.home',
+    inviterHandle: '@chief.b.alice.home', invitedHandle: '@chief.b.alice.home', seq: 6,
+    who: 'Ghost', authorKind: 'bot', authorId: '@nobody.home', text: 'not me',
+  })
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: forged, localBotId: 'spec-b' }, actorB)
+  const forgedLine = room.log.filter(entry => String(entry.text).includes('not me')).at(-1)
+  assert.equal(forgedLine.authorId, '@chief.alice.home', 'an invented author never speaks as another Bot')
+
+  // A line that names an unverified roster entry is said by the inviter, never by that Bot.
+  const fromGhost = encodeRoomShare({
+    op: 'line', roomId: 'alice-war', inviterName: 'Alice', inviterHome: '@alice.home',
+    inviterHandle: '@chief.b.alice.home', invitedHandle: '@chief.b.alice.home', seq: 7,
+    who: 'Ghost', authorKind: 'bot', authorId: '@ghost.alice.home', text: 'not verified',
+  })
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: fromGhost, localBotId: 'spec-b' }, actorB)
+  const ghostLine = room.log.filter(entry => String(entry.text).includes('not verified')).at(-1)
+  assert.equal(ghostLine.authorId, '@chief.alice.home', 'an unverified roster entry never speaks under its own name')
+
+  // A Bot handle is a Bot's line: calling it a person's line in the envelope does not make it one, and an
+  // unverified handle is still said by the Bot that carried the line and marked unverified.
+  const humanClaim = encodeRoomShare({
+    op: 'line', roomId: 'alice-war', inviterName: 'Alice', inviterHome: '@alice.home',
+    inviterHandle: '@chief.b.alice.home', invitedHandle: '@chief.b.alice.home', seq: 8,
+    who: 'Ghost', authorKind: 'human', authorId: '@ghost.alice.home', text: 'as a person',
+  })
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: humanClaim, localBotId: 'spec-b' }, actorB)
+  const asPerson = room.log.filter(entry => String(entry.text).includes('as a person')).at(-1)
+  assert.equal(asPerson.authorKind, 'bot', 'a Bot handle never becomes a person because the envelope says so')
+  assert.equal(asPerson.authorId, '@chief.alice.home', 'and it is the Bot that carried the line that said it')
+  assert.equal(asPerson.unverified, true, 'the claim it failed to prove is marked unverified')
+  assert.equal(asPerson.botId, '@chief.alice.home')
+
+  // A verified Bot's own line needs no marker, and neither does a person's line from the other home.
+  const person = encodeRoomShare({
+    op: 'line', roomId: 'alice-war', inviterName: 'Alice', inviterHome: '@alice.home',
+    inviterHandle: '@chief.b.alice.home', invitedHandle: '@chief.b.alice.home', seq: 9,
+    who: 'Alice', authorKind: 'human', authorId: 'owner-a', text: 'a person here',
+  })
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: person, localBotId: 'spec-b' }, actorB)
+  const said = room.log.filter(entry => String(entry.text).includes('a person here')).at(-1)
+  assert.equal(said.authorKind, 'human')
+  assert.equal(said.authorId, 'owner-a')
+  assert.equal(said.unverified, undefined, 'a person\'s line from that home is not a Bot claim')
+
+  // The host's next roster is the current one: the Bots it no longer names leave this mirror.
+  const shrunk = encodeRoomShare({
+    op: 'join', roomId: 'alice-war', name: 'War room', inviterName: 'Alice',
+    inviterHome: '@alice.home', inviterHandle: '@chief.b.alice.home', invitedHandle: '@chief.b.alice.home', seq: 7,
+    roster: [
+      { handle: '@chief.a.home', name: 'Chief A', ownerName: 'Alice' },
+      { handle: '@chief.b.alice.home', name: 'Chief B', ownerName: 'Alice' },
+    ],
+  })
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: shrunk, localBotId: 'spec-b' }, actorB)
+  const after = room.participants.filter(p => p.leftSeq === undefined)
+  assert.deepEqual(after.filter(p => p.kind === 'bot' && p.remote).map(p => p.handle).sort(), ['@chief.a.home', '@chief.alice.home', '@chief.b.alice.home'], 'the seat that carried the join is not roster-controlled; the two it dropped are gone')
+  assert.equal(after.some(p => p.id === 'spec-b'), true, 'the guest\'s own Bot is not host-controlled')
+  // #904: identity is (home, handle). A Bot of another home is a different Bot even when the name
+  // matches, so a line it did not send cannot borrow its name here. The envelope itself cannot arrive
+  // from a home this room is not bound to at all (#909 refuses that before any attribution).
+  room.participants.push({
+    kind: 'bot', remote: true, id: '@chief.dup.home', handle: '@chief.dup.home', ownerHome: '@bob.home',
+    ownerName: 'Bob', displayName: 'Dup', role: 'member', verified: true, roomOnly: true, joinedSeq: 0, joinedAt: 1,
+  })
+  const crossHome = encodeRoomShare({
+    op: 'line', roomId: 'alice-war', inviterName: 'Alice', inviterHome: '@alice.home',
+    inviterHandle: '@chief.b.alice.home', invitedHandle: '@chief.b.alice.home', seq: 12,
+    who: 'Dup', authorKind: 'bot', authorId: '@chief.dup.home', text: 'cross home',
+  })
+  const intruder = await rt.applyInboundRoomShare({ fromHandle: '@chief.bob.home', fromHome: '@bob.home', text: crossHome, localBotId: 'spec-b' }, actorB)
+  assert.equal(intruder.refused, 'not-inviter', 'a home this room is not bound to cannot write into it')
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: crossHome, localBotId: 'spec-b' }, actorB)
+  const cross = room.log.filter(entry => String(entry.text).includes('cross home')).at(-1)
+  assert.equal(cross.authorId, '@chief.alice.home', 'another home\'s Bot name is not this room\'s Bot')
+  assert.equal(cross.unverified, true)
+
+  // A removed entry is a soft leave, not a deletion: its history stays resolvable.
+  const left = room.participants.filter(p => p.leftSeq !== undefined).map(p => p.handle || p.id).sort()
+  assert.deepEqual(left, ['@ghost.alice.home', '@writer.a.home', 'not-connected:offline bot'], 'a roster drop marks the entry left instead of deleting it')
+
+  // A line must not bring a removed Bot back: only a join does, so a removal cannot be undone by
+  // whoever keeps talking in the room.
+  const afterRemoval = encodeRoomShare({
+    op: 'line', roomId: 'alice-war', inviterName: 'Alice', inviterHome: '@alice.home',
+    inviterHandle: '@chief.b.alice.home', invitedHandle: '@chief.b.alice.home', seq: 6,
+    who: 'Alice', authorKind: 'human', authorId: 'owner-a', text: 'after removal',
+  })
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: afterRemoval, localBotId: 'spec-b' }, actorB)
+  assert.deepEqual(room.participants.filter(p => p.leftSeq !== undefined).map(p => p.handle || p.id).sort(), left, 'a line does not resurrect a removed Bot')
+
+  // The same join redelivered changes nothing: no second entry, no second participant.
+  const count = room.participants.length
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: shrunk, localBotId: 'spec-b' }, actorB)
+  assert.equal(room.participants.length, count, 'a redelivered join adds no second entry')
+
+  // A Bot the host puts back comes back in place: the existing entry clears its soft leave, no duplicate.
+  const back = encodeRoomShare({
+    op: 'join', roomId: 'alice-war', name: 'War room', inviterName: 'Alice',
+    inviterHome: '@alice.home', inviterHandle: '@chief.b.alice.home', invitedHandle: '@chief.b.alice.home', seq: 8,
+    roster: [
+      { handle: '@chief.a.home', name: 'Chief A', ownerName: 'Alice' },
+      { handle: '@chief.b.alice.home', name: 'Chief B', ownerName: 'Alice' },
+      { handle: '@writer.a.home', name: 'Writer A', ownerName: 'Alice' },
+    ],
+  })
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: back, localBotId: 'spec-b' }, actorB)
+  assert.deepEqual(room.members, ['spec-b'], 'a roster never writes into the room members')
+  const writers = room.participants.filter(p => p.handle === '@writer.a.home')
+  assert.equal(writers.length, 1, 'a Bot that comes back reuses its entry')
+  assert.equal(writers[0].leftSeq, undefined, 'and its soft leave is cleared')
+
+  // The host edits its notice and clears it: both ride the same join. Clearing is a present empty
+  // field; an absent field (an older host) is not an instruction to change anything.
+  const edited = encodeRoomShare({
+    op: 'join', roomId: 'alice-war', name: 'War room', inviterName: 'Alice',
+    inviterHome: '@alice.home', inviterHandle: '@chief.b.alice.home', invitedHandle: '@chief.b.alice.home', seq: 10,
+    notice: 'Edited notice.',
+  })
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: edited, localBotId: 'spec-b' }, actorB)
+  assert.equal(room.notice, 'Edited notice.', 'an edited notice follows on the next join')
+  const cleared = encodeRoomShare({
+    op: 'join', roomId: 'alice-war', name: 'War room', inviterName: 'Alice',
+    inviterHome: '@alice.home', inviterHandle: '@chief.b.alice.home', invitedHandle: '@chief.b.alice.home', seq: 11,
+    notice: '',
+  })
+  assert.equal(parseRoomShare(cleared).notice, '', 'a cleared notice is still carried, as an empty field')
+  assert.equal(parseRoomShare(encodeRoomShare({ op: 'join', roomId: 'alice-war', name: 'War room' })).notice, undefined, 'no notice field means "change nothing"')
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: cleared, localBotId: 'spec-b' }, actorB)
+  assert.equal(room.notice, '', 'clearing the notice clears the guest\'s copy')
+
+  // #904: a join that carries no roster field is not a request to empty the list. An older host, or a
+  // peer that drops the field, leaves the guest's participants exactly as they are.
+  const bare = encodeRoomShare({
+    op: 'join', roomId: 'alice-war', name: 'War room', inviterName: 'Alice',
+    inviterHome: '@alice.home', inviterHandle: '@chief.b.alice.home', invitedHandle: '@chief.b.alice.home', seq: 9,
+  })
+  const kept = room.participants.map(p => p.id)
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: bare, localBotId: 'spec-b' }, actorB)
+  assert.deepEqual(room.participants.map(p => p.id), kept, 'a join without a roster field changes nothing')
+
+  // #904: an explicit empty roster clears this home's Bots from the mirror — the seat, my own Bot and the
+  // person stay. (An absent field, just above, changes nothing.)
+  const emptied = encodeRoomShare({
+    op: 'join', roomId: 'alice-war', name: 'War room', inviterName: 'Alice',
+    inviterHome: '@alice.home', inviterHandle: '@chief.b.alice.home', invitedHandle: '@chief.b.alice.home', seq: 13,
+    roster: [],
+  })
+  assert.deepEqual(parseRoomShare(emptied).roster, [], 'an explicit empty roster is encoded instead of dropped')
+  await rt.applyInboundRoomShare({ fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: emptied, localBotId: 'spec-b' }, actorB)
+  assert.equal(room.participants.filter(p => p.fromRoster && p.leftSeq === undefined).length, 0, 'an empty roster leaves nobody of the host\'s from the roster')
+  assert.equal(room.participants.some(p => p.id === 'spec-b' && p.leftSeq === undefined), true, 'my own Bot is not controlled by the roster')
+  assert.equal(room.participants.some(p => p.handle === '@chief.alice.home' && p.leftSeq === undefined), true, 'the seat that carried the join stays')
+})
+
+// #904: a roster is stranger-written text, so the envelope that carries one is gated: only the room's
+// own inviter, only the room this mirror is bound to, and nothing it says widens reach by itself.
+test('#904: a roster from another home or for another room changes no participant', async (t) => {
+  const { rt } = host(t, TEAM)
+  await rt.load()
+  const { bob } = await signAliceAndBob(rt)
+  const actorB = await rt.authenticate(bob.sessionToken)
+  const join = {
+    op: 'join', roomId: 'alice-war', name: 'War room', inviterName: 'Alice',
+    inviterHome: '@alice.home', inviterHandle: '@chief.alice.home', invitedHandle: '@chief.b.alice.home', seq: 1,
+    notice: 'Alice\'s notice.',
+    roster: [{ handle: '@chief.a.home', name: 'Chief A', ownerName: 'Alice' }],
+  }
+  const first = await rt.applyInboundRoomShare({
+    fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: encodeRoomShare(join), localBotId: 'spec-b',
+  }, actorB)
+  const room = first.room
+  const before = room.participants.length
+
+  // Another home claims the same remote room id and names a Bot: the envelope is dropped whole.
+  const fromElsewhere = {
+    ...join, seq: 2, inviterHome: '@mallory.home', inviterHandle: '@mallory.home',
+    roster: [{ handle: '@mallory.bot.home', name: 'Mallory Bot', ownerName: 'Mallory' }],
+  }
+  await rt.applyInboundRoomShare({
+    fromHandle: '@mallory.home', fromHome: '@mallory.home', text: encodeRoomShare(fromElsewhere), localBotId: 'spec-b',
+  }, actorB)
+  assert.equal(rt.state.rooms[room.id].participants.length, before, 'a roster from a home that is not the inviter changes nothing')
+  assert.equal(rt.state.rooms[room.id].participants.some(p => p.handle === '@mallory.bot.home'), false)
+  assert.equal(rt.state.rooms[room.id].notice, "Alice's notice.", 'a joiner from another home does not rewrite the notice')
+
+  // A roster sent for another room id does not touch this mirror either.
+  const elsewhere = { ...join, roomId: 'other-room', seq: 3, notice: 'Mallory was here.', roster: [{ handle: '@eve.home', name: 'Eve', ownerName: 'Eve' }] }
+  await rt.applyInboundRoomShare({
+    fromHandle: '@chief.alice.home', fromHome: '@alice.home', text: encodeRoomShare(elsewhere), localBotId: 'spec-b',
+  }, actorB)
+  assert.equal(rt.state.rooms[room.id].participants.some(p => p.handle === '@eve.home'), false, 'another room id opens no slot here')
+  assert.equal(rt.state.rooms[room.id].participants.length, before)
+  assert.equal(rt.state.rooms[room.id].notice, "Alice's notice.", 'a join for another room id does not rewrite the notice')
+})
+
+// #904: the host side of the same envelope. The membership notice names this home's Bots by name and
+// owner, and a Bot with no Bot Social identity rides as not connected instead of being left out.
+test('#904: the membership notice carries the room\'s own Bots, and one without an identity as not connected', async (t) => {
+  const { rt, sent } = host(t, TEAM)
+  await rt.load()
+  const { alice } = await signAliceAndBob(rt)
+  const actorA = await rt.authenticate(alice.sessionToken)
+  publish(rt)
+  await grantToFriend(rt, 'chief-a')
+  await grantToFriend(rt, 'chief-b')
+  rt.state.bots['chief-b'].ownerId = 'owner-1'
+  const room = rt.state.rooms.war
+  rt.state.bots['chief-a'].fields = { social: { member: { handle: '@chief.a.home', home: '@alice.home', ownerName: 'Alice' } } }
+  rt.state.bots['chief-b'].fields = { social: { member: { handle: '@chief.b.home', home: '@alice.home', ownerName: 'Alice' } } }
+  room.members.push('spec-a')
+  room.participants.push({ kind: 'bot', id: 'spec-a', role: 'member', displayName: 'Writer A', joinedSeq: 0, joinedAt: 1 })
+  room.participants.push({ kind: 'bot', remote: true, id: '@coder.bob.home', handle: '@coder.bob.home', ownerHome: '@bob.home', ownerName: 'Bob', displayName: 'Coder', role: 'member', joinedSeq: 0, joinedAt: 1 })
+
+  assert.equal(rt.state.bots['chief-a'].fields.social.member.home, '@alice.home', 'fixture home')
+  assert.equal(room.participants.some(p => p.id === 'chief-a'), true, 'chief-a is a participant')
+  await rt.notifyRoomShare(room, { op: 'join', handle: '@coder.bob.home' })
+  const notice = parseRoomShare(sent.at(-1).text)
+  // #904: removing or adding one of *this home's* Bots has to send a fresh roster; the guest's list
+  // otherwise never changes and a removed Bot keeps writing.
+  const joins = () => sent.filter(m => m.text.includes('"op":"join"'))
+  await rt.removeRoomParticipant('war', { kind: 'bot', id: 'chief-b' }, actorA)
+  await new Promise(resolve => setTimeout(resolve, 0))
+  const afterRemove = parseRoomShare(joins().at(-1).text)
+  assert.equal(afterRemove.roster.some(entry => entry.handle === '@chief.b.home'), false, 'a local remove re-sends the roster without the Bot')
+  await rt.addRoomParticipant('war', { kind: 'bot', id: 'chief-b' }, actorA)
+  await new Promise(resolve => setTimeout(resolve, 0))
+  const afterAdd = parseRoomShare(joins().at(-1).text)
+  assert.equal(afterAdd.roster.some(entry => entry.handle === '@chief.b.home'), true, 'a local add re-sends the roster with the Bot')
+  assert.equal(notice.op, 'join')
+  room.notice = 'Keep it short.'
+  await rt.notifyRoomShare(room, { op: 'join', handle: '@coder.bob.home' })
+  const withNotice = parseRoomShare(sent.at(-1).text)
+  assert.equal(withNotice.notice, 'Keep it short.', 'the join carries the room\'s notice')
+  assert.deepEqual(notice.roster.map(entry => entry.handle ?? entry.name).sort(), ['@chief.a.home', '@chief.b.home', 'Writer A'])
+  assert.equal(notice.roster.find(entry => entry.handle === '@chief.a.home').home, '@alice.home', 'a roster entry names the home its handle is unique in')
+  const a = notice.roster.find(entry => entry.handle === '@chief.a.home')
+  assert.deepEqual({ name: a.name, ownerName: a.ownerName }, { name: 'Chief A', ownerName: 'Alice' })
+  const offline = notice.roster.find(entry => !entry.handle)
+  assert.equal(offline.connected, false, 'a Bot with no identity is listed as not connected, not dropped')
+  assert.equal(notice.roster.some(entry => entry.handle === '@coder.bob.home'), false, 'another home\'s Bot is not this home\'s to publish')
+
+  // A leave says only that someone left; it carries no roster.
+  await rt.notifyRoomShare(room, { op: 'leave', handle: '@coder.bob.home' })
+  assert.equal(parseRoomShare(sent.at(-1).text).roster, undefined)
+})
+
+// #904: the seat path attributes a line to the seat that carried it and never to the envelope's own
+// `authorId`: `ownSeatOf` matched that seat by the transport's `fromHandle`, so the seat already is the
+// Bot that wrote the line, while a claim inside the envelope is only the guest's word. This guards the
+// reverse "fix" (trust the claim) that would let a guest speak as any Bot in this home.
+test('#904: a seat\'s line is attributed to the seat, not to whatever the envelope claims', async (t) => {
+  const { rt } = host(t, TEAM)
+  await rt.load()
+  const { alice } = await signAliceAndBob(rt)
+  const actorA = await rt.authenticate(alice.sessionToken)
+  const room = rt.state.rooms.war
+  const ticket = 'AbCdEfGhIjKlMnOpQrStUv'
+  room.participants.push({
+    kind: 'bot', remote: true, id: '@chief.bob.home', handle: '@chief.bob.home', ownerHome: '@bob.home', ownerName: 'Bob',
+    displayName: 'Chief', role: 'member', admittedBy: 'ticket', ticket, hostBotId: 'chief-a', joinedSeq: 0, joinedAt: 1,
+  })
+  const line = (authorId, seq) => encodeRoomShare({
+    op: 'line', roomId: 'war', inviterHome: '@bob.home', inviterHandle: '@chief.bob.home',
+    seq, who: 'Chief', authorKind: 'bot', authorId, text: 'line ' + seq,
+  })
+  const ingest = (authorId, seq) => rt.applyInboundRoomShare({
+    fromHandle: '@chief.bob.home', fromHome: '@bob.home', text: line(authorId, seq),
+  }, actorA)
+
+  // A Bot of this home is not the seat: the claim falls back to the seat that carried the line.
+  await ingest('@writer.a.home', 1)
+  const forged = room.log.filter(entry => String(entry.text).includes('line 1')).at(-1)
+  assert.equal(forged.authorId, '@chief.bob.home', 'a guest cannot speak as a Bot of this home')
+  assert.equal(forged.botId, '@chief.bob.home')
+  assert.equal(forged.via, '@chief.bob.home')
+
+  // The seat is the author, and an invented handle is not adopted either.
+  await ingest('@chief.bob.home', 2)
+  const own = room.log.filter(entry => String(entry.text).includes('line 2')).at(-1)
+  assert.equal(own.authorId, '@chief.bob.home')
+  await ingest('@ghost.nobody', 3)
+  const invented = room.log.filter(entry => String(entry.text).includes('line 3')).at(-1)
+  assert.equal(invented.authorId, '@chief.bob.home', 'an invented handle never becomes an author')
+})
diff --git a/patches/ds-bot/files/test/room-ticket-seat.test.js b/patches/ds-bot/files/test/room-ticket-seat.test.js
index 5bac8562..230fb763 100644
--- a/patches/ds-bot/files/test/room-ticket-seat.test.js
+++ b/patches/ds-bot/files/test/room-ticket-seat.test.js
@@ -243,7 +243,8 @@ test('#884: a stranger claims a room link with two of its Bots, both are seated,
   const mirror = guestRoomOf(b.rt)
   assert.ok(mirror, 'the joins projected the room on the guest side')
   assert.equal(Object.values(b.rt.state.rooms).filter(r => r.origin === 'inbound-share').length, 1, 'one room for both seats')
-  assert.deepEqual(mirror.participants.filter(p => p.leftSeq === undefined && p.kind === 'bot').map(p => p.id).sort(), ['chief-b', 'helper-b'])
+  // #904: the guest also lists the host's Bot that carried the join; before that it listed no host Bot at all.
+  assert.deepEqual(mirror.participants.filter(p => p.leftSeq === undefined && p.kind === 'bot').map(p => p.id).sort(), ['@chief.alice.home', '@writer.alice.home', 'chief-b', 'helper-b'])
   assert.equal(mirror.sharedFrom.remoteRoomId, 'war')
   assert.equal(mirror.sharedFrom.ticket, invite.ticket)
   assert.equal(mirror.sharedFrom.inviterName, 'Alice', 'the guest reads the owner, never the host’s own "You"')