From 5e704ddc78a168fdc362a311a1c569a5ca655488 Mon Sep 17 00:00:00 2001
From: iliya <iliyazelenkog@gmail.com>
Date: Mon, 9 Mar 2026 20:53:45 +0200
Subject: [PATCH] feat: add cross-team messaging UI with team selector and
 visual distinction

- Team selector dropdown in MessageComposer (left of recipient selector)
- Cross-team mode locks recipient to team-lead, disables attachments
- Sender copy written to fromTeam inbox with source 'cross_team_sent'
- Purple accent styling for cross-team messages (incoming + outgoing)
- "from team-x" / "to team-x" badges in ActivityItem
- Strip [Cross-team from ...] prefix in UI (kept in stored text for CLI)
- CSS variables for cross-team theme (dark + light)
- Store: fetchCrossTeamTargets (all teams), sendCrossTeamMessage action
- Tests updated for sender copy and formatted text prefix
---
 src/main/services/team/CrossTeamService.ts    |  21 ++-
 src/main/services/team/TeamInboxWriter.ts     |   2 +-
 .../components/team/TeamDetailView.tsx        |  11 ++
 .../components/team/activity/ActivityItem.tsx |  81 ++++++--
 .../team/messages/MessageComposer.tsx         | 174 ++++++++++++++++--
 src/renderer/index.css                        |  10 +
 src/renderer/store/slices/teamSlice.ts        |  40 ++++
 src/shared/types/team.ts                      |   5 +-
 .../services/team/CrossTeamService.test.ts    |  20 +-
 9 files changed, 328 insertions(+), 36 deletions(-)

diff --git a/src/main/services/team/CrossTeamService.ts b/src/main/services/team/CrossTeamService.ts
index 327cefd6..6ddbcfaa 100644
--- a/src/main/services/team/CrossTeamService.ts
+++ b/src/main/services/team/CrossTeamService.ts
@@ -76,7 +76,7 @@ export class CrossTeamService {
     const formattedText = `[Cross-team from ${from} | depth:${chainDepth}]\n${text}`;
     const messageId = randomUUID();
 
-    // 5. Inbox write (TeamInboxWriter handles file lock + in-process lock internally)
+    // 5. Inbox write to TARGET team (TeamInboxWriter handles file lock + in-process lock internally)
     await this.inboxWriter.sendMessage(toTeam, {
       member: leadName,
       text: formattedText,
@@ -85,7 +85,24 @@ export class CrossTeamService {
       source: 'cross_team',
     });
 
-    // 6. Best-effort relay (if online)
+    // 6. Write "sent" copy to SENDER's inbox so the message appears in their activity
+    const senderLeadName = (await this.dataService.getLeadMemberName(fromTeam)) ?? 'team-lead';
+    void this.inboxWriter
+      .sendMessage(fromTeam, {
+        member: senderLeadName,
+        text,
+        from: 'user',
+        to: `${toTeam}.${leadName}`,
+        summary: summary ?? `Cross-team message to ${toTeam}`,
+        source: 'cross_team_sent',
+      })
+      .catch((e: unknown) => {
+        logger.warn(
+          `Failed to write sender copy for ${fromTeam}: ${e instanceof Error ? e.message : String(e)}`
+        );
+      });
+
+    // 7. Best-effort relay (if online)
     if (this.provisioning?.isTeamAlive(toTeam)) {
       void this.provisioning.relayLeadInboxMessages(toTeam).catch((e: unknown) => {
         logger.warn(`Cross-team relay to ${toTeam}: ${e instanceof Error ? e.message : String(e)}`);
diff --git a/src/main/services/team/TeamInboxWriter.ts b/src/main/services/team/TeamInboxWriter.ts
index e267b220..c8e55f07 100644
--- a/src/main/services/team/TeamInboxWriter.ts
+++ b/src/main/services/team/TeamInboxWriter.ts
@@ -23,7 +23,7 @@ export class TeamInboxWriter {
 
     const payload: InboxMessage = {
       from: request.from ?? 'user',
-      to: request.member,
+      to: request.to ?? request.member,
       text: request.text,
       timestamp: new Date().toISOString(),
       read: false,
diff --git a/src/renderer/components/team/TeamDetailView.tsx b/src/renderer/components/team/TeamDetailView.tsx
index a5f13521..905c35f6 100644
--- a/src/renderer/components/team/TeamDetailView.tsx
+++ b/src/renderer/components/team/TeamDetailView.tsx
@@ -215,6 +215,7 @@ export const TeamDetailView = ({ teamName }: TeamDetailViewProps): React.JSX.Ele
     updateTaskStatus,
     updateTaskOwner,
     sendTeamMessage,
+    sendCrossTeamMessage,
     requestReview,
     createTeamTask,
     startTask,
@@ -255,6 +256,7 @@ export const TeamDetailView = ({ teamName }: TeamDetailViewProps): React.JSX.Ele
       updateTaskStatus: s.updateTaskStatus,
       updateTaskOwner: s.updateTaskOwner,
       sendTeamMessage: s.sendTeamMessage,
+      sendCrossTeamMessage: s.sendCrossTeamMessage,
       requestReview: s.requestReview,
       createTeamTask: s.createTeamTask,
       startTask: s.startTask,
@@ -1567,6 +1569,15 @@ export const TeamDetailView = ({ teamName }: TeamDetailViewProps): React.JSX.Ele
                   });
                 });
               }}
+              onCrossTeamSend={(toTeam, text, summary) => {
+                void sendCrossTeamMessage({
+                  fromTeam: teamName,
+                  fromMember: 'user',
+                  toTeam,
+                  text,
+                  summary,
+                });
+              }}
             />
             <div className="mb-[35px]">
               <button
diff --git a/src/renderer/components/team/activity/ActivityItem.tsx b/src/renderer/components/team/activity/ActivityItem.tsx
index 702a3be6..0da9a82e 100644
--- a/src/renderer/components/team/activity/ActivityItem.tsx
+++ b/src/renderer/components/team/activity/ActivityItem.tsx
@@ -275,14 +275,37 @@ export const ActivityItem = ({
   const isManaged = isManagedCollapseState(collapseState);
   const isExpanded = isManaged ? !collapseState.isCollapsed : true;
 
+  const isCrossTeam = message.source === 'cross_team';
+  const isCrossTeamSent = message.source === 'cross_team_sent';
+  const isCrossTeamAny = isCrossTeam || isCrossTeamSent;
+  const crossTeamOrigin = useMemo(() => {
+    if (!isCrossTeam) return null;
+    const dot = message.from.indexOf('.');
+    if (dot <= 0 || dot === message.from.length - 1) return null;
+    return {
+      teamName: message.from.substring(0, dot),
+      memberName: message.from.substring(dot + 1),
+    };
+  }, [isCrossTeam, message.from]);
+  const crossTeamTarget = useMemo(() => {
+    if (!isCrossTeamSent || !message.to) return null;
+    const dot = message.to.indexOf('.');
+    if (dot <= 0) return message.to;
+    return message.to.substring(0, dot);
+  }, [isCrossTeamSent, message.to]);
+
   // Strip agent-only blocks + normalize escape sequences (before linkification)
   const strippedText = useMemo(() => {
     if (structured) return null;
-    const stripped = stripAgentBlocks(message.text).trim();
+    let stripped = stripAgentBlocks(message.text).trim();
     if (!stripped) return null; // All content was agent-only blocks → show summary instead
+    // Strip legacy cross-team prefix (e.g. "[Cross-team from team.lead | depth:0]\n")
+    if (isCrossTeamAny) {
+      stripped = stripped.replace(/^\[Cross-team from [^\]]+\]\n?/, '');
+    }
     // Normalize literal \n from historical CLI-produced text to real newlines
     return stripped.replace(/\\n/g, '\n').replace(/\\t/g, '\t');
-  }, [structured, message.text]);
+  }, [structured, message.text, isCrossTeamAny]);
 
   // Parse reply BEFORE linkification — linkifyMentionsInMarkdown transforms @name
   // into markdown links which breaks the reply regex matcher
@@ -325,7 +348,7 @@ export const ActivityItem = ({
 
   const isHeaderClickable = isManaged ? collapseState.canToggle : false;
   const showChevron = isHeaderClickable;
-  const isUserSent = message.source === 'user_sent';
+  const isUserSent = message.source === 'user_sent' || isCrossTeamSent;
   const isSystemMessage = message.from === 'system';
   const onManagedToggle = isManaged ? collapseState.onToggle : undefined;
   const handleHeaderToggle = isHeaderClickable
@@ -342,23 +365,29 @@ export const ActivityItem = ({
         backgroundColor:
           rateLimited || isApiError
             ? 'var(--tool-result-error-bg)'
-            : isSystemMessage
-              ? 'var(--system-activity-bg)'
-              : zebraShade
-                ? CARD_BG_ZEBRA
-                : CARD_BG,
+            : isCrossTeamAny
+              ? 'var(--cross-team-bg)'
+              : isSystemMessage
+                ? 'var(--system-activity-bg)'
+                : zebraShade
+                  ? CARD_BG_ZEBRA
+                  : CARD_BG,
         border:
           rateLimited || isApiError
             ? '1px solid var(--tool-result-error-border)'
-            : isSystemMessage
-              ? '1px solid var(--system-activity-border)'
-              : CARD_BORDER_STYLE,
+            : isCrossTeamAny
+              ? '1px solid var(--cross-team-border)'
+              : isSystemMessage
+                ? '1px solid var(--system-activity-border)'
+                : CARD_BORDER_STYLE,
         borderLeft:
           rateLimited || isApiError
             ? '3px solid var(--tool-result-error-text)'
-            : isSystemMessage
-              ? '3px solid var(--system-activity-accent)'
-              : `3px solid ${getThemedBorder(colors, isLight)}`,
+            : isCrossTeamAny
+              ? '3px solid var(--cross-team-accent)'
+              : isSystemMessage
+                ? '3px solid var(--system-activity-accent)'
+                : `3px solid ${getThemedBorder(colors, isLight)}`,
       }}
     >
       {/* Header — div with role=button (cannot use <button> due to nested buttons inside) */}
@@ -398,8 +427,8 @@ export const ActivityItem = ({
 
         {/* Sender avatar + name badge */}
         <MemberBadge
-          name={message.from}
-          color={memberColor ?? message.color}
+          name={crossTeamOrigin ? crossTeamOrigin.memberName : message.from}
+          color={isCrossTeamAny ? 'purple' : (memberColor ?? message.color)}
           hideAvatar={message.from === 'user' || message.from === 'system'}
           onClick={onMemberNameClick}
         />
@@ -433,6 +462,26 @@ export const ActivityItem = ({
           </span>
         ) : null}
 
+        {/* Cross-team origin badge */}
+        {isCrossTeam && crossTeamOrigin ? (
+          <span
+            className="inline-flex items-center gap-1 rounded-full px-1.5 py-0.5 text-[10px] font-medium tracking-wide"
+            style={{ backgroundColor: 'rgba(168, 85, 247, 0.15)', color: '#c084fc' }}
+          >
+            from {crossTeamOrigin.teamName}
+          </span>
+        ) : null}
+
+        {/* Cross-team sent badge */}
+        {isCrossTeamSent && crossTeamTarget ? (
+          <span
+            className="inline-flex items-center gap-1 rounded-full px-1.5 py-0.5 text-[10px] font-medium tracking-wide"
+            style={{ backgroundColor: 'rgba(168, 85, 247, 0.15)', color: '#c084fc' }}
+          >
+            to {crossTeamTarget}
+          </span>
+        ) : null}
+
         {/* Rate limit warning badge */}
         {rateLimited ? (
           <span className="inline-flex items-center gap-1 rounded-full bg-red-500/20 px-1.5 py-0.5 text-[10px] font-medium text-red-400">
diff --git a/src/renderer/components/team/messages/MessageComposer.tsx b/src/renderer/components/team/messages/MessageComposer.tsx
index ed947ea8..ef75fd1f 100644
--- a/src/renderer/components/team/messages/MessageComposer.tsx
+++ b/src/renderer/components/team/messages/MessageComposer.tsx
@@ -13,7 +13,16 @@ import { serializeChipsWithText } from '@renderer/types/inlineChip';
 import { formatAgentRole } from '@renderer/utils/formatAgentRole';
 import { buildMemberColorMap } from '@renderer/utils/memberHelpers';
 import { MAX_TEXT_LENGTH } from '@shared/constants';
-import { AlertCircle, Check, ChevronDown, ImagePlus, Mic, Search, Send } from 'lucide-react';
+import {
+  AlertCircle,
+  ArrowRightLeft,
+  Check,
+  ChevronDown,
+  ImagePlus,
+  Mic,
+  Search,
+  Send,
+} from 'lucide-react';
 
 import type { MentionSuggestion } from '@renderer/types/mention';
 import type { AttachmentPayload, LeadContextUsage, ResolvedTeamMember } from '@shared/types';
@@ -30,6 +39,7 @@ interface MessageComposerProps {
     summary?: string,
     attachments?: AttachmentPayload[]
   ) => void;
+  onCrossTeamSend?: (toTeam: string, text: string, summary?: string) => void;
 }
 
 /** Circular progress indicator for lead context usage. */
@@ -91,6 +101,7 @@ export const MessageComposer = ({
   sending,
   sendError,
   onSend,
+  onCrossTeamSend,
 }: MessageComposerProps): React.JSX.Element => {
   const [recipient, setRecipient] = useState<string>(() => {
     const lead = members.find((m) => m.role === 'lead' || m.name === 'team-lead');
@@ -105,6 +116,26 @@ export const MessageComposer = ({
   const [imageRestrictionError, setImageRestrictionError] = useState<string | null>(null);
   const imageRestrictionTimerRef = useRef(0);
 
+  // Cross-team state
+  const [selectedTeam, setSelectedTeam] = useState<string | null>(null);
+  const [teamSelectorOpen, setTeamSelectorOpen] = useState(false);
+  const allCrossTeamTargets = useStore((s) => s.crossTeamTargets);
+  const fetchCrossTeamTargets = useStore((s) => s.fetchCrossTeamTargets);
+
+  useEffect(() => {
+    void fetchCrossTeamTargets();
+  }, [fetchCrossTeamTargets]);
+
+  // Always filter out current team on the UI side (store is global, shared across tabs)
+  const crossTeamTargets = useMemo(
+    () => allCrossTeamTargets.filter((t) => t.teamName !== teamName),
+    [allCrossTeamTargets, teamName]
+  );
+
+  const isCrossTeam = selectedTeam !== null;
+  const targetDisplayName =
+    crossTeamTargets.find((t) => t.teamName === selectedTeam)?.displayName ?? selectedTeam;
+
   // Members load async with team data; keep recipient stable if valid, otherwise default to lead/first.
   useEffect(() => {
     if (recipient && members.some((m) => m.name === recipient)) {
@@ -150,7 +181,7 @@ export const MessageComposer = ({
   // const leadContext = useStore((s) =>
   //   isLeadAgentRecipient ? s.leadContextByTeam[teamName] : undefined
   // );
-  const supportsAttachments = isLeadRecipient;
+  const supportsAttachments = isLeadRecipient && !isCrossTeam;
   const canAttach = supportsAttachments && draft.canAddMore;
   const attachmentsBlocked = draft.attachments.length > 0 && !supportsAttachments;
   const canSend =
@@ -158,7 +189,8 @@ export const MessageComposer = ({
     trimmed.length > 0 &&
     trimmed.length <= MAX_TEXT_LENGTH &&
     !sending &&
-    !attachmentsBlocked;
+    !attachmentsBlocked &&
+    (!isCrossTeam || onCrossTeamSend !== undefined);
 
   // Track whether we initiated a send — clear draft only on confirmed success
   const pendingSendRef = useRef(false);
@@ -167,14 +199,28 @@ export const MessageComposer = ({
     if (!canSend) return;
     pendingSendRef.current = true;
     const serialized = serializeChipsWithText(trimmed, draft.chips);
-    // Summary should stay compact (no expanded chip markdown)
-    onSend(
-      recipient,
-      serialized,
-      trimmed,
-      draft.attachments.length > 0 ? draft.attachments : undefined
-    );
-  }, [canSend, recipient, trimmed, onSend, draft.attachments, draft.chips]);
+    if (isCrossTeam && selectedTeam && onCrossTeamSend) {
+      onCrossTeamSend(selectedTeam, serialized, trimmed);
+    } else {
+      // Summary should stay compact (no expanded chip markdown)
+      onSend(
+        recipient,
+        serialized,
+        trimmed,
+        draft.attachments.length > 0 ? draft.attachments : undefined
+      );
+    }
+  }, [
+    canSend,
+    recipient,
+    trimmed,
+    onSend,
+    onCrossTeamSend,
+    isCrossTeam,
+    selectedTeam,
+    draft.attachments,
+    draft.chips,
+  ]);
 
   // Clear draft only after send completes successfully (sending: true → false, no error)
   useEffect(() => {
@@ -352,11 +398,109 @@ export const MessageComposer = ({
             </span>
           ) : null}
 
-          <Popover open={recipientOpen} onOpenChange={setRecipientOpen}>
+          {/* Cross-team selector */}
+          {crossTeamTargets.length > 0 ? (
+            <Popover open={teamSelectorOpen} onOpenChange={setTeamSelectorOpen}>
+              <PopoverTrigger asChild>
+                <button
+                  type="button"
+                  className={cn(
+                    'inline-flex items-center gap-1.5 rounded-full border px-2.5 py-1 text-xs transition-colors',
+                    isCrossTeam
+                      ? 'border-[var(--cross-team-border)] bg-[var(--cross-team-bg)] text-purple-400 hover:border-purple-400/30'
+                      : 'border-[var(--color-border)] hover:border-[var(--color-border-emphasis)] hover:bg-[var(--color-surface-raised)]'
+                  )}
+                >
+                  {isCrossTeam ? (
+                    <>
+                      <ArrowRightLeft size={11} className="shrink-0" />
+                      <span className="max-w-[100px] truncate">{targetDisplayName}</span>
+                    </>
+                  ) : (
+                    <span className="text-[var(--color-text-secondary)]">This team</span>
+                  )}
+                  <ChevronDown size={12} className="shrink-0 text-[var(--color-text-muted)]" />
+                </button>
+              </PopoverTrigger>
+              <PopoverContent align="end" className="w-56 p-1.5">
+                <div className="max-h-48 space-y-0.5 overflow-y-auto">
+                  {/* Current team option */}
+                  <button
+                    type="button"
+                    className={cn(
+                      'flex w-full items-center gap-2 rounded-md px-2 py-1.5 text-left text-xs transition-colors hover:bg-[var(--color-surface-raised)]',
+                      !isCrossTeam && 'bg-[var(--color-surface-raised)]'
+                    )}
+                    onClick={() => {
+                      setSelectedTeam(null);
+                      setTeamSelectorOpen(false);
+                    }}
+                  >
+                    <span className="truncate text-[var(--color-text)]">This team</span>
+                    <span className="shrink-0 text-[10px] text-[var(--color-text-muted)]">
+                      current
+                    </span>
+                    {!isCrossTeam ? (
+                      <Check size={12} className="ml-auto shrink-0 text-blue-400" />
+                    ) : null}
+                  </button>
+
+                  {/* Separator */}
+                  <div className="my-1 h-px bg-[var(--color-border)]" />
+
+                  {/* Other teams */}
+                  {crossTeamTargets.map((target) => {
+                    const isSelected = selectedTeam === target.teamName;
+                    return (
+                      <button
+                        key={target.teamName}
+                        type="button"
+                        className={cn(
+                          'flex w-full items-center gap-2 rounded-md px-2 py-1.5 text-left text-xs transition-colors hover:bg-[var(--color-surface-raised)]',
+                          isSelected && 'bg-[var(--cross-team-bg)]'
+                        )}
+                        onClick={() => {
+                          setSelectedTeam(target.teamName);
+                          setRecipient('team-lead');
+                          setTeamSelectorOpen(false);
+                        }}
+                      >
+                        <ArrowRightLeft size={11} className="shrink-0 text-purple-400" />
+                        <div className="min-w-0 flex-1">
+                          <div className="truncate text-[var(--color-text)]">
+                            {target.displayName}
+                          </div>
+                          {target.description ? (
+                            <div className="truncate text-[10px] text-[var(--color-text-muted)]">
+                              {target.description}
+                            </div>
+                          ) : null}
+                        </div>
+                        {isSelected ? (
+                          <Check size={12} className="ml-auto shrink-0 text-purple-400" />
+                        ) : null}
+                      </button>
+                    );
+                  })}
+                </div>
+              </PopoverContent>
+            </Popover>
+          ) : null}
+
+          <Popover
+            open={isCrossTeam ? false : recipientOpen}
+            onOpenChange={isCrossTeam ? undefined : setRecipientOpen}
+          >
             <PopoverTrigger asChild>
               <button
                 type="button"
-                className="inline-flex items-center gap-1.5 rounded-full border border-[var(--color-border)] px-2.5 py-1 text-xs transition-colors hover:border-[var(--color-border-emphasis)] hover:bg-[var(--color-surface-raised)]"
+                className={cn(
+                  'inline-flex items-center gap-1.5 rounded-full border border-[var(--color-border)] px-2.5 py-1 text-xs transition-colors',
+                  isCrossTeam
+                    ? 'cursor-default opacity-60'
+                    : 'hover:border-[var(--color-border-emphasis)] hover:bg-[var(--color-surface-raised)]'
+                )}
+                disabled={isCrossTeam}
               >
                 {recipient ? (
                   <MemberBadge
@@ -462,7 +606,9 @@ export const MessageComposer = ({
         placeholder={
           isProvisioning
             ? 'Team is launching... message will be queued for inbox delivery.'
-            : 'Write a message... (Enter to send, Shift+Enter for new line)'
+            : isCrossTeam
+              ? `Cross-team message to ${targetDisplayName ?? 'team'}...`
+              : 'Write a message... (Enter to send, Shift+Enter for new line)'
         }
         value={draft.text}
         onValueChange={draft.setText}
diff --git a/src/renderer/index.css b/src/renderer/index.css
index dd151419..9edf7c1c 100644
--- a/src/renderer/index.css
+++ b/src/renderer/index.css
@@ -208,6 +208,11 @@
   --system-activity-border: rgba(59, 130, 246, 0.12);
   --system-activity-accent: rgba(96, 165, 250, 0.5);
 
+  /* Cross-team communication */
+  --cross-team-bg: rgba(168, 85, 247, 0.06);
+  --cross-team-border: rgba(168, 85, 247, 0.12);
+  --cross-team-accent: rgba(192, 132, 252, 0.5);
+
   /* Info style — banners, status indicators */
   --info-bg: rgba(59, 130, 246, 0.08);
   --info-border: rgba(59, 130, 246, 0.25);
@@ -471,6 +476,11 @@
   --system-activity-border: rgba(59, 130, 246, 0.25);
   --system-activity-accent: rgba(37, 99, 235, 0.7);
 
+  /* Cross-team communication */
+  --cross-team-bg: rgba(168, 85, 247, 0.08);
+  --cross-team-border: rgba(168, 85, 247, 0.25);
+  --cross-team-accent: rgba(124, 58, 237, 0.7);
+
   /* Info style — banners, status indicators */
   --info-bg: rgba(59, 130, 246, 0.1);
   --info-border: rgba(37, 99, 235, 0.3);
diff --git a/src/renderer/store/slices/teamSlice.ts b/src/renderer/store/slices/teamSlice.ts
index 6c2389ea..75bcfe94 100644
--- a/src/renderer/store/slices/teamSlice.ts
+++ b/src/renderer/store/slices/teamSlice.ts
@@ -69,6 +69,7 @@ import type {
   AddMemberRequest,
   CommentAttachmentPayload,
   CreateTaskRequest,
+  CrossTeamSendRequest,
   GlobalTask,
   KanbanColumnId,
   LeadActivityState,
@@ -295,6 +296,10 @@ export interface TeamSlice {
   selectTeam: (teamName: string, opts?: { skipProjectAutoSelect?: boolean }) => Promise<void>;
   refreshTeamData: (teamName: string) => Promise<void>;
   sendTeamMessage: (teamName: string, request: SendMessageRequest) => Promise<void>;
+  crossTeamTargets: { teamName: string; displayName: string; description?: string }[];
+  crossTeamTargetsLoading: boolean;
+  fetchCrossTeamTargets: () => Promise<void>;
+  sendCrossTeamMessage: (request: CrossTeamSendRequest) => Promise<void>;
   requestReview: (teamName: string, taskId: string) => Promise<void>;
   updateKanban: (teamName: string, taskId: string, patch: UpdateKanbanPatch) => Promise<void>;
   updateKanbanColumnOrder: (
@@ -438,6 +443,8 @@ export const createTeamSlice: StateCreator<AppState, [], [], TeamSlice> = (set,
   sendingMessage: false,
   sendMessageError: null,
   lastSendMessageResult: null,
+  crossTeamTargets: [],
+  crossTeamTargetsLoading: false,
   reviewActionError: null,
   provisioningRuns: {},
   provisioningStartedAtFloorByTeam: {},
@@ -873,6 +880,39 @@ export const createTeamSlice: StateCreator<AppState, [], [], TeamSlice> = (set,
     }
   },
 
+  fetchCrossTeamTargets: async () => {
+    set({ crossTeamTargetsLoading: true });
+    try {
+      const targets = await api.crossTeam.listTargets();
+      set({ crossTeamTargets: targets, crossTeamTargetsLoading: false });
+    } catch (error) {
+      logger.error('fetchCrossTeamTargets failed', error);
+      set({ crossTeamTargets: [], crossTeamTargetsLoading: false });
+    }
+  },
+
+  sendCrossTeamMessage: async (request: CrossTeamSendRequest) => {
+    set({ sendingMessage: true, sendMessageError: null, lastSendMessageResult: null });
+    try {
+      const result = await api.crossTeam.send(request);
+      set({
+        sendingMessage: false,
+        sendMessageError: null,
+        lastSendMessageResult: {
+          messageId: result.messageId,
+          deliveredToInbox: result.deliveredToInbox,
+        },
+      });
+      await get().refreshTeamData(request.fromTeam);
+    } catch (error) {
+      set({
+        sendingMessage: false,
+        lastSendMessageResult: null,
+        sendMessageError: mapSendMessageError(error),
+      });
+    }
+  },
+
   requestReview: async (teamName: string, taskId: string) => {
     try {
       set({ reviewActionError: null });
diff --git a/src/shared/types/team.ts b/src/shared/types/team.ts
index 5101c58e..31971375 100644
--- a/src/shared/types/team.ts
+++ b/src/shared/types/team.ts
@@ -251,7 +251,8 @@ export interface InboxMessage {
     | 'lead_process'
     | 'user_sent'
     | 'system_notification'
-    | 'cross_team';
+    | 'cross_team'
+    | 'cross_team_sent';
   attachments?: AttachmentMeta[];
   /** Lead session ID that produced this message (for session boundary detection). */
   leadSessionId?: string;
@@ -266,6 +267,8 @@ export interface SendMessageRequest {
   text: string;
   summary?: string;
   from?: string;
+  /** Override the `to` field in the stored message (defaults to `member`). */
+  to?: string;
   attachments?: AttachmentPayload[];
   source?: InboxMessage['source'];
   /** Lead session ID for session boundary detection. */
diff --git a/test/main/services/team/CrossTeamService.test.ts b/test/main/services/team/CrossTeamService.test.ts
index 43b16ad8..7e438b38 100644
--- a/test/main/services/team/CrossTeamService.test.ts
+++ b/test/main/services/team/CrossTeamService.test.ts
@@ -82,14 +82,30 @@ describe('CrossTeamService', () => {
 
       expect(result.deliveredToInbox).toBe(true);
       expect(result.messageId).toBeDefined();
-      expect(inboxWriter.sendMessage).toHaveBeenCalledOnce();
 
+      // First call: target team inbox, second call: sender copy (best-effort)
       const [teamName, req] = inboxWriter.sendMessage.mock.calls[0];
       expect(teamName).toBe('team-b');
       expect(req.member).toBe('team-lead');
       expect(req.source).toBe('cross_team');
       expect(req.from).toBe('team-a.lead');
-      expect(req.text).toContain('[Cross-team from team-a.lead | depth:0]');
+      expect(req.text).toBe('[Cross-team from team-a.lead | depth:0]\nHello from team-a');
+    });
+
+    it('writes sender copy to fromTeam inbox as user_sent', async () => {
+      await service.send(makeRequest());
+
+      // Wait for the best-effort sender copy (void promise)
+      await vi.waitFor(() => {
+        expect(inboxWriter.sendMessage).toHaveBeenCalledTimes(2);
+      });
+
+      const [senderTeam, senderReq] = inboxWriter.sendMessage.mock.calls[1];
+      expect(senderTeam).toBe('team-a');
+      expect(senderReq.from).toBe('user');
+      expect(senderReq.source).toBe('cross_team_sent');
+      expect(senderReq.to).toBe('team-b.team-lead');
+      expect(senderReq.text).toBe('Hello from team-a');
     });
 
     it('calls relayLeadInboxMessages when team is alive', async () => {