diff --git a/ui/web/src/pages/agents/agent-detail/agent-detail-page.tsx b/ui/web/src/pages/agents/agent-detail/agent-detail-page.tsx
index 6692a235..ee2aebcf 100644
--- a/ui/web/src/pages/agents/agent-detail/agent-detail-page.tsx
+++ b/ui/web/src/pages/agents/agent-detail/agent-detail-page.tsx
@@ -10,6 +10,7 @@ import { AgentOverviewTab } from "./agent-overview-tab";
 import { AgentFilesTab } from "./agent-files-tab";
 import { AgentInstancesTab } from "./agent-instances-tab";
 import { AgentPermissionsTab } from "./agent-permissions-tab";
+import { AgentSharesTab } from "./agent-shares-tab";
 import { AgentEvolutionTab } from "./evolution-tab/agent-evolution-tab";
 import { AgentHooksTab } from "./agent-hooks-tab";
 import { SummoningModal } from "../summoning-modal";
@@ -80,6 +81,7 @@ export function AgentDetailPage({ agentId, onBack }: AgentDetailPageProps) {
               <TabsTrigger value="agent">{t("detail.tabs.agent")}</TabsTrigger>
               <TabsTrigger value="files">{t("detail.tabs.files")}</TabsTrigger>
               <TabsTrigger value="permissions">{t("detail.tabs.permissions")}</TabsTrigger>
+              <TabsTrigger value="shares">{t("detail.tabs.shares")}</TabsTrigger>
               <TabsTrigger value="evolution">{t("detail.tabs.evolution")}</TabsTrigger>
               <TabsTrigger value="hooks">{t("detail.tabs.hooks")}</TabsTrigger>
               {agent.agent_type === "predefined" && (
@@ -118,6 +120,10 @@ export function AgentDetailPage({ agentId, onBack }: AgentDetailPageProps) {
               <AgentPermissionsTab agentId={agentId} />
             </TabsContent>
 
+            <TabsContent value="shares" className="mt-4">
+              <AgentSharesTab agentId={agentId} />
+            </TabsContent>
+
             <TabsContent value="evolution" className="mt-4">
               <AgentEvolutionTab
                 agentId={agentId}
diff --git a/ui/web/src/pages/agents/agent-detail/agent-shares-tab.tsx b/ui/web/src/pages/agents/agent-detail/agent-shares-tab.tsx
new file mode 100644
index 00000000..66b309fc
--- /dev/null
+++ b/ui/web/src/pages/agents/agent-detail/agent-shares-tab.tsx
@@ -0,0 +1,198 @@
+import { useState, useCallback, useMemo } from "react";
+import { Plus, Trash2, Users } from "lucide-react";
+import { useTranslation } from "react-i18next";
+import { Button } from "@/components/ui/button";
+import { Label } from "@/components/ui/label";
+import { Badge } from "@/components/ui/badge";
+import { Combobox } from "@/components/ui/combobox";
+import {
+  Select,
+  SelectContent,
+  SelectItem,
+  SelectTrigger,
+  SelectValue,
+} from "@/components/ui/select";
+import { ConfirmDialog } from "@/components/shared/confirm-dialog";
+import { useHttp } from "@/hooks/use-ws";
+import { useContactPicker } from "@/hooks/use-contact-picker";
+import { useContactResolver } from "@/hooks/use-contact-resolver";
+import { useAgentShares } from "../hooks/use-agent-shares";
+import type { ChannelContact } from "@/types/contact";
+
+interface AgentSharesTabProps {
+  agentId: string;
+}
+
+const ROLE_OPTIONS = [
+  { value: "user" },
+  { value: "viewer" },
+] as const;
+
+function roleBadgeVariant(role: string) {
+  switch (role) {
+    case "owner": return "success" as const;
+    case "user": return "info" as const;
+    default: return "outline" as const;
+  }
+}
+
+export function AgentSharesTab({ agentId }: AgentSharesTabProps) {
+  const { t } = useTranslation("agents");
+  const http = useHttp();
+  const { shares, loading, addShare, revokeShare } = useAgentShares(agentId);
+  const [newUserId, setNewUserId] = useState("");
+  const [newRole, setNewRole] = useState("user");
+  const [revokeTarget, setRevokeTarget] = useState<string | null>(null);
+
+  // Contact picker for the add form
+  const listContacts = useCallback(
+    async (search: string): Promise<ChannelContact[]> => {
+      const res = await http.get<{ contacts: ChannelContact[] }>("/v1/contacts", {
+        search,
+        limit: "20",
+      });
+      return res.contacts ?? [];
+    },
+    [http],
+  );
+  const { options, searchContacts } = useContactPicker(listContacts);
+
+  // Resolve display names for existing shares
+  const shareUserIDs = useMemo(() => shares.map((s) => s.user_id), [shares]);
+  const { resolve } = useContactResolver(shareUserIDs);
+
+  const handleUserIdChange = (val: string) => {
+    setNewUserId(val);
+    searchContacts(val);
+  };
+
+  const handleAddShare = async () => {
+    if (!newUserId.trim()) return;
+    try {
+      await addShare(newUserId.trim(), newRole);
+      setNewUserId("");
+      setNewRole("user");
+    } catch {
+      // ignore
+    }
+  };
+
+  return (
+    <div className="max-w-2xl space-y-6">
+      {/* Add share form */}
+      <div className="rounded-lg border p-4">
+        <h3 className="mb-3 text-sm font-medium">{t("shares.grantAccess")}</h3>
+        <div className="flex flex-col gap-3 sm:flex-row sm:items-end">
+          <div className="flex-1 space-y-1.5">
+            <Label htmlFor="shareUserId">{t("shares.userId")}</Label>
+            <Combobox
+              value={newUserId}
+              onChange={handleUserIdChange}
+              options={options}
+              placeholder={t("shares.userIdPlaceholder")}
+            />
+          </div>
+          <div className="w-full space-y-1.5 sm:w-36">
+            <Label>{t("shares.role")}</Label>
+            <Select value={newRole} onValueChange={setNewRole}>
+              <SelectTrigger>
+                <SelectValue />
+              </SelectTrigger>
+              <SelectContent>
+                {ROLE_OPTIONS.map((opt) => (
+                  <SelectItem key={opt.value} value={opt.value}>
+                    {t(`shares.role.${opt.value}`)}
+                  </SelectItem>
+                ))}
+              </SelectContent>
+            </Select>
+          </div>
+          <Button onClick={handleAddShare} disabled={!newUserId.trim()} className="gap-1.5">
+            <Plus className="h-4 w-4" />
+            {t("shares.share")}
+          </Button>
+        </div>
+      </div>
+
+      {/* Share list */}
+      {loading && shares.length === 0 ? (
+        <div className="py-8 text-center text-sm text-muted-foreground">{t("shares.loadingShares")}</div>
+      ) : shares.length === 0 ? (
+        <div className="flex flex-col items-center gap-2 py-8 text-center">
+          <Users className="h-8 w-8 text-muted-foreground/50" />
+          <p className="text-sm text-muted-foreground">{t("shares.noShares")}</p>
+          <p className="text-xs text-muted-foreground">
+            {t("shares.noSharesDesc")}
+          </p>
+        </div>
+      ) : (
+        <div className="overflow-x-auto rounded-lg border">
+          <div className="grid min-w-[300px] grid-cols-[1fr_100px_48px] items-center gap-2 border-b bg-muted/50 px-4 py-2.5 text-xs font-medium text-muted-foreground">
+            <span>{t("shares.user")}</span>
+            <span>{t("shares.role")}</span>
+            <span />
+          </div>
+          {shares.map((share) => {
+            const contact = resolve(share.user_id);
+            const contactByGrant = share.granted_by ? resolve(share.granted_by) : null;
+            return (
+              <div
+                key={share.user_id}
+                className="grid min-w-[300px] grid-cols-[1fr_100px_48px] items-center gap-2 border-b px-4 py-3 last:border-0"
+              >
+                <div>
+                  <span className="text-sm font-medium">
+                    {contact?.display_name ?? share.user_id}
+                  </span>
+                  {contact?.display_name && (
+                    <span className="ml-1.5 text-xs text-muted-foreground font-mono">
+                      {share.user_id}
+                    </span>
+                  )}
+                  {contact?.username && (
+                    <span className="ml-1.5 text-xs text-muted-foreground">
+                      @{contact.username}
+                    </span>
+                  )}
+                  {share.granted_by && (
+                    <span className="ml-2 text-xs text-muted-foreground">
+                      by {contactByGrant?.display_name ?? share.granted_by}
+                    </span>
+                  )}
+                </div>
+                <Badge variant={roleBadgeVariant(share.role)}>{share.role}</Badge>
+                <Button
+                  variant="ghost"
+                  size="icon"
+                  className="h-8 w-8"
+                  onClick={() => setRevokeTarget(share.user_id)}
+                >
+                  <Trash2 className="h-3.5 w-3.5 text-destructive" />
+                </Button>
+              </div>
+            );
+          })}
+        </div>
+      )}
+
+      <ConfirmDialog
+        open={!!revokeTarget}
+        onOpenChange={() => setRevokeTarget(null)}
+        title={t("shares.revokeTitle")}
+        description={t("shares.revokeDesc", { userId: revokeTarget })}
+        confirmLabel={t("shares.revoke")}
+        variant="destructive"
+        onConfirm={async () => {
+          if (revokeTarget) {
+            try {
+              await revokeShare(revokeTarget);
+            } catch {
+              // ignore
+            }
+            setRevokeTarget(null);
+          }
+        }}
+      />
+    </div>
+  );
+}
diff --git a/ui/web/src/pages/agents/hooks/use-agent-shares.ts b/ui/web/src/pages/agents/hooks/use-agent-shares.ts
new file mode 100644
index 00000000..1a4d2ffa
--- /dev/null
+++ b/ui/web/src/pages/agents/hooks/use-agent-shares.ts
@@ -0,0 +1,48 @@
+import { useState, useEffect, useCallback } from "react";
+import { useHttp } from "@/hooks/use-ws";
+import type { AgentShareData } from "@/types/agent";
+
+export function useAgentShares(agentId: string) {
+  const http = useHttp();
+  const [shares, setShares] = useState<AgentShareData[]>([]);
+  const [loading, setLoading] = useState(false);
+
+  const loadShares = useCallback(async () => {
+    setLoading(true);
+    try {
+      const res = await http.get<{ shares: AgentShareData[] }>(
+        `/v1/agents/${agentId}/shares`,
+      );
+      setShares(res.shares ?? []);
+    } catch {
+      // ignore
+    } finally {
+      setLoading(false);
+    }
+  }, [http, agentId]);
+
+  useEffect(() => {
+    loadShares();
+  }, [loadShares]);
+
+  const addShare = useCallback(
+    async (userId: string, role: string) => {
+      await http.post(`/v1/agents/${agentId}/shares`, {
+        user_id: userId,
+        role,
+      });
+      loadShares();
+    },
+    [http, agentId, loadShares],
+  );
+
+  const revokeShare = useCallback(
+    async (userId: string) => {
+      await http.delete(`/v1/agents/${agentId}/shares/${userId}`);
+      loadShares();
+    },
+    [http, agentId, loadShares],
+  );
+
+  return { shares, loading, refresh: loadShares, addShare, revokeShare };
+}