diff --git a/ui/web/src/pages/agents/agent-detail/agent-files-tab.tsx b/ui/web/src/pages/agents/agent-detail/agent-files-tab.tsx
index f9c454fe..5762c82e 100644
--- a/ui/web/src/pages/agents/agent-detail/agent-files-tab.tsx
+++ b/ui/web/src/pages/agents/agent-detail/agent-files-tab.tsx
@@ -160,6 +160,7 @@ export function AgentFilesTab({
           canEdit={canEdit}
           onSave={handleSave}
           headerActions={aiActions || undefined}
+          contactSearchEnabled={isPredefined}
         />
       </div>
 
diff --git a/ui/web/src/pages/agents/agent-detail/file-sections/contact-insert-search.tsx b/ui/web/src/pages/agents/agent-detail/file-sections/contact-insert-search.tsx
new file mode 100644
index 00000000..f01963cd
--- /dev/null
+++ b/ui/web/src/pages/agents/agent-detail/file-sections/contact-insert-search.tsx
@@ -0,0 +1,89 @@
+import { useState, useEffect, useRef } from "react";
+import { Search, UserPlus } from "lucide-react";
+import { useTranslation } from "react-i18next";
+import { Badge } from "@/components/ui/badge";
+import { useContactSearch } from "../../hooks/use-contact-search";
+import type { ChannelContact } from "@/types/contact";
+
+/** Format a contact into a human-readable snippet for insertion into context files. */
+function formatContactSnippet(c: ChannelContact): string {
+  const parts: string[] = [];
+  if (c.display_name) parts.push(c.display_name);
+  if (c.username) parts.push(`@${c.username}`);
+  parts.push(`${c.channel_type}:${c.sender_id}`);
+  return `- ${parts.join(" — ")}`;
+}
+
+interface ContactInsertSearchProps {
+  onInsert: (text: string) => void;
+}
+
+export function ContactInsertSearch({ onInsert }: ContactInsertSearchProps) {
+  const { t } = useTranslation("agents");
+  const [search, setSearch] = useState("");
+  const [open, setOpen] = useState(false);
+  const { contacts } = useContactSearch(search);
+  const containerRef = useRef<HTMLDivElement>(null);
+
+  // Close on outside click
+  useEffect(() => {
+    if (!open) return;
+    const handler = (e: MouseEvent) => {
+      if (containerRef.current && !containerRef.current.contains(e.target as Node)) {
+        setOpen(false);
+      }
+    };
+    document.addEventListener("mousedown", handler);
+    return () => document.removeEventListener("mousedown", handler);
+  }, [open]);
+
+  const handleSelect = (c: ChannelContact) => {
+    onInsert(formatContactSnippet(c));
+    setSearch("");
+    setOpen(false);
+  };
+
+  return (
+    <div ref={containerRef} className="relative">
+      <div className="relative">
+        <Search className="absolute left-2 top-1/2 h-3.5 w-3.5 -translate-y-1/2 text-muted-foreground" />
+        <input
+          value={search}
+          onChange={(e) => { setSearch(e.target.value); setOpen(true); }}
+          onFocus={() => search.length >= 2 && setOpen(true)}
+          placeholder={t("files.insertContact")}
+          className="h-8 w-full max-w-sm rounded-md border bg-transparent pl-7 pr-2 text-xs placeholder:text-muted-foreground focus:outline-none focus:ring-1 focus:ring-ring"
+        />
+      </div>
+      {open && search.length >= 2 && contacts.length > 0 && (
+        <div className="absolute left-0 z-50 mt-1 max-h-48 w-full max-w-sm overflow-y-auto rounded-md border bg-popover p-1 shadow-md">
+          {contacts.map((c) => (
+            <button
+              key={c.id}
+              type="button"
+              onMouseDown={(e) => e.preventDefault()}
+              onClick={() => handleSelect(c)}
+              className="flex w-full items-center gap-2 rounded-sm px-2 py-1.5 text-left text-xs hover:bg-accent hover:text-accent-foreground"
+            >
+              <UserPlus className="h-3.5 w-3.5 shrink-0 text-muted-foreground" />
+              <div className="min-w-0 flex-1">
+                <div className="truncate font-medium">
+                  {c.display_name || c.sender_id}
+                </div>
+                <div className="flex items-center gap-1 text-[10px] text-muted-foreground">
+                  {c.username && <span>@{c.username}</span>}
+                  <Badge variant="outline" className="text-[9px] px-1 py-0">{c.channel_type}</Badge>
+                </div>
+              </div>
+            </button>
+          ))}
+        </div>
+      )}
+      {open && search.length >= 2 && contacts.length === 0 && (
+        <div className="absolute left-0 z-50 mt-1 w-full max-w-sm rounded-md border bg-popover p-3 text-center text-xs text-muted-foreground shadow-md">
+          {t("instances.noContactsFound")}
+        </div>
+      )}
+    </div>
+  );
+}
diff --git a/ui/web/src/pages/agents/agent-detail/file-sections/file-editor.tsx b/ui/web/src/pages/agents/agent-detail/file-sections/file-editor.tsx
index 390953b3..50395091 100644
--- a/ui/web/src/pages/agents/agent-detail/file-sections/file-editor.tsx
+++ b/ui/web/src/pages/agents/agent-detail/file-sections/file-editor.tsx
@@ -1,9 +1,10 @@
-import type { ReactNode } from "react";
+import { type ReactNode, useRef, useCallback } from "react";
 import { useTranslation } from "react-i18next";
 import { Save } from "lucide-react";
 import { Button } from "@/components/ui/button";
 import { Textarea } from "@/components/ui/textarea";
 import { FILE_DESCRIPTIONS } from "./file-utils";
+import { ContactInsertSearch } from "./contact-insert-search";
 
 interface FileEditorProps {
   fileName: string | null;
@@ -15,6 +16,8 @@ interface FileEditorProps {
   canEdit: boolean;
   onSave: () => void;
   headerActions?: ReactNode;
+  /** Show contact search box for inserting contact snippets into the editor. */
+  contactSearchEnabled?: boolean;
 }
 
 export function FileEditor({
@@ -27,8 +30,37 @@ export function FileEditor({
   canEdit,
   onSave,
   headerActions,
+  contactSearchEnabled,
 }: FileEditorProps) {
   const { t } = useTranslation("agents");
+  const textareaRef = useRef<HTMLTextAreaElement>(null);
+
+  const handleInsertText = useCallback(
+    (text: string) => {
+      const ta = textareaRef.current;
+      if (!ta) {
+        // Fallback: append at end
+        onChange(content + (content.endsWith("\n") ? "" : "\n") + text);
+        return;
+      }
+      const start = ta.selectionStart;
+      const end = ta.selectionEnd;
+      const before = content.slice(0, start);
+      const after = content.slice(end);
+      // Add newline prefix if cursor isn't at line start
+      const needNewline = before.length > 0 && !before.endsWith("\n");
+      const inserted = (needNewline ? "\n" : "") + text + "\n";
+      onChange(before + inserted + after);
+      // Restore cursor after inserted text
+      requestAnimationFrame(() => {
+        const pos = start + inserted.length;
+        ta.selectionStart = pos;
+        ta.selectionEnd = pos;
+        ta.focus();
+      });
+    },
+    [content, onChange],
+  );
 
   if (!fileName) {
     return (
@@ -64,12 +96,18 @@ export function FileEditor({
           )}
         </div>
       </div>
+      {contactSearchEnabled && canEdit && (
+        <div className="mb-2">
+          <ContactInsertSearch onInsert={handleInsertText} />
+        </div>
+      )}
       {loading && !content ? (
         <div className="flex flex-1 items-center justify-center text-sm text-muted-foreground">
           {t("files.loading")}
         </div>
       ) : (
         <Textarea
+          ref={textareaRef}
           value={content}
           onChange={(e) => {
             if (!canEdit) return;
diff --git a/ui/web/src/pages/agents/agent-detail/file-sections/file-sidebar.tsx b/ui/web/src/pages/agents/agent-detail/file-sections/file-sidebar.tsx
index e73ca484..7d77dbad 100644
--- a/ui/web/src/pages/agents/agent-detail/file-sections/file-sidebar.tsx
+++ b/ui/web/src/pages/agents/agent-detail/file-sections/file-sidebar.tsx
@@ -54,14 +54,11 @@ export function FileSidebar({
             <button
               key={file.name}
               type="button"
-              onClick={() => !userScoped && onSelect(file.name)}
-              disabled={userScoped}
+              onClick={() => onSelect(file.name)}
               className={`flex w-full items-center gap-2 rounded-md px-2.5 py-1.5 text-[13px] transition-colors ${
-                userScoped
-                  ? "cursor-not-allowed opacity-50"
-                  : active
-                    ? "bg-background text-foreground shadow-sm cursor-pointer"
-                    : "text-foreground hover:bg-background/60 cursor-pointer"
+                active
+                  ? "bg-background text-foreground shadow-sm cursor-pointer"
+                  : "text-foreground hover:bg-background/60 cursor-pointer"
               }`}
             >
               <FileText className="mt-0.5 h-3.5 w-3.5 shrink-0 self-start" />
diff --git a/ui/web/src/pages/agents/agent-detail/file-sections/index.ts b/ui/web/src/pages/agents/agent-detail/file-sections/index.ts
index 627067a3..a7046f2b 100644
--- a/ui/web/src/pages/agents/agent-detail/file-sections/index.ts
+++ b/ui/web/src/pages/agents/agent-detail/file-sections/index.ts
@@ -2,4 +2,5 @@ export { FileSidebar } from "./file-sidebar";
 export { FileEditor } from "./file-editor";
 export { RegenerateDialog } from "./regenerate-dialog";
 export { OpenAgentEmptyState } from "./open-agent-empty-state";
+export { ContactInsertSearch } from "./contact-insert-search";
 export { FILE_DESCRIPTIONS } from "./file-utils";