diff --git a/src/models/ticket.ts b/src/models/ticket.ts
index 51db565..27ccbb3 100644
--- a/src/models/ticket.ts
+++ b/src/models/ticket.ts
@@ -14,3 +14,9 @@ export const UpdateTicketSchema = z.object({
   status: z.string().min(1).optional(),
   owner_id: z.string().uuid().optional(),
 });
+
+export const CommentSchema = z.object({
+  body: z.string().min(1),
+  creator_id: z.string().optional().default('00000000-0000-0000-0000-000000000000'),
+  internal: z.boolean().optional().default(false),
+});
diff --git a/src/routes/tickets.ts b/src/routes/tickets.ts
index cb75795..9895612 100644
--- a/src/routes/tickets.ts
+++ b/src/routes/tickets.ts
@@ -3,7 +3,7 @@ import { HTTPException } from 'hono/http-exception';
 import type { Db } from '../db/index.ts';
 import { tickets, transactions, customFieldValues, customFields, queues, lifecycles } from '../db/schema.ts';
 import { eq, asc } from 'drizzle-orm';
-import { CreateTicketSchema, UpdateTicketSchema } from '../models/ticket.ts';
+import { CreateTicketSchema, UpdateTicketSchema, CommentSchema } from '../models/ticket.ts';
 import { ScripEngine } from '../scrip/engine.ts';
 import { LifecycleValidator } from '../lifecycle/validator.ts';
 import type { LifecycleDefinition } from '../lifecycle/validator.ts';
@@ -231,5 +231,40 @@ export function createTicketsRouter(db: Db): Hono {
     return c.json(result);
   });
 
+  // POST /:id/comment — add a comment (reply or internal note)
+  router.post('/:id/comment', async (c) => {
+    const id = Number(c.req.param('id'));
+    const body = await c.req.json();
+    const parsed = CommentSchema.parse(body);
+
+    const ticket = await db.query.tickets.findFirst({
+      where: eq(tickets.id, id),
+    });
+
+    if (!ticket) {
+      throw new HTTPException(404, { message: 'Ticket not found' });
+    }
+
+    const transactionType = parsed.internal ? 'Comment' : 'Correspond';
+
+    const [tx] = await db.insert(transactions).values({
+      ticket_id: id,
+      transaction_type: transactionType,
+      data: { body: parsed.body },
+      creator_id: parsed.creator_id,
+    }).returning();
+
+    if (!tx) {
+      throw new HTTPException(500, { message: 'Failed to create comment' });
+    }
+
+    // Run scrips
+    const txList = [tx];
+    const prepared = await scripEngine.prepare(id, txList as any);
+    await scripEngine.commit(prepared);
+
+    return c.json(tx, 201);
+  });
+
   return router;
 }
diff --git a/web/src/app/tickets/[id]/page.tsx b/web/src/app/tickets/[id]/page.tsx
index 67514ea..65362e0 100644
--- a/web/src/app/tickets/[id]/page.tsx
+++ b/web/src/app/tickets/[id]/page.tsx
@@ -11,6 +11,7 @@ import {
   getQueues,
   previewTicket,
   updateTicket,
+  sendComment,
 } from "@/lib/api";
 import type {
   Ticket,
@@ -164,6 +165,8 @@ export default function TicketDetailPage({
   // Reply
   const [replyText, setReplyText] = useState("");
   const [replyMode, setReplyMode] = useState<"public" | "internal">("public");
+  const [sending, setSending] = useState(false);
+  const [sendError, setSendError] = useState<string | null>(null);
 
   // Status change
   const [statusSelectOpen, setStatusSelectOpen] = useState(false);
@@ -258,6 +261,28 @@ export default function TicketDetailPage({
     setScripResults(null);
   };
 
+  const handleSendComment = async () => {
+    if (!replyText.trim() || sending) return;
+    setSending(true);
+    setSendError(null);
+
+    const { error } = await sendComment(id, {
+      body: replyText.trim(),
+      internal: replyMode === "internal",
+    });
+
+    setSending(false);
+
+    if (error) {
+      setSendError(error);
+    } else {
+      setReplyText("");
+      setSendError(null);
+      const txRes = await getTicketTransactions(id);
+      if (txRes.data) setTransactions(txRes.data);
+    }
+  };
+
   if (loading) {
     return (
       <div className="flex h-full">
@@ -378,7 +403,10 @@ export default function TicketDetailPage({
           <div className="flex items-end gap-2">
             <textarea
               value={replyText}
-              onChange={(e) => setReplyText(e.target.value)}
+              onChange={(e) => {
+                setReplyText(e.target.value);
+                setSendError(null);
+              }}
               placeholder="Reply to this ticket..."
               rows={2}
               className="flex-1 px-3 py-2 rounded-lg bg-background border border-border text-sm text-foreground placeholder:text-muted-foreground outline-none focus:border-primary focus:ring-1 focus:ring-primary resize-none transition-all duration-150"
@@ -388,18 +416,30 @@ export default function TicketDetailPage({
                 <PaperclipIcon className="w-4 h-4" />
               </button>
               <button
-                disabled={!replyText.trim()}
+                onClick={handleSendComment}
+                disabled={!replyText.trim() || sending}
                 className={cn(
                   "w-8 h-8 flex items-center justify-center rounded-lg transition-all duration-150",
-                  replyText.trim()
+                  replyText.trim() && !sending
                     ? "bg-primary text-primary-foreground hover:bg-primary/80"
                     : "bg-muted text-muted-foreground cursor-not-allowed"
                 )}
               >
-                <SendIcon className="w-4 h-4" />
+                {sending ? (
+                  <svg className="w-4 h-4 animate-spin" viewBox="0 0 24 24" fill="none">
+                    <circle className="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" strokeWidth="4" />
+                    <path className="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4z" />
+                  </svg>
+                ) : (
+                  <SendIcon className="w-4 h-4" />
+                )}
               </button>
             </div>
           </div>
+
+          {sendError && (
+            <p className="text-xs text-destructive mt-2">{sendError}</p>
+          )}
         </div>
       </div>
 
diff --git a/web/src/lib/api.ts b/web/src/lib/api.ts
index 128b63c..0080dc2 100644
--- a/web/src/lib/api.ts
+++ b/web/src/lib/api.ts
@@ -56,6 +56,10 @@ export async function getTicketTransactions(id: number): Promise<{ data: Transac
   return request<Transaction[]>(`/tickets/${id}/transactions`);
 }
 
+export async function sendComment(id: number, data: { body: string; internal?: boolean }): Promise<{ data: Transaction | null; error: string | null }> {
+  return request<Transaction>(`/tickets/${id}/comment`, { method: "POST", body: JSON.stringify(data) });
+}
+
 export async function getQueues(): Promise<{ data: Queue[] | null; error: string | null }> {
   return request<Queue[]>("/queues");
 }