diff --git a/gateway/platforms/discord.py b/gateway/platforms/discord.py
index 79e70592e..3c222587e 100644
--- a/gateway/platforms/discord.py
+++ b/gateway/platforms/discord.py
@@ -2778,7 +2778,7 @@ class DiscordAdapter(BasePlatformAdapter):
         if not is_thread and not isinstance(message.channel, discord.DMChannel):
             no_thread_channels_raw = os.getenv("DISCORD_NO_THREAD_CHANNELS", "")
             no_thread_channels = {ch.strip() for ch in no_thread_channels_raw.split(",") if ch.strip()}
-            skip_thread = bool(channel_ids & no_thread_channels)
+            skip_thread = bool(channel_ids & no_thread_channels) or is_free_channel
             auto_thread = os.getenv("DISCORD_AUTO_THREAD", "true").lower() in ("true", "1", "yes")
             if auto_thread and not skip_thread and not is_voice_linked_channel:
                 thread = await self._auto_create_thread(message)
diff --git a/tests/gateway/test_discord_free_response.py b/tests/gateway/test_discord_free_response.py
index c2ef286d8..ee4f14e65 100644
--- a/tests/gateway/test_discord_free_response.py
+++ b/tests/gateway/test_discord_free_response.py
@@ -385,6 +385,33 @@ async def test_discord_voice_linked_channel_skips_mention_requirement_and_auto_t
     assert event.source.chat_type == "group"
 
 
+@pytest.mark.asyncio
+async def test_discord_free_channel_skips_auto_thread(adapter, monkeypatch):
+    """Free-response channels must NOT auto-create threads — bot replies inline.
+
+    Without this, every message in a free-response channel would spin off a
+    thread (since the channel bypasses the @mention gate), defeating the
+    lightweight-chat purpose of free-response mode.
+    """
+    monkeypatch.setenv("DISCORD_REQUIRE_MENTION", "true")
+    monkeypatch.setenv("DISCORD_FREE_RESPONSE_CHANNELS", "789")
+    monkeypatch.delenv("DISCORD_AUTO_THREAD", raising=False)  # default true
+
+    adapter._auto_create_thread = AsyncMock()
+
+    message = make_message(
+        channel=FakeTextChannel(channel_id=789),
+        content="free chat message",
+    )
+
+    await adapter._handle_message(message)
+
+    adapter._auto_create_thread.assert_not_awaited()
+    adapter.handle_message.assert_awaited_once()
+    event = adapter.handle_message.await_args.args[0]
+    assert event.source.chat_type == "group"
+
+
 @pytest.mark.asyncio
 async def test_discord_voice_linked_parent_thread_still_requires_mention(adapter, monkeypatch):
     """Threads under a voice-linked channel should still require @mention."""