diff --git a/tests/e2e/conftest.py b/tests/e2e/conftest.py
index d9ca627c4..8e97b506f 100644
--- a/tests/e2e/conftest.py
+++ b/tests/e2e/conftest.py
@@ -12,7 +12,7 @@ No LLM, no real platform connections.
 import asyncio
 import sys
 import uuid
-from datetime import datetime
+from datetime import datetime, timezone, timezone
 from types import SimpleNamespace
 from unittest.mock import AsyncMock, MagicMock, patch
 
@@ -22,6 +22,7 @@ from gateway.config import GatewayConfig, Platform, PlatformConfig
 from gateway.platforms.base import MessageEvent, SendResult
 from gateway.session import SessionEntry, SessionSource, build_session_key
 
+E2E_MESSAGE_SETTLE_DELAY = 0.3
 
 # Platform library mocks
 
@@ -113,8 +114,9 @@ _ensure_telegram_mock()
 _ensure_discord_mock()
 _ensure_slack_mock()
 
-from gateway.platforms.discord import DiscordAdapter   # noqa: E402
+import discord  # noqa: E402 — mocked above
 from gateway.platforms.telegram import TelegramAdapter  # noqa: E402
+from gateway.platforms.discord import DiscordAdapter  # noqa: E402
 
 import gateway.platforms.slack as _slack_mod  # noqa: E402
 _slack_mod.SLACK_AVAILABLE = True
@@ -264,3 +266,140 @@ def runner(platform, session_entry):
 @pytest.fixture()
 def adapter(platform, runner):
     return make_adapter(platform, runner)
+
+
+# ═══════════════════════════════════════════════════════════════════════════
+# Discord helpers and fixtures
+# ═══════════════════════════════════════════════════════════════════════════
+
+BOT_USER_ID = 99999
+BOT_USER_NAME = "HermesBot"
+CHANNEL_ID = 22222
+GUILD_ID = 44444
+THREAD_ID = 33333
+MESSAGE_ID_COUNTER = 0
+
+
+def _next_message_id() -> int:
+    global MESSAGE_ID_COUNTER
+    MESSAGE_ID_COUNTER += 1
+    return 70000 + MESSAGE_ID_COUNTER
+
+
+def make_fake_bot_user():
+    return SimpleNamespace(
+        id=BOT_USER_ID, name=BOT_USER_NAME,
+        display_name=BOT_USER_NAME, bot=True,
+    )
+
+
+def make_fake_guild(guild_id: int = GUILD_ID, name: str = "Test Server"):
+    return SimpleNamespace(id=guild_id, name=name)
+
+
+def make_fake_text_channel(channel_id: int = CHANNEL_ID, name: str = "general", guild=None):
+    return SimpleNamespace(
+        id=channel_id, name=name,
+        guild=guild or make_fake_guild(),
+        topic=None, type=0,
+    )
+
+
+def make_fake_dm_channel(channel_id: int = 55555):
+    ch = MagicMock(spec=[])
+    ch.id = channel_id
+    ch.name = "DM"
+    ch.topic = None
+    ch.__class__ = discord.DMChannel
+    return ch
+
+
+def make_fake_thread(thread_id: int = THREAD_ID, name: str = "test-thread", parent=None):
+    th = MagicMock(spec=[])
+    th.id = thread_id
+    th.name = name
+    th.parent = parent or make_fake_text_channel()
+    th.parent_id = th.parent.id
+    th.guild = th.parent.guild
+    th.topic = None
+    th.type = 11
+    th.__class__ = discord.Thread
+    return th
+
+
+def make_discord_message(
+    *, content: str = "hello", author=None, channel=None, mentions=None,
+    attachments=None, message_id: int = None,
+):
+    if message_id is None:
+        message_id = _next_message_id()
+    if author is None:
+        author = SimpleNamespace(
+            id=11111, name="testuser", display_name="testuser", bot=False,
+        )
+    if channel is None:
+        channel = make_fake_text_channel()
+    if mentions is None:
+        mentions = []
+    if attachments is None:
+        attachments = []
+
+    return SimpleNamespace(
+        id=message_id, content=content, author=author, channel=channel,
+        mentions=mentions, attachments=attachments,
+        type=getattr(discord, "MessageType", SimpleNamespace()).default,
+        reference=None, created_at=datetime.now(timezone.utc),
+        create_thread=AsyncMock(),
+    )
+
+
+def get_response_text(adapter) -> str | None:
+    """Extract the response text from adapter.send() call args, or None if not called."""
+    if not adapter.send.called:
+        return None
+    return adapter.send.call_args[1].get("content") or adapter.send.call_args[0][1]
+
+
+def _make_discord_adapter_wired(runner=None):
+    """Create a DiscordAdapter wired to a GatewayRunner for e2e tests."""
+    if runner is None:
+        runner = make_runner(Platform.DISCORD)
+
+    config = PlatformConfig(enabled=True, token="e2e-test-token")
+    from gateway.platforms.helpers import ThreadParticipationTracker
+    with patch.object(ThreadParticipationTracker, "_load", return_value=set()):
+        adapter = DiscordAdapter(config)
+
+    bot_user = make_fake_bot_user()
+    adapter._client = SimpleNamespace(
+        user=bot_user,
+        get_channel=lambda _id: None,
+        fetch_channel=AsyncMock(),
+    )
+
+    adapter.send = AsyncMock(return_value=SendResult(success=True, message_id="e2e-resp-1"))
+    adapter.send_typing = AsyncMock()
+    adapter.set_message_handler(runner._handle_message)
+    runner.adapters[Platform.DISCORD] = adapter
+
+    return adapter, runner
+
+
+@pytest.fixture()
+def discord_setup():
+    return _make_discord_adapter_wired()
+
+
+@pytest.fixture()
+def discord_adapter(discord_setup):
+    return discord_setup[0]
+
+
+@pytest.fixture()
+def discord_runner(discord_setup):
+    return discord_setup[1]
+
+
+@pytest.fixture()
+def bot_user():
+    return make_fake_bot_user()
diff --git a/tests/e2e/test_discord_adapter.py b/tests/e2e/test_discord_adapter.py
new file mode 100644
index 000000000..97c806f82
--- /dev/null
+++ b/tests/e2e/test_discord_adapter.py
@@ -0,0 +1,106 @@
+"""Minimal e2e tests for Discord mention stripping + /command detection.
+
+Covers the fix for slash commands not being recognized when sent via
+@mention in a channel, especially after auto-threading.
+"""
+
+import asyncio
+from unittest.mock import AsyncMock
+
+import pytest
+
+from tests.e2e.conftest import (
+    BOT_USER_ID,
+    E2E_MESSAGE_SETTLE_DELAY,
+    get_response_text,
+    make_discord_message,
+    make_fake_dm_channel,
+    make_fake_thread,
+)
+
+pytestmark = pytest.mark.asyncio
+
+
+async def dispatch(adapter, msg):
+    await adapter._handle_message(msg)
+    await asyncio.sleep(E2E_MESSAGE_SETTLE_DELAY)
+
+
+class TestMentionStrippedCommandDispatch:
+    async def test_mention_then_command(self, discord_adapter, bot_user):
+        """<@BOT> /help → mention stripped, /help dispatched."""
+        msg = make_discord_message(
+            content=f"<@{BOT_USER_ID}> /help",
+            mentions=[bot_user],
+        )
+        await dispatch(discord_adapter, msg)
+        response = get_response_text(discord_adapter)
+        assert response is not None
+        assert "/new" in response
+
+    async def test_nickname_mention_then_command(self, discord_adapter, bot_user):
+        """<@!BOT> /help → nickname mention also stripped, /help works."""
+        msg = make_discord_message(
+            content=f"<@!{BOT_USER_ID}> /help",
+            mentions=[bot_user],
+        )
+        await dispatch(discord_adapter, msg)
+        response = get_response_text(discord_adapter)
+        assert response is not None
+        assert "/new" in response
+
+    async def test_text_before_command_not_detected(self, discord_adapter, bot_user):
+        """'<@BOT> something else /help' → mention stripped, but 'something else /help'
+        doesn't start with / so it's treated as text, not a command."""
+        msg = make_discord_message(
+            content=f"<@{BOT_USER_ID}> something else /help",
+            mentions=[bot_user],
+        )
+        await dispatch(discord_adapter, msg)
+        # Message is accepted (not dropped), but not dispatched as a command
+        discord_adapter.send.assert_awaited()
+        response = get_response_text(discord_adapter)
+        # /help command output lists /new — if it went through as text, it won't
+        assert response is None or "/new" not in response
+
+    async def test_no_mention_in_channel_dropped(self, discord_adapter):
+        """Message without @mention in server channel → silently dropped."""
+        msg = make_discord_message(content="/help", mentions=[])
+        await dispatch(discord_adapter, msg)
+        assert get_response_text(discord_adapter) is None
+
+    async def test_dm_no_mention_needed(self, discord_adapter):
+        """DMs don't require @mention — /help works directly."""
+        dm = make_fake_dm_channel()
+        msg = make_discord_message(content="/help", channel=dm, mentions=[])
+        await dispatch(discord_adapter, msg)
+        response = get_response_text(discord_adapter)
+        assert response is not None
+        assert "/new" in response
+
+
+class TestAutoThreadingPreservesCommand:
+    async def test_command_detected_after_auto_thread(self, discord_adapter, bot_user, monkeypatch):
+        """@mention /help in channel with auto-thread → thread created AND command dispatched."""
+        monkeypatch.setenv("DISCORD_AUTO_THREAD", "true")
+        fake_thread = make_fake_thread(thread_id=90001, name="help")
+        msg = make_discord_message(
+            content=f"<@{BOT_USER_ID}> /help",
+            mentions=[bot_user],
+        )
+
+        # Simulate discord.py restoring the original raw content (with mention)
+        # after create_thread(), which undoes any prior mention stripping.
+        original_content = msg.content
+
+        async def clobber_content(**kwargs):
+            msg.content = original_content
+            return fake_thread
+
+        msg.create_thread = AsyncMock(side_effect=clobber_content)
+        await dispatch(discord_adapter, msg)
+
+        msg.create_thread.assert_awaited_once()
+        response = get_response_text(discord_adapter)
+        assert response is not None
+        assert "/new" in response