diff --git a/gateway/channel_directory.py b/gateway/channel_directory.py
index 67d397fc10..627e525924 100644
--- a/gateway/channel_directory.py
+++ b/gateway/channel_directory.py
@@ -180,11 +180,16 @@ def _build_discord(adapter) -> List[Dict[str, str]]:
         import discord as _discord  # noqa: F401 — SDK presence check
     except ImportError:
         return channels
+    from gateway.platforms.helpers import is_discord_channel_obfuscated
+
     for guild in client.guilds:
         # Forum channels (type 15): creating a message auto-spawns a thread post.
         forums = getattr(guild, "forum_channels", None) or []
         for chs, ch_type in ((guild.text_channels, "channel"), (forums, "forum")):
             for ch in chs:
+                # Obfuscated placeholders (no VIEW_CHANNEL) can never be posted to. #90154
+                if is_discord_channel_obfuscated(ch):
+                    continue
                 channels.append({"id": str(ch.id), "name": ch.name, "guild": guild.name, "type": ch_type})
     # DM-capable users aren't reachable via guild enumeration; they come from sessions.
     channels.extend(_build_from_sessions("discord"))
diff --git a/gateway/platforms/helpers.py b/gateway/platforms/helpers.py
index d2c111fe13..3663d0b83d 100644
--- a/gateway/platforms/helpers.py
+++ b/gateway/platforms/helpers.py
@@ -537,6 +537,32 @@ def _chunk_newline_preferred(text, limit, len_fn):
     return chunks
 
 
+# ─── Discord channel obfuscation (Bot API change, mandatory Nov 16 2026) ───────
+# Channels a bot lacks VIEW_CHANNEL on are still dispatched over the Gateway with the
+# name replaced by "___hidden___", sensitive fields nulled and flag 1 << 17 set; over
+# HTTP they are omitted. https://discord.com/developers/docs/change-log (Aug 12, 2026)
+DISCORD_CHANNEL_OBFUSCATED_FLAG = 1 << 17
+DISCORD_OBFUSCATED_CHANNEL_NAME = "___hidden___"
+
+
+def is_discord_channel_obfuscated(channel) -> bool:
+    """True when a discord.py channel object is an obfuscated placeholder.
+
+    Skip these wherever guild channels are enumerated (channel directory, message
+    backfill): history reads and sends always fail with a permission error. Flag
+    first; the sentinel name is the fallback for discord.py builds that don't
+    expose the flag (a visible channel literally named ``___hidden___`` is then
+    also skipped — deliberate bias toward hiding). #90154
+    """
+    try:
+        flag_value = channel.flags.value
+    except AttributeError:
+        flag_value = None
+    if isinstance(flag_value, int) and flag_value & DISCORD_CHANNEL_OBFUSCATED_FLAG:
+        return True
+    return getattr(channel, "name", None) == DISCORD_OBFUSCATED_CHANNEL_NAME
+
+
 # ---- BEGIN PLUGIN-COMPAT (revert-scheduled; see COMPAT_MANIFEST.md) ----
 # Names external plugins imported from this module before the Sep 2026 decomposition.
 # Internal code MUST NOT use these (scripts/check_compat_pointers.py fails CI if it does).
diff --git a/plugins/platforms/discord/adapter.py b/plugins/platforms/discord/adapter.py
index f97bd894f6..d652a4b504 100644
--- a/plugins/platforms/discord/adapter.py
+++ b/plugins/platforms/discord/adapter.py
@@ -2280,8 +2280,18 @@ class DiscordAdapter(DiscordMediaMixin, BasePlatformAdapter):
         seen: set[str] = set()
         candidate_channels = []
         if "*" in channel_ids:
+            from gateway.platforms.helpers import is_discord_channel_obfuscated
+
             for guild in getattr(self._client, "guilds", []) or []:
-                candidate_channels.extend(getattr(guild, "text_channels", []) or [])
+                # Skip obfuscated placeholders (bot lacks VIEW_CHANNEL;
+                # Discord dispatches them with name "___hidden___" +
+                # CHANNEL_OBFUSCATED flag as of the Aug 2026 privacy
+                # change). History reads on them always fail.
+                candidate_channels.extend(
+                    ch
+                    for ch in (getattr(guild, "text_channels", []) or [])
+                    if not is_discord_channel_obfuscated(ch)
+                )
         else:
             for channel_id in sorted(channel_ids):
                 channel = None
diff --git a/tests/gateway/test_discord_channel_obfuscation.py b/tests/gateway/test_discord_channel_obfuscation.py
new file mode 100644
index 0000000000..4142337de4
--- /dev/null
+++ b/tests/gateway/test_discord_channel_obfuscation.py
@@ -0,0 +1,89 @@
+"""Tests for Discord channel-obfuscation handling.
+
+Discord's August 2026 privacy change ("Channel Obfuscation") dispatches
+channels a bot lacks VIEW_CHANNEL on with the name "___hidden___", flag
+1 << 17 (CHANNEL_OBFUSCATED) set, and sensitive fields nulled. Enumeration
+sites (channel directory, missed-message backfill) must skip these
+placeholders — the HTTP API omits them entirely starting Nov 16, 2026.
+"""
+
+import unittest
+from types import SimpleNamespace
+
+from gateway.platforms.helpers import (
+    DISCORD_CHANNEL_OBFUSCATED_FLAG,
+    DISCORD_OBFUSCATED_CHANNEL_NAME,
+    is_discord_channel_obfuscated,
+)
+
+
+def _channel(name="general", flag_value=0, cid=123):
+    return SimpleNamespace(
+        id=cid,
+        name=name,
+        flags=SimpleNamespace(value=flag_value),
+    )
+
+
+class TestIsDiscordChannelObfuscated(unittest.TestCase):
+    def test_normal_channel_not_obfuscated(self):
+        self.assertFalse(is_discord_channel_obfuscated(_channel()))
+
+    def test_flag_marks_obfuscated(self):
+        ch = _channel(name="whatever", flag_value=DISCORD_CHANNEL_OBFUSCATED_FLAG)
+        self.assertTrue(is_discord_channel_obfuscated(ch))
+
+    def test_flag_combined_with_other_flags(self):
+        ch = _channel(flag_value=DISCORD_CHANNEL_OBFUSCATED_FLAG | (1 << 4))
+        self.assertTrue(is_discord_channel_obfuscated(ch))
+
+    def test_sentinel_name_marks_obfuscated_without_flag(self):
+        # Older discord.py builds may not surface the new flag bit; the
+        # sentinel name is the fallback signal.
+        ch = _channel(name=DISCORD_OBFUSCATED_CHANNEL_NAME, flag_value=0)
+        self.assertTrue(is_discord_channel_obfuscated(ch))
+
+    def test_missing_flags_attribute(self):
+        ch = SimpleNamespace(id=1, name="ok")
+        self.assertFalse(is_discord_channel_obfuscated(ch))
+
+    def test_non_int_flag_value_falls_back_to_name(self):
+        ch = SimpleNamespace(id=1, name="ok", flags=SimpleNamespace(value=None))
+        self.assertFalse(is_discord_channel_obfuscated(ch))
+
+
+class TestChannelDirectorySkipsObfuscated(unittest.TestCase):
+    def test_build_discord_filters_hidden_channels(self):
+        from gateway import channel_directory as cd
+
+        visible = _channel(name="general", cid=1)
+        hidden_flag = _channel(name="secret", flag_value=DISCORD_CHANNEL_OBFUSCATED_FLAG, cid=2)
+        hidden_name = _channel(name=DISCORD_OBFUSCATED_CHANNEL_NAME, cid=3)
+        visible_forum = _channel(name="forum-open", cid=4)
+        hidden_forum = _channel(
+            name="forum-secret", flag_value=DISCORD_CHANNEL_OBFUSCATED_FLAG, cid=5
+        )
+
+        guild = SimpleNamespace(
+            name="TestGuild",
+            text_channels=[visible, hidden_flag, hidden_name],
+            forum_channels=[visible_forum, hidden_forum],
+        )
+        adapter = SimpleNamespace(_client=SimpleNamespace(guilds=[guild]))
+
+        original = cd._build_from_sessions
+        cd._build_from_sessions = lambda platform: []
+        try:
+            channels = cd._build_discord(adapter)
+        finally:
+            cd._build_from_sessions = original
+
+        ids = {c["id"] for c in channels}
+        self.assertEqual(ids, {"1", "4"})
+        types = {c["id"]: c["type"] for c in channels}
+        self.assertEqual(types["1"], "channel")
+        self.assertEqual(types["4"], "forum")
+
+
+if __name__ == "__main__":
+    unittest.main()