diff --git a/gateway/platforms/discord.py b/gateway/platforms/discord.py
index fcd2cbc996c..60cfb55ef67 100644
--- a/gateway/platforms/discord.py
+++ b/gateway/platforms/discord.py
@@ -2851,8 +2851,15 @@ class DiscordAdapter(BasePlatformAdapter):
             raw = os.getenv("DISCORD_FREE_RESPONSE_CHANNELS", "")
         if isinstance(raw, list):
             return {str(part).strip() for part in raw if str(part).strip()}
-        if isinstance(raw, str) and raw.strip():
-            return {part.strip() for part in raw.split(",") if part.strip()}
+        # Coerce non-list scalars (str/int/float) to str before splitting.
+        # YAML parses a bare numeric value such as
+        # `free_response_channels: 1491973769726791812` as int, which was
+        # previously falling through the isinstance(str) branch and silently
+        # returning an empty set.  str() here accepts whatever scalar the YAML
+        # loader hands us without changing existing string/CSV semantics.
+        s = str(raw).strip() if raw is not None else ""
+        if s:
+            return {part.strip() for part in s.split(",") if part.strip()}
         return set()
 
     def _thread_parent_channel(self, channel: Any) -> Any:
diff --git a/gateway/platforms/slack.py b/gateway/platforms/slack.py
index 9aa23871052..d35b703f70f 100644
--- a/gateway/platforms/slack.py
+++ b/gateway/platforms/slack.py
@@ -2888,6 +2888,13 @@ class SlackAdapter(BasePlatformAdapter):
             raw = os.getenv("SLACK_FREE_RESPONSE_CHANNELS", "")
         if isinstance(raw, list):
             return {str(part).strip() for part in raw if str(part).strip()}
-        if isinstance(raw, str) and raw.strip():
-            return {part.strip() for part in raw.split(",") if part.strip()}
+        # Coerce non-list scalars (str/int/float) to str before splitting.
+        # A bare numeric YAML value (`free_response_channels: 1234567890`) is
+        # loaded as int and was previously falling through the isinstance(str)
+        # branch to return an empty set.  str() here accepts whatever scalar
+        # the YAML loader hands us without changing existing string/CSV
+        # semantics.
+        s = str(raw).strip() if raw is not None else ""
+        if s:
+            return {part.strip() for part in s.split(",") if part.strip()}
         return set()
diff --git a/tests/gateway/test_discord_free_response.py b/tests/gateway/test_discord_free_response.py
index f1ee99606ec..f3242e3d5d5 100644
--- a/tests/gateway/test_discord_free_response.py
+++ b/tests/gateway/test_discord_free_response.py
@@ -220,6 +220,26 @@ async def test_discord_free_response_channel_can_come_from_config_extra(adapter,
     assert event.text == "allowed from config"
 
 
+def test_discord_free_response_channels_bare_int(adapter, monkeypatch):
+    # YAML `discord.free_response_channels: 1491973769726791812` (single bare
+    # integer) is loaded as an int and previously fell through the
+    # isinstance(str) branch in _discord_free_response_channels, silently
+    # returning an empty set.  Scalar → str coercion makes single-channel
+    # config work without having to quote the ID in YAML.
+    monkeypatch.delenv("DISCORD_FREE_RESPONSE_CHANNELS", raising=False)
+    adapter.config.extra["free_response_channels"] = 1491973769726791812
+
+    assert adapter._discord_free_response_channels() == {"1491973769726791812"}
+
+
+def test_discord_free_response_channels_int_list(adapter, monkeypatch):
+    # YAML list form with bare numeric entries — each element should be coerced.
+    monkeypatch.delenv("DISCORD_FREE_RESPONSE_CHANNELS", raising=False)
+    adapter.config.extra["free_response_channels"] = [1491973769726791812, 99999]
+
+    assert adapter._discord_free_response_channels() == {"1491973769726791812", "99999"}
+
+
 @pytest.mark.asyncio
 async def test_discord_forum_parent_in_free_response_list_allows_forum_thread(adapter, monkeypatch):
     monkeypatch.setenv("DISCORD_REQUIRE_MENTION", "true")
diff --git a/tests/gateway/test_slack_mention.py b/tests/gateway/test_slack_mention.py
index e6ba010de09..892cabef889 100644
--- a/tests/gateway/test_slack_mention.py
+++ b/tests/gateway/test_slack_mention.py
@@ -215,6 +215,23 @@ def test_free_response_channels_env_var_fallback(monkeypatch):
     assert OTHER_CHANNEL_ID in result
 
 
+def test_free_response_channels_bare_int():
+    # YAML `free_response_channels: 1491973769726791812` (single bare integer)
+    # is loaded as an int and would previously fall through the isinstance(str)
+    # branch to return an empty set.  Coerce scalar → str so single-channel
+    # config without quoting works as users expect.
+    adapter = _make_adapter(free_response_channels=1491973769726791812)
+    result = adapter._slack_free_response_channels()
+    assert result == {"1491973769726791812"}
+
+
+def test_free_response_channels_int_list():
+    # YAML list form with bare numeric entries — each element should be coerced.
+    adapter = _make_adapter(free_response_channels=[1491973769726791812, 99999])
+    result = adapter._slack_free_response_channels()
+    assert result == {"1491973769726791812", "99999"}
+
+
 # ---------------------------------------------------------------------------
 # Tests: mention gating integration (simulating _handle_slack_message logic)
 # ---------------------------------------------------------------------------