fix(gateway): honor configured slash-command refusal

(cherry picked from commit 8f052e0db1b33a5472473484d0a85aa72d476f73)

gateway/run_busy.py

@@ -1090,6 +1090,12 @@ class GatewayBusySessionMixin:
             "Slash command /%s denied for %s:%s (not admin, not in user_allowed_commands)",
             canonical_cmd, source.platform.value if source.platform else "?", source.user_id,
         )
+        platform_config = self.config.platforms.get(source.platform)
+        extra = getattr(platform_config, "extra", platform_config)
+        message = extra.get("command_denied_message") if isinstance(extra, dict) else None
+        if isinstance(message, str):
+            # Empty string is a silent denial, not permission: callers check ``is not None``.
+            return message
         allowed_preview = sorted(policy.user_allowed_commands)
         if allowed_preview:
             suffix = (

tests/gateway/test_slash_access_dispatch.py

@@ -155,6 +155,44 @@ async def test_non_admin_with_empty_user_commands_gets_floor_only():
     assert "Tier: user" in whoami_result
 
 
+@pytest.mark.asyncio
+@pytest.mark.parametrize("message", ["Please contact support.", ""])
+@pytest.mark.parametrize("entry", ["idle", "busy", "quick"])
+async def test_configured_denial_preserves_dispatch_gate(message, entry):
+    """Custom/empty refusals never grant execution (regression for #117217)."""
+    runner = _make_runner(platform_extra={
+        "allow_admin_from": ["111"], "command_denied_message": message,
+    })
+    source = _make_source(user_id="999")
+    runner._handle_restart_command = AsyncMock(side_effect=AssertionError("denied command ran"))
+    command = "/restart"
+    if entry == "busy":
+        key = build_session_key(source)
+        runner._running_agents[key] = MagicMock()
+        runner._running_agents_ts[key] = 0
+    elif entry == "quick":
+        runner.config.quick_commands = {"restricted": {"type": "alias", "target": "/restart"}}
+        command = "/restricted"
+    result = await runner._handle_message(_make_event(command, source))
+    assert result == message
+    runner._handle_restart_command.assert_not_awaited()
+
+
+@pytest.mark.parametrize("override", [None, False, 42, [], {}])
+def test_denial_override_keeps_default_and_authorization(override):
+    runner = _make_runner(platform_extra={"allow_admin_from": ["111"]})
+    source = _make_source(user_id="999")
+    original = runner._check_slash_access(source, "restart")
+    extra = runner.config.platforms[Platform.DISCORD].extra
+    extra["command_denied_message"] = override
+    assert runner._check_slash_access(source, "restart") == original
+    extra["command_denied_message"] = "custom"
+    assert runner._check_slash_access(_make_source(user_id="111"), "restart") is None
+    assert runner._check_slash_access(source, "help") is None
+    extra["user_allowed_commands"] = ["restart"]
+    assert runner._check_slash_access(source, "restart") is None
+
+
 # ---------------------------------------------------------------------------
 # Gate ALLOW — admin and listed user
 # ---------------------------------------------------------------------------

website/docs/user-guide/messaging/index.md

@@ -414,6 +414,26 @@ gateway:
 
 **Backward compat:** if `allow_admin_from` is not set for a scope, the tier split is disabled for that scope and every allowed user has full access. Existing installs keep working with no changes — opt in when you want the distinction.
 
+#### Customizing command refusals
+
+For customer-facing channels, set `command_denied_message` in the platform's
+`extra` block to replace the admin-only refusal with your own text:
+
+```yaml
+platforms:
+  telegram:
+    extra:
+      allow_admin_from: ["111"]
+      command_denied_message: "Please contact support for this request."
+```
+
+An empty string (`command_denied_message: ""`) silently rejects gated commands.
+Omitting the setting, using `null`, or providing a non-string retains the default
+refusal. Text is used literally, without placeholder expansion. This changes only
+the reply: denied commands remain blocked, including while an agent is busy.
+It does not hide `/help` or `/whoami`, change their always-allowed status, or
+suppress unrelated notices.
+
 #### Inspecting your access
 
 Use `/whoami` from any platform to see the active scope, your tier (admin / user / unrestricted), and which slash commands you can run. See the [Telegram](./telegram.md#slash-command-access-control) and [Discord](./discord.md#slash-command-access-control) pages for platform-specific examples.