diff --git a/nanobot/command/router.py b/nanobot/command/router.py
index eb2939847..ef35ea29b 100644
--- a/nanobot/command/router.py
+++ b/nanobot/command/router.py
@@ -5,11 +5,14 @@ from __future__ import annotations
import re
from contextlib import AbstractContextManager
from dataclasses import dataclass, field
+from difflib import get_close_matches
from typing import TYPE_CHECKING, Any, Awaitable, Callable
+from nanobot.bus.events import OutboundMessage
+
if TYPE_CHECKING:
from nanobot.agent.loop import AgentLoop
- from nanobot.bus.events import InboundMessage, OutboundMessage
+ from nanobot.bus.events import InboundMessage
from nanobot.session.manager import Session
from nanobot.utils.llm_runtime import LLMRuntime
@@ -80,18 +83,21 @@ class CommandRouter:
return normalize_command_text(text).lower() in self._priority
def is_dispatchable_command(self, text: str) -> bool:
- """Check whether *text* matches any non-priority command tier (exact or prefix).
+ """Check whether *text* should be handled by non-priority dispatch.
- Does NOT check priority tier.
- If this returns True, ``dispatch()`` is guaranteed to match a handler.
+ Exact priority commands are handled separately. Recognized non-priority
+ commands and invalid slash commands are dispatched here so malformed
+ commands can be rejected instead of reaching the LLM.
"""
cmd = normalize_command_text(text).lower()
+ if cmd in self._priority:
+ return False
if cmd in self._exact:
return True
for pfx, _ in self._prefix:
if cmd.startswith(pfx):
return True
- return False
+ return cmd.startswith("/")
async def dispatch_priority(self, ctx: CommandContext) -> OutboundMessage | None:
"""Dispatch a priority command. Called from run() without the lock."""
@@ -102,7 +108,7 @@ class CommandRouter:
return None
async def dispatch(self, ctx: CommandContext) -> OutboundMessage | None:
- """Try exact, then prefix handlers. Returns None if unhandled."""
+ """Try exact and prefix handlers, then reject invalid slash commands."""
ctx.raw = normalize_command_text(ctx.raw)
cmd = ctx.raw.lower()
@@ -114,4 +120,51 @@ class CommandRouter:
ctx.args = ctx.raw[len(pfx):]
return await handler(ctx)
- return None
+ return self._invalid_command_response(ctx)
+
+ def _invalid_command_response(self, ctx: CommandContext) -> OutboundMessage | None:
+ if not ctx.raw.startswith("/"):
+ return None
+
+ entered = ctx.raw.split(maxsplit=1)[0]
+ commands = self._registered_commands()
+ canonical = commands.get(entered.lower())
+ if canonical is not None:
+ accepts_args = any(
+ pfx.rstrip().lower() == entered.lower()
+ for pfx, _ in self._prefix
+ )
+ if accepts_args:
+ content = (
+ f'Invalid command "{entered}". '
+ 'Use "/help" to list available commands.'
+ )
+ else:
+ content = (
+ f'Command "{canonical}" does not accept arguments. '
+ f'Did you mean "{canonical}"?'
+ )
+ else:
+ matches = get_close_matches(entered.lower(), commands, n=1, cutoff=0.6)
+ if matches:
+ content = (
+ f'Unknown command "{entered}". '
+ f'Did you mean "{commands[matches[0]]}"?'
+ )
+ else:
+ content = (
+ f'Unknown command "{entered}". '
+ 'Use "/help" to list available commands.'
+ )
+
+ return OutboundMessage(
+ channel=ctx.msg.channel,
+ chat_id=ctx.msg.chat_id,
+ content=content,
+ metadata={**dict(ctx.msg.metadata or {}), "render_as": "text"},
+ )
+
+ def _registered_commands(self) -> dict[str, str]:
+ commands = [*self._priority, *self._exact]
+ commands.extend(pfx.rstrip() for pfx, _ in self._prefix)
+ return {command.lower(): command for command in commands if command}
diff --git a/tests/agent/test_loop_save_turn.py b/tests/agent/test_loop_save_turn.py
index f923de0c9..6ae74c675 100644
--- a/tests/agent/test_loop_save_turn.py
+++ b/tests/agent/test_loop_save_turn.py
@@ -218,6 +218,47 @@ async def test_new_with_bot_suffix_does_not_persist_command(tmp_path: Path) -> N
assert session.messages == []
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+ ("content", "expected"),
+ [
+ ("/neaw", 'Unknown command "/neaw". Did you mean "/new"?'),
+ (
+ "/status now",
+ 'Command "/status" does not accept arguments. Did you mean "/status"?',
+ ),
+ ],
+)
+async def test_invalid_slash_command_is_rejected_without_calling_provider(
+ tmp_path: Path,
+ content: str,
+ expected: str,
+) -> None:
+ loop = _make_full_loop(tmp_path)
+
+ response = await loop._process_message(
+ InboundMessage(
+ channel="websocket",
+ sender_id="user",
+ chat_id="chat-1",
+ content=content,
+ )
+ )
+
+ assert response is not None
+ assert response.content == expected
+ loop.provider.chat_with_retry.assert_not_awaited()
+ session = loop.sessions.get_or_create("websocket:chat-1")
+ persisted = [
+ (message["role"], message["content"], message.get("_command"))
+ for message in session.messages
+ ]
+ assert persisted == [
+ ("user", content, True),
+ ("assistant", response.content, True),
+ ]
+
+
def test_clean_generated_title_strips_reasoning_tags() -> None:
assert clean_generated_title("reasoning WebUI polish") == "WebUI polish"
assert clean_generated_title("Title: The user said hello") == ""
diff --git a/tests/command/test_router_dispatchable.py b/tests/command/test_router_dispatchable.py
index 837b55e23..697673ffe 100644
--- a/tests/command/test_router_dispatchable.py
+++ b/tests/command/test_router_dispatchable.py
@@ -70,9 +70,12 @@ class TestIsDispatchableCommand:
assert router.is_dispatchable_command(" /new ")
assert router.is_dispatchable_command(" /pairing list ")
- def test_unknown_slash_command_not_matched(self, router: CommandRouter) -> None:
- assert not router.is_dispatchable_command("/unknown")
- assert not router.is_dispatchable_command("/foo bar")
+ def test_invalid_slash_commands_match_for_explicit_rejection(
+ self, router: CommandRouter,
+ ) -> None:
+ assert router.is_dispatchable_command("/unknown")
+ assert router.is_dispatchable_command("/foo bar")
+ assert router.is_dispatchable_command("/status now")
@pytest.mark.parametrize(
@@ -183,6 +186,57 @@ class TestMidTurnCommandDispatchedDirectly:
result = await router.dispatch(ctx)
assert result is None
+ @pytest.mark.asyncio
+ async def test_unknown_command_suggests_close_match(
+ self, router: CommandRouter, fake_loop: MagicMock, fake_msg: MagicMock,
+ ) -> None:
+ fake_msg.content = "/neaw"
+ ctx = CommandContext(
+ msg=fake_msg, session=None,
+ key="test:chat1", raw="/neaw", loop=fake_loop,
+ )
+
+ result = await router.dispatch(ctx)
+
+ assert result is not None
+ assert result.content == 'Unknown command "/neaw". Did you mean "/new"?'
+ assert result.metadata["render_as"] == "text"
+
+ @pytest.mark.asyncio
+ async def test_exact_command_with_arguments_suggests_valid_form(
+ self, router: CommandRouter, fake_loop: MagicMock, fake_msg: MagicMock,
+ ) -> None:
+ fake_msg.content = "/status now"
+ ctx = CommandContext(
+ msg=fake_msg, session=None,
+ key="test:chat1", raw="/status now", loop=fake_loop,
+ )
+
+ result = await router.dispatch(ctx)
+
+ assert result is not None
+ assert result.content == (
+ 'Command "/status" does not accept arguments. Did you mean "/status"?'
+ )
+
+ @pytest.mark.asyncio
+ async def test_unknown_command_without_close_match_points_to_help(
+ self, router: CommandRouter, fake_loop: MagicMock, fake_msg: MagicMock,
+ ) -> None:
+ fake_msg.content = "/totally-unknown-command"
+ ctx = CommandContext(
+ msg=fake_msg, session=None,
+ key="test:chat1", raw="/totally-unknown-command", loop=fake_loop,
+ )
+
+ result = await router.dispatch(ctx)
+
+ assert result is not None
+ assert result.content == (
+ 'Unknown command "/totally-unknown-command". '
+ 'Use "/help" to list available commands.'
+ )
+
class TestPairingCommandDispatch:
"""Verify /pairing works via CommandRouter."""