CommandSignatureMismatch in slash commands

[lucamungo]

Hi,

I am trying to build a discord chatbot with slash commands. It looks like this

class ChatBot(commands.Bot):
    def __init__(
        self,
        generator: Generator,
        data: pd.DataFrame,
        channel_id: int,
        data_checked: pd.Timestamp,
    ):
        intents = discord.Intents.default()
        intents.message_content = True
        super().__init__(command_prefix='/', intents=intents)

        self._generator = generator
        self._data = data
        self._channel_id = channel_id

        self.data_checked = data_checked

    def __str__(self):
        return f"ChatBot(generator={self.generator}, data={self.data}, channel_id={self.channel_id})"

    @staticmethod
    def download_data(test: bool = False):
       ...
        return data

    @classmethod
    def from_env(cls, test: bool = False):
        ...
        return cls(generator=generator, data=data, channel_id=CHANNEL_ID, data_checked=today)

    @classmethod
    def from_model_path(cls, model_path: str, model_kwargs: dict = None):
        ...
        return cls(generator=generator, data=data, channel_id=CHANNEL_ID, data_checked=today)

    @property
    def generator(self):
        return self._generator

    @property
    def data(self):
        return self._data.copy()

    @property
    def channel_id(self):
        return self._channel_id

    def refresh_data(self):
        ...

    @staticmethod
    def to_prompt(message: str) -> str:
        return message_to_metric_prompt(message)

    def compute(self, request: MetricRequest) -> float:
        return compute_metric(self.data, request)

    def answer(self, **kwargs) -> str:
        return generate_response(**kwargs)

    async def setup_hook(self):
        try:
            print("Clearing existing commands...")
            self.tree.clear_commands(guild=discord.Object(id=GUILD_ID))  # Clear existing commands
            print("Adding command 'compute'")
            self.tree.add_command(self.compute_command)
            await self.tree.sync()  # Syncing globally
            print("Commands synced successfully.")
        except discord.app_commands.errors.CommandAlreadyRegistered:
            print("Command 'compute' already registered. Skipping...")

        # Print registered commands
        print("Current commands: ", self.tree.get_commands())

    async def on_ready(self):
        print(f"{self.user} has connected to Discord!")
        await self.setup_hook()

    @app_commands.command(name="compute", description="Compute a metric")
    async def compute_command(self, interaction: discord.Interaction, message: str):
        if interaction.channel_id != self._channel_id:
            await interaction.response.send_message("This command can only be used in the specified channel.",
                                                    ephemeral=True)
            return

        if is_help_request(message, self.user.id):
            await interaction.response.send_message(get_help_message(self.data))
            return

        await interaction.response.send_message("Let me help you with that. Please wait...")

        prompt = self.to_prompt(message)
        request = self.generator.generate_structured(prompt)
        metric = self.compute(request)
        response = self.answer(request=request, metric=metric, tag=interaction.user.id)
        await interaction.followup.send(response)
        

However, when I run it with

bot = ChatBot.from_env(test=args.test)
bot.run(TOKEN)

and I call the command, I get

Traceback (most recent call last):
  File "/Users/luca/anaconda3/envs/outlines/lib/python3.11/site-packages/discord/app_commands/tree.py", line 1248, in _call
    await command._invoke_with_namespace(interaction, namespace)
  File "/Users/luca/anaconda3/envs/outlines/lib/python3.11/site-packages/discord/app_commands/commands.py", line 853, in _invoke_with_namespace
    return await self._do_call(interaction, transformed_values)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/Users/luca/anaconda3/envs/outlines/lib/python3.11/site-packages/discord/app_commands/commands.py", line 841, in _do_call
    raise CommandSignatureMismatch(self) from None
discord.app_commands.errors.CommandSignatureMismatch: The signature for command 'compute' is different from the one provided by Discord. This can happen because either your code is out of date or you have not synced the commands with Discord, causing the mismatch in data. It is recommended to sync the command tree to fix this issue.

Could anybody help me with this?

[izxxr]

Last time you synced the commands, you had different parameters in compute_command. Sync the commands (tree) again to synchronize the signature (parameters) of command.

[AbstractUmbra]

The cause of this issue was correctly identified by @izxxr - you have changed your local command callback and it differs from the synced version Discord is sending for said callback.

You need to sync your CommandTree again, in the correct scope (global or specific guild).
See the documentation on sync. I can see in your setup_hook you clear commands within a specific Guild, but then sync globally, which leads me to believe there's a misunderstanding in what command exists where.

If you sync globally, and to a guild, then that guild will have two instances of said command.
You clear a guild command, but sync globally... You never sync that guild after clearing, so you're likely using an outdated command within that guild still.

[PhazonJim]

I am also facing this issue - I've sync'd globally and to specific guilds and I still face the same issue. The only way I could get the slash commands to work properly is by removing them from my subclass of commands.Bot and decorating the function definitions with @<bot instance>.tree.command . There appears to be an issue with using @app_command, I am wondering if the signature mismatch has to do with self coming through? @lucamungo did you have any luck?

[AbstractUmbra]

I am also facing this issue - I've sync'd globally and to specific guilds and I still face the same issue. The only way I could get the slash commands to work properly is by removing them from my subclass of commands.Bot and decorating the function definitions with @<bot instance>.tree.command . There appears to be an issue with using @app_command, I am wondering if the signature mismatch has to do with self coming through? @lucamungo did you have any luck?

This is the correct resolution to this. The library in most cases does what it can to allow self parameters to not cause issues in signature callbacks, however this is very intricate and messy to do, and as such we do not support the command signatures in the Bot subclass like this, rather making them free functions that are decorated with @Bot.tree.command() or supporting them via the commands.Cog subclasses using @app_commands.command() and akin.

[PhazonJim]

Ah makes sense. Is it possible to avoid the self issues by making the function a static method?

If it is not possible to define these methods under the subclass, is there a different recommendation/example for organizing bot code/subclasses? I have a working solution but just curious if there is "right" way to go about it.

Thanks!

[AbstractUmbra]

Untested but I can't envision why @staticmethod wouldn't work.

Generally most people will store their commands in the extension/Cog mechanisms.

[lucamungo]

As an additional bit of information, the code seems to break in commands.py, line 822

async def _do_call(self, interaction: Interaction, params: Dict[str, Any]) -> T:
        # These type ignores are because the type checker doesn't quite understand the narrowing here
        # Likewise, it thinks we're missing positional arguments when there aren't any.
        try:
            if self.binding is not None:
                return await self._callback(self.binding, interaction, **params)  # type: ignore
            return await self._callback(interaction, **params)  # type: ignore
        except TypeError as e:
            # In order to detect mismatch from the provided signature and the Discord data,
            # there are many ways it can go wrong yet all of them eventually lead to a TypeError
            # from the Python compiler showcasing that the signature is incorrect. This lovely
            # piece of code essentially checks the last frame of the caller and checks if the
            # locals contains our `self` reference.
            #
            # This is because there is a possibility that a TypeError is raised within the body
            # of the function, and in that case the locals wouldn't contain a reference to
            # the command object under the name `self`.
            frame = inspect.trace()[-1].frame
            if frame.f_locals.get('self') is self:
                raise CommandSignatureMismatch(self) from None
            raise CommandInvokeError(self, e) from e

because self._callback(interaction, **params) triggers the error

ChatBot.compute_command() missing 1 required positional argument: 'interaction'