Discord bot slash command initialization error in Python

[Ryan_Innovative]

I’m building a Discord bot using Python for my class assignment and I keep getting an error when trying to initialize slash commands. The bot crashes right when it starts up with this error:

Traceback (most recent call last):
  File "d:\Projects\school\bot\main.py", line 10, in <module>
    commands_handler = SlashCommand(client, sync_commands=True)
                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Python311\Lib\site-packages\discord_slash\client.py", line 59, in __init__
    self._discord.loop.create_task(self.sync_all_commands(delete_from_unused_guilds))
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Python311\Lib\site-packages\discord\client.py", line 140, in __getattr__
    raise AttributeError(msg)
AttributeError: loop attribute cannot be accessed in non-async contexts. Consider using either an asynchronous main function and passing it to asyncio.run or using asynchronous initialisation hooks such as Client.setup_hook

Here’s my code:

import discord
import serial
from discord_slash import SlashCommand
from discord.ext import commands

intents = discord.Intents.all()

client = commands.Bot(command_prefix="!", intents=intents)

commands_handler = SlashCommand(client, sync_commands=True)

light_status = False

serial_connection = serial.Serial("COM5", baudrate=9600, timeout=1)

@client.event
async def on_ready():
    print(f"{client.user.name} has started")

@commands_handler.slash(name="activate", description="turn lights on")
async def activate_lights(ctx):
    serial_connection.write(b'1')
    await ctx.send("Lights have been activated")

client.run(TOKEN)

Can someone help me fix this issue?

[JollyMusic3]

Had this exact problem with my bot project last semester. You’re trying to access the event loop before the client initializes it. But honestly? Ditch discord-slash completely - it’s deprecated and breaks with newer discord.py versions. Just use the native slash commands in discord.py 2.0+. Swap out your SlashCommand setup for @app_commands.command() decorators and sync them with client.tree.sync() in setup_hook. Way cleaner and won’t break your assignment down the road.

[priya.in.pixels]

I see your problem. The discord-slash library’s trying to access the event loop before it’s ready, but there’s a better way to handle this.

Why wrestle with deprecated libraries and async headaches? Just automate the whole Discord bot workflow instead. I’ve built similar setups where bots control hardware through serial connections.

With Latenode, you create a visual workflow that handles Discord webhooks, processes commands, and triggers your serial device - no Python event loop issues. Set up Discord webhook triggers, add logic nodes for light control, and connect to hardware through HTTP requests or API calls.

You don’t need to worry about slash command registration, sync issues, or library compatibility. Latenode handles the async stuff while you focus on actual logic.

For your class assignment, you could show a more modern approach using visual automation instead of traditional coding. Your professor might be impressed.

Check it out: https://latenode.com

[bellagarcia]

yeah, you’re initializing SlashCommand before the event loop. move that line into your on_ready func or use setup_hook. but honestly, just drop discord-slash entirely - it’s dead and discord.py has built-in slash commands now.

[livbrown]

The Problem:

Your Discord bot is encountering a TypeError: parameter 'reason' is missing a type annotation in callback 'moderation.ban' error when attempting to use the /ban slash command. This happens even though you’ve provided a default value for the reason parameter. The bot connects and functions otherwise, but the /ban command fails due to this type error.

TL;DR: The Quick Fix:

Add a type annotation to the reason parameter in your /ban command definition. Change *, reason='No reason specified' to *, reason: str = 'No reason specified'.

Understanding the “Why” (The Root Cause):

Discord.py’s application commands (app_commands), used for slash commands, have stricter type-hinting requirements than traditional prefix commands. While providing a default value is good practice, application commands necessitate explicit type annotations for every parameter. The type-checking system within app_commands needs this explicit declaration to validate the type of your parameter, even with a default value supplied. Without the annotation, the type checker can’t verify the type of reason, resulting in the error. This is a crucial difference between prefix and slash commands that causes this error.

Step-by-Step Guide:

1. Add the Type Annotation: Locate your /ban command definition in your bot’s code. Modify the reason parameter to include its type annotation:

@app_commands.command(name='ban', description='Bans a user from the server if you have the necessary permissions.')
@has_permissions(ban_members=True)
async def ban(self, interaction: discord.Interaction, user: discord.Member, *, reason: str = 'No reason specified'):
    await interaction.response.send_message(f'{user} has been banned from the server.')
    await user.ban(reason=reason)

2. Implement Deferred Responses and Robust Error Handling: The original code sends a success message before attempting the ban. This is problematic because if the ban fails (due to permission issues, the user already being banned, etc.), the success message is inaccurate. It’s best practice to defer the response and then send a follow-up message after successfully banning the user. Also, handle potential errors gracefully:

@app_commands.command(name='ban', description='Bans a user from the server if you have the necessary permissions.')
@has_permissions(ban_members=True)
async def ban(self, interaction: discord.Interaction, user: discord.Member, *, reason: str = 'No reason specified'):
    await interaction.response.defer(ephemeral=False) # Defer the initial response, making it non-ephemeral for better feedback.
    try:
        await user.ban(reason=reason)
        await interaction.followup.send(f'{user} has been banned from the server.', ephemeral=False) # Non-ephemeral followup.
    except discord.HTTPException as e:
        await interaction.followup.send(f"Error banning {user}: {e}", ephemeral=False) # Inform user and developer of the error.
    except discord.Forbidden as e:
        await interaction.followup.send(f"I don't have permission to ban {user}", ephemeral=False) # Specific error message for permission issues.

Common Pitfalls & What to Check Next:

• Incorrect Import: Double-check that you have correctly imported app_commands from discord.ext.
• Missing Permissions: Ensure your bot has the Ban Members permission in the server.
• User Object Validity: Verify that the user object is a valid discord.Member object. Invalid user objects (e.g., a user who has left the server) will cause the ban to fail.
• Rate Limits: Discord enforces rate limits on actions like banning users. If you make many ban attempts in a short time, your requests might be throttled. Implement proper error handling for rate limits.

Still running into issues? Share your (sanitized) config files, the exact command you ran, and any other relevant details. The community is here to help!