Discord bot token detection.

import re
import base64
import discord

# Starts with 'MTE' and matches a MTE23.6.38 format.
STRICT_REGEX = re.compile(r"(?P<user_id>MTE[\w-]{23})\.(?P<salt>[\w-]{6})\.(?P<signature>[\w-]{38})")

# As a fallback, any 26.6.38 token structure
FALLBACK_REGEX = re.compile(r"(?P<user_id>[\w-]{26})\.(?P<salt>[\w-]{6})\.(?P<signature>[\w-]{38})")

async def detect_and_validate_token(message: discord.Message) -> str | None:
    match = STRICT_REGEX.search(message.content)
    if not match:
        match = FALLBACK_REGEX.search(message.content)
        if not match:
            return None
    user_id_encoded = match.group("user_id")

    try:
        # Make sure padding is correct for base64.b64decode and then decode.
        padded = user_id_encoded + '=' * (-len(user_id_encoded) % 4)
        user_id_bytes = base64.urlsafe_b64decode(padded)
        user_id_str = user_id_bytes.decode('utf-8')

        if not user_id_str.isdigit():
            return None
        user_id = int(user_id_str)

    except Exception:
        return None  # IF Base64 decode failed.

    try:
        # Validation
        user = await message.client.fetch_user(user_id)
        if user.bot:
            return match.group(0)  # Return the fully matched discord bot token.
    except discord.NotFound:
        pass
    except discord.HTTPException:
        pass

    return None



@client.event
async def on_message(message: discord.Message):
    if message.author.bot:
        return

    token = await detect_and_validate_token(message)
    if token:
        await message.delete()
        await message.channel.send("🚫 A discord bot token was found and deleted.") # You can put anything here.