Context

Understanding and using the Context object in command handlers

The Context object contains information about a command invocation. It’s automatically passed as the first parameter to all command functions.

Basic Usage

@bot.command()
async def mycommand(ctx):
    # ctx is the Context object
    await ctx.send('Hello!')

In cogs, ctx is the second parameter (after self):

class MyCog(commands.Cog):
    @commands.command()
    async def mycommand(self, ctx):
        await ctx.send('Hello from cog!')

Context Attributes

Message Information

@bot.command()
async def info(ctx):
    # The message that triggered the command
    message = ctx.message
    await ctx.send(f'Content: {message.content}')
    await ctx.send(f'Created: {message.created_at}')

Bot Reference

@bot.command()
async def botinfo(ctx):
    # Reference to the bot instance
    bot = ctx.bot
    await ctx.send(f'Bot: {bot.user.display_name}')
    await ctx.send(f'Commands: {len(bot.commands)}')

Author Information

@bot.command()
async def whoami(ctx):
    # The user who invoked the command
    author = ctx.author
    await ctx.send(f'You are: {author.display_name}')
    await ctx.send(f'ID: {author.id}')

The author is either a Friend (for DM messages) or PartyMember (for party messages).

Party Information

@bot.command()
async def partyinfo(ctx):
    # The party where the command was used (None if DM)
    if ctx.party:
        await ctx.send(f'Party ID: {ctx.party.id}')
        await ctx.send(f'Members: {len(ctx.party.members)}')
    else:
        await ctx.send('Not in a party!')

Command Information

@bot.command()
async def commandinfo(ctx):
    # The command being invoked
    cmd = ctx.command
    await ctx.send(f'Command: {cmd.name}')
    await ctx.send(f'Qualified: {cmd.qualified_name}')
    await ctx.send(f'Help: {cmd.help}')

Prefix Information

@bot.command()
async def prefixinfo(ctx):
    # The prefix used to invoke the command
    await ctx.send(f'Prefix used: {ctx.prefix}')
    
    # The exact command name used (useful for aliases)
    await ctx.send(f'Invoked with: {ctx.invoked_with}')

Context Methods

Sending Messages

@bot.command()
async def greet(ctx):
    # Send to the destination (party or DM)
    await ctx.send('Hello!')

This sends to the party if the command was used in a party, or to the DM if used in a DM.

Getting Destination

@bot.command()
async def destination(ctx):
    dest = ctx.get_destination()
    # dest is either the party or the friend
    await dest.send('Message to destination')

Invoking Commands

Manually invoke a command:

@bot.command()
async def repeat(ctx):
    # Invoke another command
    hello_cmd = bot.get_command('hello')
    await ctx.invoke(hello_cmd)

Re-invoking Commands

Re-run the current command:

@bot.command()
async def retry(ctx):
    try:
        # Command logic
        await risky_operation()
    except Exception:
        # Retry the command
        await ctx.reinvoke()

Parameters:

• call_hooks - Whether to call before/after invoke hooks
• restart - Start from the root command or current position

await ctx.reinvoke(call_hooks=True, restart=False)

Context Properties

Valid Context

@bot.command()
async def check(ctx):
    if ctx.valid:
        await ctx.send('Valid invocation!')

A context is valid if it has a prefix and a command.

Cog Reference

@bot.command()
async def coginfo(ctx):
    if ctx.cog:
        await ctx.send(f'Cog: {ctx.cog.qualified_name}')
    else:
        await ctx.send('Not in a cog')

Friend and Member

@bot.command()
async def friendinfo(ctx):
    # Get Friend object (None if not friends)
    friend = ctx.friend
    if friend:
        await ctx.send(f'Friend: {friend.display_name}')
    
    # Get PartyMember object (None if not in same party)
    member = ctx.member
    if member:
        await ctx.send(f'Member: {member.display_name}')
        await ctx.send(f'Ready: {member.ready}')

Me (Self)

@bot.command()
async def me(ctx):
    # The bot's user object
    me = ctx.me
    if ctx.party:
        # In a party, returns ClientPartyMember
        await ctx.send(f'My outfit: {me.outfit}')
    else:
        # In DM, returns ClientUser
        await ctx.send(f'My name: {me.display_name}')

Subcommands

@bot.group()
async def manage(ctx):
    if ctx.invoked_subcommand is None:
        await ctx.send('Use a subcommand!')

@manage.command()
async def start(ctx):
    await ctx.send('Starting...')

@manage.command()
async def stop(ctx):
    await ctx.send('Stopping...')

Subcommand Attributes

@bot.group()
async def config(ctx):
    # The subcommand that was invoked
    if ctx.invoked_subcommand:
        await ctx.send(f'Running: {ctx.invoked_subcommand.name}')
    
    # The string passed to call a subcommand
    if ctx.subcommand_passed:
        await ctx.send(f'Passed: {ctx.subcommand_passed}')

Command Arguments

Access parsed command arguments:

@bot.command()
async def echo(ctx, *, message: str):
    # Access through parameters
    await ctx.send(message)
    
    # Or through ctx.args and ctx.kwargs
    await ctx.send(f'Args: {ctx.args}')
    await ctx.send(f'Kwargs: {ctx.kwargs}')

Command Failure

Check if a command failed:

@bot.event
async def event_command_completion(ctx):
    if ctx.command_failed:
        await ctx.send('Command failed!')
    else:
        await ctx.send('Command succeeded!')

Help Command Integration

Send help for a command or cog:

@bot.command()
async def help_me(ctx):
    # Show general help
    await ctx.send_help()
    
    # Show help for a specific command
    await ctx.send_help('ping')
    
    # Show help for a cog
    await ctx.send_help('General')
    
    # With pagination
    await ctx.send_help(page=2)

Parameters:

• entity - Command, cog, or string name (optional)
• page - Page number for paginated help (default: 1)

Custom Context

Create a custom context class:

class MyContext(commands.Context):
    async def send(self, content: str):
        # Add custom behavior
        content = f'[Bot] {content}'
        return await super().send(content)
    
    async def tick(self):
        """Helper method to send a checkmark."""
        await self.send('✓')

bot = commands.Bot(
    command_prefix='!',
    auth=auth
)

@bot.event
async def event_ready():
    print('Ready!')

# Use custom context
@bot.command()
async def test(ctx: MyContext):
    await ctx.send('Testing')
    await ctx.tick()

Getting Custom Context

message = await bot.wait_for('friend_message')
ctx = await bot.get_context(message, cls=MyContext)
if ctx.valid:
    await bot.invoke(ctx)

Advanced Context Usage

Accessing View

The StringView used for parsing:

@bot.command()
async def viewinfo(ctx):
    view = ctx.view
    await ctx.send(f'Index: {view.index}')
    await ctx.send(f'EOF: {view.eof}')

Processing Commands Manually

@bot.event
async def event_friend_message(message):
    # Get context
    ctx = await bot.get_context(message)
    
    # Check if valid
    if not ctx.valid:
        return
    
    # Check if author is banned
    if ctx.author.id in banned_users:
        await message.reply('You are banned!')
        return
    
    # Invoke the command
    await bot.invoke(ctx)

Context in Error Handlers

@bot.event
async def event_command_error(ctx, error):
    # Access command that failed
    await ctx.send(f'Error in {ctx.command.name}!')
    
    # Access author
    await ctx.send(f'User: {ctx.author.display_name}')
    
    # Send error details
    if isinstance(error, commands.MissingRequiredArgument):
        await ctx.send(f'Missing: {error.param.name}')
    
    # Return False to print error
    return False

Example: Complete Usage

from rebootpy.ext import commands
import rebootpy

bot = commands.Bot(command_prefix='!', auth=auth)

@bot.command()
async def userinfo(ctx):
    """Display information about the command context."""
    
    # Basic info
    await ctx.send(f'Command: {ctx.command.name}')
    await ctx.send(f'Prefix: {ctx.prefix}')
    await ctx.send(f'Invoked with: {ctx.invoked_with}')
    
    # Author info
    await ctx.send(f'Author: {ctx.author.display_name}')
    await ctx.send(f'Author ID: {ctx.author.id}')
    
    # Context location
    if ctx.party:
        await ctx.send(f'Party: {ctx.party.id}')
        await ctx.send(f'Members: {len(ctx.party.members)}')
    else:
        await ctx.send('Location: DM')
    
    # Bot info
    await ctx.send(f'Bot: {ctx.bot.user.display_name}')
    await ctx.send(f'Total commands: {len(ctx.bot.commands)}')
    
    # Cog info
    if ctx.cog:
        await ctx.send(f'Cog: {ctx.cog.qualified_name}')

@bot.group(invoke_without_command=True)
async def admin(ctx):
    """Admin commands."""
    if ctx.invoked_subcommand is None:
        # Show available subcommands
        cmds = [c.name for c in ctx.command.commands]
        await ctx.send(f'Subcommands: {", ".join(cmds)}')

@admin.command()
async def reload(ctx, extension: str):
    """Reload an extension."""
    try:
        ctx.bot.reload_extension(extension)
        await ctx.send(f'Reloaded {extension}')
    except Exception as e:
        await ctx.send(f'Error: {e}')

@admin.command()
async def status(ctx):
    """Show bot status."""
    await ctx.send(f'Cogs: {len(ctx.bot.cogs)}')
    await ctx.send(f'Extensions: {len(ctx.bot.extensions)}')
    
    if ctx.party:
        await ctx.send(f'Party size: {len(ctx.party.members)}')

bot.run()

Best Practices

1. Use ctx.send() - Prefer ctx.send() over message.reply()
2. Check context - Verify ctx.party before accessing party properties
3. Access through context - Use ctx.bot, ctx.author instead of global variables
4. Helper methods - Add custom methods to context subclasses
5. Type hints - Use type hints for better IDE support
6. Error handling - Access context in error handlers for rich information

Next Steps

• Commands Extension - Learn about creating commands
• Cogs - Organize commands with cogs