Fracture

An MCP (Model Context Protocol) server that provides Discord tools. Built with the MCP Ruby SDK and discordrb.

Requirements

• Ruby 4.0+
• A Discord bot token (create one here)

Installation

git clone https://github.com/yourusername/fracture.git
cd fracture
bundle install

Configuration

Set your Discord bot token as an environment variable:

export DISCORD_BOT_TOKEN=your_token_here

Claude Desktop

Add to your Claude Desktop MCP config (claude_desktop_config.json):

{
  "mcpServers": {
    "fracture": {
      "command": "ruby",
      "args": ["/path/to/fracture/fracture.rb"],
      "env": {
        "DISCORD_BOT_TOKEN": "your_token_here"
      }
    }
  }
}

On Windows, you may also need to set DISCORDRB_NONACL=1 in the env block.

Usage

Run the server directly over stdio:

ruby fracture.rb

The server communicates via stdin/stdout using the MCP JSON-RPC protocol.

Tools

Guilds

Tool	Description	Arguments
get_guilds	Lists all guilds (servers) the bot is a member of. Returns each guild's ID and name.	None
get_guild	Gets detailed information about a specific guild, including its categories, channels, and members. For guilds with fewer than 100 members, full member details are returned; otherwise only the member count is included.	guild_id (string, required)
get_guild_members	Lists all members of a guild. Reserved for large servers with more than 100 members. Returns each member's ID, username, and display name.	guild_id (string, required)

Bans

Tool	Description	Arguments
ban_user	Bans a user from a guild.	guild_id (string, required), user_id (string, required), reason (string, required)
unban_user	Unbans a user from a guild.	guild_id (string, required), user_id (string, required), reason (string, required)
get_guild_bans	Lists all bans for a guild. Returns each ban's user ID and reason.	guild_id (string, required)

Members

Tool	Description	Arguments
get_member	Gets detailed information about a guild member, including their roles, status, join date, voice state, and more.	guild_id (string, required), member_id (string, required)
add_role	Adds a role to a guild member.	guild_id (string, required), member_id (string, required), role_id (string, required)
remove_role	Removes a role from a guild member.	guild_id (string, required), member_id (string, required), role_id (string, required)

Messages

Tool	Description	Arguments
send_message	Sends a message to a channel or user via DM. Specify either guild_id + channel_id for a channel message, or user_id for a DM. At least one of content or attachments must be provided.	guild_id (string, optional), channel_id (string, optional), user_id (string, optional), content (string, optional), attachments (string[], optional)
edit_message	Edits an existing message in a channel or DM.	message_id (string, required), content (string, required), guild_id (string, optional), channel_id (string, optional), user_id (string, optional)
delete_message	Deletes a message from a channel or DM.	message_id (string, required), guild_id (string, optional), channel_id (string, optional), user_id (string, optional)

Roles

Tool	Description	Arguments
get_guild_roles	Gets all roles for a guild, including decoded permissions for each role.	guild_id (string, required)
create_role	Creates a new role in a guild.	guild_id (string, required), name (string, required), colour (integer, optional), hoist (boolean, optional), mentionable (boolean, optional), permissions (string[], optional)
delete_role	Deletes a role from a guild.	guild_id (string, required), role_id (string, required)

Categories

Tool	Description	Arguments
get_categories	Gets all categories for a guild, including their channels and permission overwrites.	guild_id (string, required)
create_category	Creates a new category in a guild.	guild_id (string, required), name (string, required), position (integer, required)
edit_category	Edits a category's name and/or position. At least one of name or position should be provided.	guild_id (string, required), category_id (string, required), name (string, optional), position (integer, optional)
delete_category	Deletes a category from a guild.	guild_id (string, required), category_id (string, required)

Channels

Tool	Description	Arguments
create_channel	Creates a new text channel in a guild, optionally under a category.	guild_id (string, required), name (string, required), category_id (string, optional)
read_channel	Reads messages from a channel. Returns messages with author info, content, attachments, and timestamps.	guild_id (string, required), channel_id (string, required), limit (integer, optional — default 100, max 100), offset (integer, optional — default 0)
rename_channel	Renames a channel in a guild.	guild_id (string, required), channel_id (string, required), name (string, required)
delete_channel	Deletes a channel from a guild.	guild_id (string, required), channel_id (string, required)

Permissions

Tool	Description	Arguments
define_overwrite	Defines a permission overwrite for a role or user on a channel or category. The type determines the target: role, channel, category, or user. The target_id is the complementary target (e.g., if type is role, target_id is the channel or category).	guild_id (string, required), type (string, required — one of role, channel, category, user), id (string, required), target_id (string, required), allowed (string[], required), denied (string[], required), reason (string, required)

Available Permissions

create_instant_invite, kick_members, ban_members, administrator, manage_channels, manage_server, add_reactions, view_audit_log, priority_speaker, stream, read_messages, send_messages, send_tts_messages, manage_messages, embed_links, attach_files, read_message_history, mention_everyone, use_external_emoji, view_server_insights, connect, speak, mute_members, deafen_members, move_members, use_voice_activity, change_nickname, manage_nicknames, manage_roles, manage_webhooks, manage_emojis

Development

# Run tests
bundle exec rspec

# Run linter
bundle exec rubocop

License

MIT