Here's the current up-to-date list. Markdown file included. You can keep yourself updated at the Claude official site.
Claude Code Commands Reference
Commands control Claude Code from inside a session. They provide a quick way to switch models, manage permissions, clear context, run a workflow, and more.
Type / to see every command available to you, or type / followed by letters to filter. A command is only recognized at the start of your message. Text that follows the command name is passed to it as arguments.