Add custom tools to Claude Code with YAML (no MCP required) (github.com)

Claude Code has introduced a new feature allowing users to add custom tools via simple YAML definitions, significantly simplifying the process of extending functionality without the need for complex setups or MCP servers. Users can create tools, such as a Slack notification system or a dice roller for games like D&D, with just a few commands. The integration requires minimal steps: cloning a repository, running an installation command, and starting an extension proxy to intercept API requests, making the tools appear as built-in to Claude Code while executing locally on the user's machine. This innovation is particularly significant for the AI/ML community as it democratizes the creation of tailored applications, enabling developers to swiftly implement custom functionalities for specific use cases. The ease of use reflects a shift towards more accessible AI development, where users can focus on practical applications without deep technical knowledge of existing frameworks. By lowering barriers to customization, this feature encourages experimentation and rapid prototyping, allowing developers to enhance their interactions with AI systems efficiently.