Anthropic, the company behind the AI-powered coding assistant Claude Code, has introduced a new feature called **mods**. These are described as "small TypeScript features that modify how Claude Code functions and behaves." The company announced the update on Thursday, October 1st, explaining that mods allow developers to customize the assistant's behavior and interface. They can be used in both the command-line interface (CLI) and the desktop application. Mods work by hooking into events that occur during every action Claude Code performs, such as calling a tool, requesting permission, or displaying part of the screen. A mod can intervene before, during, or after these actions. For example, it might rewrite a prompt, block or modify a tool call, accept or reject a permission request, or edit or replace parts of the interface. This gives developers more control over Claude Code without waiting for new features to be officially released by Anthropic. According to Anthropic, while previous tools called "hooks" allowed some customization, they had limitations. Hooks could not fully rewrite events, draw new interfaces, or replace features—tasks that mods now enable. Developers can create mods using Claude itself, which handles writing the TypeScript code, installing it, and reloading the session. A dedicated page on Anthropic’s website provides a step-by-step guide for building a mod. Some of Claude Code's native features have already been converted into mods. For example, the /diff command, which compares code changes, is now a mod that can be disabled or replaced with a custom version. Anthropic plans to gradually convert more native features into mods, allowing users to reduce Claude Code to a minimal core and add only the components they need. Mods require version 2.1.287 of Claude Code or newer and are enabled by default. They can be found in the Claude directory or accessed via the /plugin command in the CLI. To share a mod, it must be packaged into a plugin and submitted to the directory. Anthropic warns that mods have "the same access to the machine as Claude Code" and are not run in a sandboxed environment, recommending that users only install mods from trusted sources.