# Diff Viewer

> A code diff that streams in as an agent writes the patch, then a per hunk review: accept or reject each change, fold what is done, and switch between unified and split views with word level highlights.

- Author: [Aadi](https://21st.dev/@aadixc0de)
- Library: [chatcn](https://21st.dev/@aadixc0de/library/chatcn)
- License: mit
- Tags: Agent, Diff, Devtool, Code Review
- npm dependencies: @base-ui/react
- Live preview: https://21st.dev/@aadixc0de/components/diff-viewer

## Install

```bash
npx shadcn@latest add "https://21st.dev/r/aadixc0de/diff-viewer?api_key=$API_KEY_21ST"
```

Requires a 21st API key (generate one at https://21st.dev/mcp) passed as `API_KEY_21ST`. Free accounts get a limited number of installs per day; unlimited on a paid plan — see https://21st.dev/pricing.

Full component directory: https://21st.dev/llms.txt · More like this: https://21st.dev/community/components/s/agent.md