Sidecar

A companion window for Claude Code.

Sidecar sits next to Claude Code and follows the conversation you're in. You review what Claude changed, line by line, and when you comment on a page it built, the comment lands back in the conversation.

Review, comment, undo.

Each one as it looks in the window.

Review

Approve or reject a line, a hunk, a file or a whole folder. Claude hears about every reject, and ⌘Z takes back your last 50 decisions.

Comments

Select anything on a page Claude built and leave a note. Send it, and it reaches the conversation as your own message.

Follows you

Switch terminal tab or start typing in another session, and Sidecar moves there with you.

What the file held before

A hook keeps it before Claude's first edit, so every change can be undone.

app/pages/index.vue

148 <section class="line wrap" aria-labelledby="line-title">
149 − <h2 id="line-title" class="heading">One rule runs through all three.</h2>
153 </SiteMount>
154 − <p class="small">A toy version that matches words. Sage and AI Shell ask a separate model to rate every step, never the one that wrote it.</p>
173 <h2 id="standard-title" v-enter.words class="heading">How I work</h2>
148 <section class="line wrap" aria-labelledby="line-title">
149 + <h2 id="line-title" v-enter.words class="heading">One rule runs through all three.</h2>
153 </SiteMount>
154 + <p v-enter class="small">A toy version that matches words. Sage and AI Shell ask a separate model to rate every step, never the one that wrote it.</p>
173 <h2 id="standard-title" v-enter.words class="heading">How I work</h2>
174 + <p v-enter class="body">Agents write a lot of my code. I wrote the rules they work under, I review what they ship, and nothing goes out under my name that I can't explain.</p>
175 + <span v-enter.line class="rule" aria-hidden="true" />

The numbers

  • 50 decisions back
  • 1 copy before the first edit
  • 4 grains: line, hunk, file, folder
  • 1 s to follow your tab

Questions

Does it touch my files?

It keeps what a file held before Claude's first edit, so every change can be read and undone.

How far back?

Fifty decisions.

Does it follow me?

Start typing in another session or switch tab and it moves there with you.

Where does a note go?

Into the conversation, as your own message.

Built with

Nuxt and a small local server, wired into Claude Code through hooks. Before Claude's first edit to a file, a hook keeps what the file held, so every change can be reviewed and undone.

  • Nuxt
  • Claude Code hooks

Next

Sage

A Mac assistant in the notch. Hold a key, say what you want in English, Italian or Chinese, and it does the steps, asking before anything it can't undo.

See Sage