Plan with ChatGPT. Build with Claude Code. Stop copy-pasting between them.
Sidekick is a desktop app for macOS and Windows that puts a ChatGPT conversation and a Claude Code terminal side by side, one pair per project. You think out loud with ChatGPT (by voice or text). When the plan is ready, ChatGPT writes a prompt for Claude, and one click hands it to Claude Code in your project folder. When Claude finishes, one more click sends a summary of what changed back to ChatGPT for review.
You decide every handoff. Nothing moves between ChatGPT and Claude unless you ask for it.
┌─────────────── ChatGPT ───────────────┐ ┌──────────── Claude Code ────────────┐
│ 1. You plan the change with ChatGPT. │ │ │
│ 2. ChatGPT writes a prompt for Claude.│──▶│ 3. Send to Claude: the prompt is │
│ │ │ pasted into Claude Code, which │
│ │ │ works in your project folder. │
│ 5. ChatGPT reviews the result and you │◀──│ 4. Send to ChatGPT: Claude's result │
│ decide what happens next. │ │ and a Git summary go back. │
└───────────────────────────────────────┘ └─────────────────────────────────────┘
- Projects as tabs. Each project has its own ChatGPT conversation, its own Claude Code session and its own folder. Switching tabs never mixes their context.
- One-click handoffs. Two round buttons on the divider: Send to Claude lights up when ChatGPT has written a Claude prompt; Send to ChatGPT appears when Claude has finished.
- Your Claude Code, unchanged. The right-hand pane is the real interactive
claudeterminal with your own settings, model, permissions and status line. You can type into it as usual. - Notifications. A badge, toast and system notification tell you when Claude finishes in a project you are not looking at.
- Voice-friendly. ChatGPT's voice mode works inside the app. Saying "send this to Claude" in your own message lets Sidekick send the next prompt after a 3-second countdown you can cancel (can be turned off in Settings).
Download the latest installer from Releases:
- macOS (Apple silicon or Intel):
Avva-Mobile-Sidekick-<version>-arm64.dmgor-x64.dmg - Windows (x64):
Avva-Mobile-Sidekick-Setup-<version>.exe(installs for your user only, no admin rights needed)
On first launch, a Before you start window checks your computer for what Sidekick needs and links to anything that is missing:
| Requirement | Why |
|---|---|
| Claude Code, installed and signed in | Writes the code in your project folder |
| A ChatGPT account | You sign in once inside the app |
| Git | Summarizes what Claude changed |
| Microphone permission (optional) | ChatGPT voice mode |
You can reopen this window any time from Help → Setup Checklist….
macOS builds are signed with Avva Mobile's Developer ID and notarized by Apple, so they open without warnings and update themselves. Windows builds are not code-signed yet: SmartScreen shows "unknown publisher"; choose More info → Run anyway.
Important
Security first. Sidekick sits between a website (ChatGPT) and a tool that can change files on your computer (Claude Code). It is built so that the website can never reach your computer, and nothing crosses between the two without you.
- The ChatGPT page runs in a sandboxed Chromium view with no Node.js access, context isolation on and no bridge of any kind to the app. It cannot read or write files, start processes, run Git or Claude, or call into Sidekick.
- It can only navigate to ChatGPT, OpenAI sign-in and the sign-in providers ChatGPT offers (Google, Apple, Microsoft). Any other link opens in your normal browser after the URL is checked.
- Downloads, USB/HID/serial/Bluetooth access and screen capture requests from the page are refused.
- The microphone is granted only to ChatGPT's own pages, only in the main frame, and only for audio. Sidekick never asks for it on its own at startup: on macOS the system asks once, when you click Allow in the setup window; on Windows, Windows' own microphone privacy setting applies.
- Text written by ChatGPT is treated as data. It never starts Claude by itself.
- Claude receives a prompt only when you click Send to Claude, or when your own ChatGPT message explicitly asks for it ("send this to Claude"). That automatic send waits 3 seconds with a Cancel button, never fires twice for the same message, and can be turned off.
- The prompt is cleaned of control characters before it is pasted, so text in a ChatGPT reply cannot type extra keys into Claude.
- A prompt that has already run successfully cannot be sent again by another click.
- Claude Code runs as your normal interactive session with your own permission settings. Sidekick never passes flags that skip Claude's permission prompts. Quitting while Claude is working asks for confirmation first.
Only when you click Send to ChatGPT, Sidekick posts a bounded review message into that project's ChatGPT conversation. It contains:
- an excerpt of the prompt and Claude's final answer,
- the Git branch, changed file names, diff statistics and a size-limited diff excerpt.
Files that look like secrets are left out of the diff: .env files, keys and certificates (*.pem, *.key, *.p12, *.pfx, SSH keys), anything named *secret* or *credential*, and lock files. The full Claude transcript is never sent.
Keep in mind that the diff excerpt is your source code going to ChatGPT. If a project's code must not leave your machine, do not use Send to ChatGPT for it.
- Sidekick never sees your ChatGPT password. You sign in on OpenAI's own page; the session cookie stays in the app's local Chromium profile, like in a browser.
- Claude Code keeps its own login. Sidekick never reads Claude's credentials; it only reads your default model name from
~/.claude/settings.jsonto show it in Settings. - Sidekick has no account, no server and no API keys of its own.
Sidekick itself makes exactly one kind of network request: checking this repository's GitHub Releases for updates (installed app only). Everything else on the network is the ChatGPT page you are using and Claude Code doing its own work. No analytics, no telemetry, no crash reporting.
| What | Where |
|---|---|
| Projects, layout, task history, settings | macOS: ~/Library/Application Support/AvvaMobile.Sidekick/ · Windows: %APPDATA%\AvvaMobile.Sidekick\ |
| ChatGPT sign-in (cookies) | Same folder, in the app's Chromium profile |
| Diagnostics log (app events, URLs with query strings removed) | …/AvvaMobile.Sidekick/diagnostics/events.log, never uploaded |
Deleting that folder resets the app and signs you out of ChatGPT inside it. Your project folders are never touched by Sidekick itself; only Claude Code changes files, under its own permissions.
Installed apps check for a new version on launch and every 4 hours, download it in the background and ask before restarting. Updates come only from this repository's GitHub Releases, built by the public release workflow from tagged source. The packaged app has Electron's Node.js and debugger entry points switched off (Electron fuses), so it cannot be run as a plain Node.js runtime.
Please report security issues privately through GitHub: Security → Report a vulnerability on this repository. Do not open a public issue for them. Details, supported versions and scope: .github/SECURITY.md.
- ChatGPT's page changes often. If Send to Claude stays disabled while a prompt is visible, the prompt detection needs an update.
- Windows support is new and has had little real-world testing.
- Windows builds are not yet code-signed (see Install).
npm install
npm run app # build and launch (macOS dev bundle with the product name and icon)
npm test # unit tests
npm run typecheck
npm run dist:mac # local macOS build into dist/
npm run dist:win # local Windows build into dist/Requires Node.js 22.12 or later. Release steps: docs/RELEASING.md. Architecture, workflow and security requirements: docs/ARCHITECTURE.md, docs/WORKFLOW.md, docs/SECURITY.md. Decisions are recorded in docs/DECISIONS.md.
MIT © 2026 Avva Mobile