Snap-O is a fast, tidy macOS app for Android inspection. Originally built for streamlined screen capture, Snap-O now also supports network traffic inspection and live UI adjustments on Android devices and emulators.

It runs on macOS 15 or later and requires adb from the Android Platform Tools.

Network Inspector

Curious about mirroring app traffic into the macOS client? Check the Network Inspector guide for setup steps, dependency coordinates, and configuration tips.

Snap-O can replay network requests that happened before you opened Snap-O, so you do not miss early events, and includes collapsible JSON pretty printing.

Screen Capture

• Shows a screenshot the moment the window opens
• Instantly preview screen recordings, and step through frame-by-frame.
• Lets you drag and drop captures anywhere without saving them first
• Multi-device support
• Supports multiple windows of captures at once
• Keeps your disk uncluttered by cleaning up after itself
• Integrates with Android Studio External Tools

Tweaks (Alpha)

Snap-O Tweaks lets you inspect and adjust Jetpack Compose UI values without rebuilding or restarting your app. Tweaks is an alpha feature; its APIs, behavior, and interface may change.

Follow the Tweaks developer guide for setup steps.

Why build an Android inspection system?

Capturing visuals and validating traffic for teammates or pull requests adds many small paper cuts. You might like Snap-O if you've ever wished you could:

• Share screenshots and recordings without littering your disk with throwaway files
• Preview a recording instantly without saving it first
• Scrub frame by frame to confirm an animation behaves as expected
• Use something that feels faster than the default capture tools

I've built variations of this tool a few times over the last decade; this is the first one I'm open-sourcing.

Usage

1. Connect an Android device with USB debugging enabled or start an emulator
2. Launch Snap-O
3. Enjoy the immediate screenshot
4. ⌘R to refresh the screenshot. ⇧⌘R to start a screen recording.

ADB Selection (optional)

Snap-O talks to the ADB server directly without running adb.

If the ADB server is not running, Snap-O asks you to pick your adb binary so it can restart the server for you.

Note: Snap‑O uses the macOS Hardened Runtime. It will run the adb binary you select, so always choose a trusted adb from the official Android Platform Tools.

Previously adjusted Tweaks

Include previously adjusted values even after their declarations leave composition:

snapo tweaks list --all -s <serial> -n <socket> --json
snapo tweaks get 'Motion/Duration' --all -s <serial> -n <socket> --json

The equivalent API is GET /tweaks?include=adjusted. Inactive tweaks remain read-only. See the Tweaks protocol guide for descriptors and updates.

Drag and Drop

After you capture a screenshot or screen recording, you can drag and drop it without saving first. Drop the capture straight into a GitHub pull request, a Slack message, or any app that accepts images and video.

Keyboard Shortcuts

Action	Shortcut
New screenshot	⌘R
Start recording	⇧⌘R
Start live preview	⇧⌘L
Stop recording / preview	⎋
Save as	⌘S
Copy image to clipboard	⌘C
Previous device	⌘[
Next device	⌘]
Show / hide App Inspector	⌥⌘I
Show / hide Capture	⌥⌘C

Android Studio External Tools

Use Android Studio’s External Tools to trigger Snap-O directly from the IDE.

1. In Android Studio, open Settings → Tools → External Tools (or Preferences on macOS).
2. Click + and add a new tool named "Snap-O Screenshot".
   • Program: open
   • Arguments: snapo://capture
3. Repeat to add "Snap-O Recording" with the same Program and the Arguments snapo://record.
4. The new tools appear under Tools → External Tools.
5. Assign keymap shortcuts if you like, e.g. ⇧⌘S to activate a screenshot.

Running these tools launches Snap-O (or brings it to the foreground) and immediately starts a capture or recording.

There is currently no support for choosing a specific device/emulator when starting Snap-O in this way.

Command Line Inspector

Snap-O bundles a small Python command-line client at:

/Applications/Snap-O.app/Contents/MacOS/snapo

It uses the host computer's configured adb command, requires Python 3, and does not require the Snap-O app to be running.

snapo network list --json
snapo network requests -s <serial> -n <socket> --no-stream --json
snapo network show -s <serial> -n <socket> -r <request-id> --json
snapo tweaks apps --json
snapo tweaks list -s <serial> -n <socket> --json
snapo tweaks set 'Typography/Font size' 42 -s <serial> -n <socket> --json
snapo tweaks reset 'Typography/Font size' -s <serial> -n <socket> --json

Why a web UI for the App Inspector?

The Network and Tweaks inspectors share a React UI hosted in the macOS app's system WebKit runtime. Native Swift code handles ADB and transport through the host computer's existing ADB server, so the distribution does not include Chromium, Node.js, or another ADB executable. The same UI can also run in a browser through its HTTP transport.

The screenshot tool remains in SwiftUI because it delivers a better macOS experience for video playback today. Snap-O uses AVKit because it gives a polished video player on macOS and keeps the download small. VLC-based playback felt clunky and the viewing experience suffered.

Alternatives

Snap-O currently has only basic "Live Preview" support.

For a more feature-rich live preview, take a look at scrcpy.

Project status

Snap-O is a small side project kept alive when time allows. If it works for you, great! If it doesn't, feel free to open an issue or fork it to fit your needs.

Building from source

The macOS app requires Xcode 26 or later and Node.js 22.12 or later.

1. Install the Android Platform Tools (via Android Studio or brew install android-platform-tools).
2. Install Node.js 22.12 or later and ensure npm is available to Xcode.
3. Open snapo-app-mac/Snap-O.xcodeproj in Xcode.
4. Build and run.

Notarizing or shipping builds

If you need to notarize the app yourself:

1. Copy snapo-app-mac/Config/Signing.xcconfig.sample → snapo-app-mac/Config/Signing.xcconfig.
2. Edit the new file with your Apple Developer Team ID and signing certificate name.
3. Use Xcode's Product → Archive flow, then distribute or upload as usual. The file is ignored by Git, so your credentials remain private.

Codex Plugin

Snap-O includes a Codex plugin for macOS and Linux. It bundles skills for network inspection and live Tweaks, along with their shared Python CLI, and requires Python 3 and Android Platform Tools.

Add the Snap-O marketplace and install the plugin:

codex plugin marketplace add openai/snap-o --ref main
codex plugin add snap-o@snap-o

If you previously installed this marketplace with sparse paths, migrate once:

codex plugin marketplace remove snap-o
codex plugin marketplace add openai/snap-o --ref main
codex plugin add snap-o@snap-o

Refresh the marketplace and reinstall the plugin to pick up updates:

codex plugin marketplace upgrade snap-o
codex plugin add snap-o@snap-o

Start a new Codex session after installing or updating the plugin.

Linux Support

You can inspect network requests and alpha Tweaks from Snap-O on a Linux machine by using the dependency-free snapo Python CLI tool. Install Python 3 and Android Platform Tools, then download the script from the main branch and put it on PATH:

mkdir -p ~/.local/bin
curl -fsSL https://raw.githubusercontent.com/openai/snap-o/main/scripts/snapo -o ~/.local/bin/snapo
chmod +x ~/.local/bin/snapo

This is the same CLI shipped as part of the macOS app at Snap-O.app/Contents/MacOS/snapo.

The script supports snapo network list, requests, and show, as well as snapo tweaks apps, list, get, set, reset, and watch. It resolves adb from PATH, ANDROID_SDK_ROOT, or ANDROID_HOME; use --adb <path> or SNAPO_ADB to select a specific ADB executable or wrapper. By default, server selection is left to the configured ADB command, which normally connects to 127.0.0.1:5037. Pass --adb-host <host> --adb-port <port> to use an explicit remote ADB server.

Verify that ADB can see your Android device, then inspect its available Snap-O servers:

adb devices -l
snapo network list --json
snapo tweaks apps --json

With the default ADB configuration, the CLI opens a localhost forward for the selected snapo_network_<pid> or snapo_tweaks_<pid> socket and removes it when the command exits. Wrappers selecting a remote ADB server must tunnel that forward back to localhost; otherwise, specify --adb-host and --adb-port. With an explicit ADB endpoint, the CLI connects through the ADB server directly and does not create a forward. Treat captured bodies, URL query values, and editable tweaks as sensitive.

Community

Bug reports and small patches are welcome, but there is no formal roadmap. If you do decide to contribute, please take a quick look at CONTRIBUTING.md and the CODE_OF_CONDUCT.md.

License

This project is licensed under the Apache License 2.0, Copyright 2025 OpenAI. See the LICENSE file for details.