Goldie: App Store screenshot generator for coding agents (and humans)

goldie makes App Store and Google Play screenshots, and App Store preview videos, for a mobile app. argent replays flows on an iOS simulator or an Android emulator. goldie frames the captures with a device bezel, a background and a headline. It joins the clips into a preview video. It checks the result against the upload rules of the stores.

goldie is framework agnostic. It drives the app through the simulator or the emulator. It works the same for SwiftUI, UIKit, Jetpack Compose, Flutter, React Native and Kotlin Multiplatform apps.

Install

You need Node 20 or newer and ffmpeg on the PATH. App Store screenshots need macOS with iOS simulators (Xcode). Google Play screenshots need an Android emulator, which works on macOS, Linux and Windows. On Linux, argent needs a few extra packages for Android emulators. On a Linux or Windows machine keep only pixel-10-pro in devices; goldie doctor says so when an iOS device is configured on a host that cannot run it.

Install the CLI:

npm i -g goldie

Add the skill to your coding agent:

npx skills add kacperkapusciak/goldie            # Cursor, Codex, any agent

/plugin marketplace add kacperkapusciak/goldie   # Claude Code
/plugin install goldie@goldie

The skill works with all agents that support the skills format.

Use with a coding agent

Ask from your app repo:

create app store screenshots using goldie

The agent asks which stores to target. It explores the app, writes the flows and the config, and opens the studio. Follow-ups such as use a dark background edit the same files.

Use by hand

Copy goldie.config.example.ts to goldie.config.ts. Point its scenes at argent flows in .argent/flows. Then run:

goldie doctor     Check tools, simulators and flows
goldie all        Capture, frame, render the preview and verify
goldie studio     Preview and tweak the assets in the browser

The output goes to out/screenshots/// and out/previews///. The iPhone gets 1320 x 2868 screenshots and an 886 x 1920 H.264 preview. Google Play gets 1080 x 1920 screenshots. A preview must run 15 to 30 seconds. Add "ipad-13" to devices for 13" iPad screenshots (2064 x 2752) and a 1200 x 1600 preview from the same flows, each device with its own bezels, captures and output folder.

Every locale renders from one capture run in the first locale, which suits apps whose screens look the same in every language. Set localizedCaptures: true to capture each locale in its own language instead: capture replays the flows once per locale with the simulator pinned to it, into out/raw///, and each locale's screenshots, preview and studio view use its own captures. It applies to iOS devices; Android emulators keep one shared capture.

Google Play

The pixel-10-pro device key renders Google Play phone screenshots (1080 x 1920) from the same scenes. The example config already lists this key. Remove it from devices for an iOS-only run. Argent flows also replay on Android, so the scene flows are shared. A flow works on both platforms when its selectors match. The captures come from an Android emulator. Its AVD must use the Pixel 10 Pro or the Pixel 9 Pro hardware profile (both have a 1280 x 2856 screen). goldie reuses a running emulator that matches, or boots the AVD itself. Create the AVD from either device definition (Android Studio > Device Manager). Then add the build to the config:

devices: ["iphone-6.9", "pixel-10-pro"],
android: {
  appPath: "/path/to/app-release.apk",
  applicationId: "com.example.app",
},

goldie frames Android tiles with the bundled Pixel 10 Pro bezel. The frame variant is iPhone art, so it does not apply to them. android.frame swaps in your own art and its geometry. The Play Store promo video is a YouTube link, so preview and all record the preview scene on the emulator and render a portrait video for you to post on YouTube yourself. Apple's 15-30 second window does not apply to it.

Design

https://github.com/user-attachments/assets/d6171a90-8fc1-437b-a574-5a8547068a3c

The studio switches devices, backgrounds, templates, bezel, fonts and per-tile copy. It saves the choices to goldie.design.json, so the CLI renders the same result. The config also takes:

frame: 17-pro-blue, 17-pro-silver, 17-pro-orange for the iPhone, ipad-pro-13-silver, ipad-pro-13-space-gray for the iPad (one variant, or one per device key), or a custom bezel image; theme.screenOnly: true removes it.
theme.template: editorial, showcase, magazine, storyboard, dynamic, or your own layout sequence from classic, copy-below, hero, offset, tilt, tilt-right, duo, duo-tilt, panorama, panorama-duo, minimal.
theme.fontFamily: a CSS font stack. Merriweather, DM Mono, Lato, DM Sans, Montserrat, Noto Sans SC (Simplified Chinese) and Noto Sans Arabic are bundled; the two Noto faces are also appended to every stack as a per-glyph fallback, so Chinese and Arabic copy draws whatever font you name.
theme.fontFiles: typefaces of your own, registered alongside the bundled ones so fontFamily can name them. Needed for a brand font, and for any script the bundled families do not cover - the copy is drawn with skia, not a browser, so an unregistered family exports as tofu boxes rather than falling back. Paths are relative to the config.
```
fontFiles: [
  { family: "Zain", files: { 400: "../assets/fonts/Zain-Regular.ttf",
                             700: "../assets/fonts/Zain-Bold.ttf" } },
],
fontFamily: "Zain",
```
decorations: badges or images layered behind the device.

Remarks

Use a Release build. Debug builds paint LogBox banners into the captures.
Flows fail when the app changes. Ask the coding agent to repair them, or re-record them with argent.

goldie