iOS

Put one pack on the pasteboard, then open Buzzio. Apple usually rejects apps whose only job is exporting stickers — ship real functionality.

Open Buzzio

let data = try JSONSerialization.data(withJSONObject: pack, options: [])
UIPasteboard.general.setItems(
    [["dev.buzzio.third-party.sticker-pack": data]],
    options: [.expirationDate: Date().addingTimeInterval(60)]
)
UIApplication.shared.open(URL(string: "buzzio://stickerPack")!)

Can open?

<key>LSApplicationQueriesSchemes</key>
<array>
    <string>buzzio</string>
</array>

Pasteboard JSON

One pack per open. tray_image is PNG base64. Each sticker image_data is WebP base64.

{
  "identifier": "cuppy",
  "name": "Cuppy",
  "publisher": "Example",
  "tray_image": "<base64 PNG>",
  "ios_app_store_link": "",
  "android_play_store_link": "",
  "stickers": [
    {
      "image_data": "<base64 WebP>",
      "emojis": ["🙂"],
      "accessibility_text": "A round smiling face"
    }
  ]
}

Art limits are the same as Android. See the spec.