Skill: Flatpak Packaging

Manifest (org.example.MyApp.json, repo root)

{
  "id": "org.example.MyApp",
  "runtime": "org.gnome.Platform",
  "runtime-version": "48",
  "sdk": "org.gnome.Sdk",
  "command": "myapp",
  "finish-args": [
    "--share=ipc",
    "--socket=fallback-x11",
    "--socket=wayland",
    "--device=dri"
  ],
  "cleanup": ["/include", "/lib/pkgconfig", "*.la", "*.a"],
  "modules": [
    {
      "name": "blueprint-compiler",
      "buildsystem": "meson",
      "cleanup": ["*"],
      "sources": [{
        "type": "git",
        "url": "https://gitlab.gnome.org/GNOME/blueprint-compiler.git",
        "tag": "v0.18.0"
      }]
    },
    {
      "name": "myapp",
      "buildsystem": "meson",
      "sources": [{ "type": "dir", "path": "." }]
    }
  ]
}

Rust apps add "build-options": {"append-path": "/usr/lib/sdk/rust-stable/bin"} and sdk-extension org.freedesktop.Sdk.Extension.rust-stable; use flatpak-cargo-generator for offline crate sources on Flathub.

Permissions — request the minimum

Need	finish-arg
GUI (always)	--share=ipc --socket=fallback-x11 --socket=wayland --device=dri
Network	--share=network
User files (avoid — prefer FileChooser portal, which needs nothing)	--filesystem=home (Flathub will question it)
Specific dir	--filesystem=xdg-music:ro
Sound	--socket=pulseaudio
Notifications, opening URIs, screenshots…	nothing — use portals

Settings persist automatically (GSettings works in the sandbox via dconf portal).

Build & run loop

flatpak install -y flathub org.gnome.Platform//48 org.gnome.Sdk//48
flatpak-builder --user --install --force-clean build-dir org.example.MyApp.json
flatpak run org.example.MyApp
# Poke inside the sandbox:
flatpak run --command=sh --devel org.example.MyApp

Flathub submission checklist

• App ID matches a domain you control (or io.github.<user>.<repo>)
• Metainfo passes appstreamcli validate and flatpak run --command=flatpak-builder-lint org.flatpak.Builder manifest <file>
• Screenshots (16:9-ish, light theme) + <content_rating> in metainfo
• Icon: SVG at 128px nominal, plus symbolic
• Desktop file: Exec, Icon=<app-id>, Categories, StartupNotify=true
• No broad --filesystem unless genuinely required (justify in PR)
• Sources pinned (tags/commits, not branches)
• Fork flathub/flathub, add manifest, open PR against new-pr branch

Related: skills/language-quickstart/SKILL.md (per-language manifests), skills/about-dialog/SKILL.md (metainfo).