Updates

Updates

Contained has two update systems: Sparkle app updates and registry image update checks.

App updates

Signed distribution builds use Sparkle. Development bundles are inert until a signed build points at a published appcast feed.

Channels are selected in Settings → Updates:

Channel	Feed
Stable	stable/appcast.xml
Beta	beta/appcast.xml
Nightly	nightly/appcast.xml

Each appcast lives at the root of its branch and is served by raw.githubusercontent.com. The selected feed is the channel, so appcast items do not need Sparkle channel tags.

The Nightly feed is intentionally a superset: it contains nightly builds plus promoted Beta and Stable appcast items. Sparkle orders them by CFBundleVersion, so release workflows retain the same build number when a commit moves between Nightly, Beta, and Stable.

Release workflows only commit root appcast.xml back to channel branches. Those appcast-only commits are path-ignored and marked [skip ci] to avoid release loops.

CI validates generated appcasts before those commits. The validator requires a numeric Sparkle build number, a short version, an enclosure URL, and embedded or linked release notes. Stable feeds reject Beta/Nightly short versions, Beta feeds require Beta short versions, and Nightly feeds allow all three channels because Nightly users should receive promoted builds without switching channels.

Fresh installs default to Nightly during pre-1.0 development.

Release notes

Release notes are generated from full release notes plus channel/build changes. By default both come from CHANGELOG.md; RELEASE_NOTES.md, CHANGES.md, and CHANGES_DIR are supported when maintainers want split sources. The release scripts embed the composed notes into Sparkle appcasts, and the bundled in-app What's New view uses the same order:

• channel/build changes first, when the channel has them
• full version notes second

Generated notes follow the channel:

• Stable: Full Release Notes.
• Beta: Changes Since Last Beta plus Full Release Notes.
• Nightly: Changes Since Last Nightly plus Full Release Notes.

scripts/ci-validate.sh checks that ordering before CI builds, and scripts/sync-changelog-resource.sh --check fails when the bundled in-app changelog resource has drifted from the root CHANGELOG.md. PR CI also requires material source/script/workflow changes to include a release note or change fragment unless the PR is explicitly labeled no-release-note.

Image updates

Image update checks compare local image digests with remote registry digests. Results are stored locally and surface on image cards, container cards, toolbar panels, palette results, and System.

Manual checks are available from Images, System, toolbar actions, and the command palette. Background check cadence is set in Settings → Updates → Image updates.