From ccds-mobile
Offline storage, sync, and conflict-resolution specialist for mobile. Auto-invoked when local persistence (SQLite, Core Data, Room), sync engines, background sync, or conflict resolution is being built.
How this skill is triggered — by the user, by Claude, or both
Slash command
/ccds-mobile:mobile-offline-syncThe summary Claude sees in its skill listing — used to decide when to auto-load this skill
The app must work on the subway and reconcile correctly when it comes back
The app must work on the subway and reconcile correctly when it comes back online. Sync bugs corrupt user data — the one class of mobile bug an update cannot retroactively fix.
BGAppRefreshTask (short, ~30 s budget) / BGProcessingTask on
iOS. Hand-rolled background loops get killed and drain battery.| Entity shape | Policy | Why |
|---|---|---|
| Single-owner record (settings, drafts) | last-write-wins on a server timestamp | conflicts are self-conflicts; latest intent wins |
| Independent fields on one record | per-field LWW (merge field-wise) | two devices editing different fields shouldn't clobber each other |
| Collaborative text / ordered lists | CRDT or OT library — don't hand-roll | character-level merge is a research problem, not a sprint task |
| Money, inventory, counters | server-authoritative; client sends operations (+1), not states (=5) | replayed state writes corrupt totals |
| True business conflict (double-booking) | surface to the user | silently picking a side is data loss with extra steps |
Adversarial tests that must exist: kill the app mid-sync, replay the same outbox batch twice, edit the same record on two offline devices, downgrade the app with a non-empty outbox, sync 10k changes on a flaky connection.
Reachability/ConnectivityManager "online" as truth; the only real
connectivity test is the request succeedingRelated: mobile-perf (sync work off the main thread), mobile-platform
(background execution limits), mobile-crash (mid-sync crash recovery) ·
domain agent: mobile-architect (offline posture) · output/ADR format:
playbook-conventions
Provides UI/UX resources: 50+ styles, color palettes, font pairings, guidelines, charts for web/mobile across React, Next.js, Vue, Svelte, Tailwind, React Native, Flutter. Aids planning, building, reviewing interfaces.
Fetches up-to-date documentation from Context7 for libraries and frameworks like React, Next.js, Prisma. Use for setup questions, API references, and code examples.
npx claudepluginhub ggrace519/claude-code-dev-studio --plugin ccds-mobile