Restore a self-hosted flashcard collection’s mobile synchronization

Why use this

1. A learner with a self-hosted flashcard collection may find that desktop and phone data stop agreeing after a service or database change. Repairing synchronization without protecting the collection can put cards and review history at risk.

2. This job could organize the failure evidence and propose a reversible recovery path before any service or schema change. Distinguishing connectivity, compatibility and collection integrity helps the owner avoid treating one successful connection as proof that synchronization is restored.

Why an agent / simpler alternative

Useful judgment

Classify sync symptoms, compare version/schema evidence and identify what must be preserved before a repair.

Simpler alternative

Use the application's supported sync service when self-hosting is unnecessary or maintenance resources are limited.

Unsuitable when

There is no verified backup or the repair requires destructive database changes without explicit authorization.

Proposed inputs

1. Name

   Sync diagnostics

   Owner

   Collection owner

   Minimum scope

   Redacted error messages, versions and relevant service state

   Quality check

   Exclude credentials and preserve exact error context

2. Name

   Collection inventory

   Owner

   Owner

   Minimum scope

   Copies/backup status, card counts and review-history expectations

   Quality check

   Distinguish newest authoritative collection from stale replicas

Access and setup — proposed or unknown

Proposed minimum

1. Begin with synthetic logs and a recovery checklist; no server access, database queries, deployment or phone sync.

Compatibility unknowns

1. Current application/schema versions, sync compatibility, backup integrity and runtime support are unknown.

External actions requiring approval

1. Server changes, credential setup, database migration, overwrites and synchronization of private content require authorization.

Expected deliverable and review checks

Proposed artifact

Diagnosis proposal with version comparison, backup prerequisites, rollback boundaries and unexecuted integrity checks.

Critical checks

1. Preserve originals and review history; identify the authoritative copy; separate service reachability from complete collection transfer.

Missing output evidence

This overlay adds no new output inspection, execution or validation; consult the referenced canonical source outcome limits.

Failure signals and proposed responses

1. Signal

   A stale phone copy overwrites newer cards

   Why it matters

   Restoring connection can cause data loss

   Proposed response

   Define direction and conflict handling before any sync.

2. Signal

   A schema repair changes unsupported fields

   Why it matters

   The service may work while data semantics break

   Proposed response

   Require version-specific evidence and a reversible copy-based approach.

Effort and cost — unknown

Setup work

1. Inventory versions, replicas and recoverable backups.

Ongoing review

1. Owner verifies cards and review history after any separately approved repair.

Unknowns

1. Schema behavior, backup recoverability, repair effort and hosting costs are unknown.

First check — proposed, unexecuted

Status

proposed_unexecuted

Synthetic fixture

Invent desktop/phone inventories with different update dates and a schema-error log; draft a recovery plan only.

Acceptance checks

1. Identify stale-copy risk; require a preserved backup; separate connection and integrity checks; execute nothing.

Stop conditions

1. Stop if authoritative data or a safe rollback path is unresolved.

Limits

1. A recovery plan cannot establish collection integrity, successful synchronization or safe database compatibility.