MongoDB Realm Mobile Sync

Parent: MongoDB Atlas · researched 2026-05-28T15:31:42.794Z· 0 sources · 11 concepts · skill mongodb-realm-mobile-sync

> CRITICAL: Atlas Device Sync reached end-of-life September 30, 2025.

MongoDB Realm and Atlas Device Sync (EOL)

> CRITICAL: Atlas Device Sync reached end-of-life September 30, 2025. [source]
> All Device Sync and Device SDK features were shut down on that date. [source]
> This skill provides historical context for customers still migrating away. [source]

What Was Realm / Atlas Device Sync

Realm was a mobile-first database SDK with: [source]
Realm Database (local): Embedded object database for iOS/Android (still available as standalone open-source) [source]
Atlas Device Sync: Cloud sync between Realm local database and MongoDB Atlas (EOL Sep 30 2025) [source]
Device SDKs: Swift, Kotlin, Java, Flutter, React Native, .NET, JavaScript (web) [source]

What Was Flexible Sync (Last Supported Mode)

Flexible Sync replaced Partition-Based Sync as the final architecture: [source]
Subscriptions defined per-client based on query (e.g., realm.query<Task>().where("userId == $0", userId)) [source]
Server-side rules enforced permissions on which documents each client could sync [source]
Offline-first: writes to local Realm database, synced when online [source]

Realm Database (Local — Still Available)

The local Realm Database (without sync) remains available as open-source: [source]
realm-swift - iOS/macOS Swift/Objective-C [source]
realm-kotlin - Android/Kotlin Multiplatform [source]
realm-js - Node.js, React Native [source]
realm-dotnet - .NET/Xamarin [source]
Use Realm local database for: fast local embedded storage without cloud sync requirements. [source]

Migrating Change Listeners to MongoDB Change Streams

What was a Realm change listener: [source]
Replace with a MongoDB change stream consumer in your backend: [source]

Migrating Atlas App Services Authentication

Atlas App Services Authentication providers were also EOL'd September 30, 2025. Migrate to: [source]
Auth0 - drop-in OIDC replacement with mobile SDKs [source]
Firebase Auth - Google's mobile auth platform [source]
AWS Cognito - AWS-native mobile auth [source]
Clerk - Modern developer auth platform [source]

Deprecation References

Atlas Device Sync EOL Forum Post [source]
Realm SDK Migration Guide [source]
Realm Database GitHub (standalone) [source]

Children

Atlas Device Sync Overview (frontier)
Realm SDK Languages and Platforms (frontier)
Flexible Sync (frontier)
Partition-Based Sync (Legacy) (frontier)
Conflict Resolution (frontier)
Realm Object Model (frontier)
Sync Configuration (frontier)
Permissions Model (frontier)
Offline-First Patterns (frontier)
App Services Context (frontier)
Common Pitfalls (frontier)

Frontier under this node: App Services Context, Atlas Device Sync Overview, Common Pitfalls, Conflict Resolution, Flexible Sync, Offline-First Patterns, Partition-Based Sync (Legacy), Permissions Model, Realm SDK Languages and Platforms, Sync Configuration

← the whole tree · 3D view· how to read this page