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Realm Cocoa V10.0.0 Released

Learn more about the Realm SDKs 10.0 Release on our Developer Hub HERE

This release is functionally identical to v10.0.0-rc.2.

NOTE: This version upgrades the Realm file format version to add support for new data types. Realm files opened will be automatically upgraded and cannot be read by versions older than v10.0.0.

Breaking Changes

  • Rename Realm.Publishers to RealmPublishers to avoid confusion with Combine.Publishers.
  • Remove [RLMSyncManager shared] . This is now instatiated as a property on App/RLMApp.
  • RLMSyncManager.pinnedCertificatePaths has been removed.
  • Classes RLMUserAccountInfo & RLMUserInfo (swift: UserInfo , UserAccountInfo ) have been removed.
  • RLMSyncUser / SyncUser has been renamed to RLMUser / User .
  • We no longer support Realm Cloud (legacy), but instead the new “MongoDB Realm” Cloud. MongoDB Realm is a serverless platform that enables developers to quickly build applications without having to set up server infrastructure. MongoDB Realm is built on top of MongoDB Atlas, automatically integrating the connection to your database.
  • Remove support for Query-based sync, including the configuration parameters and the RLMSyncSubscription and SyncSubscription types (#6437).
  • Remove everything related to sync permissions, including both the path-based permission system and the object-level privileges for query-based sync. Permissions are now configured via MongoDB Atlas. (#6445)
  • Remove support for Realm Object Server.
  • Non-embedded objects in synchronized Realms must always have a primary key named “_id”.
  • All Swift callbacks for asynchronous operations which can fail are now passed a Result<Value, Error> parameter instead of two separate Value? and Error? parameters.


  • Add support for next generation sync. Support for syncing to MongoDB instead of Realm Object Server. Applications must be created at

  • The memory mapping scheme for Realm files has changed to better support opening very large files.

  • Add support for the ObjectId data type. This is an automatically-generated unique identifier similar to a GUID or a UUID. (PR #6450).

  • Add support for the Decimal128 data type. This is a 128-bit IEEE 754 decimal floating point number similar to NSDecimalNumber. (PR #6450).

  • Add support for embedded objects. Embedded objects are objects which are owned by a single parent object, and are deleted when that parent object is deleted. They are defined by subclassing EmbeddedObject / RLMEmbeddedObject rather than Object / RLMObject .

  • Add [RLMUser customData]

  • / User.customData . Custom data is configured in your MongoDB Realm App.

  • Add [RLMUser callFunctionNamed:arguments:completion:]

  • / User.functions . This is the entry point for calling Remote MongoDB Realm functions. Functions allow you to define and execute server-side logic for your application. Functions are written in modern JavaScript (ES6+) and execute in a serverless manner. When you call a function, you can dynamically access components of the current application as well as information about the request to execute the function and the logged in user that sent the request.

  • Add [RLMUser mongoClientWithServiceName:] / User.mongoClient . This is the entry point for calling your Remote MongoDB Service. The read operations are [RLMMongoCollection findWhere:completion:] , [RLMMongoCollection countWhere:completion:] and [RLMMongoCollection aggregateWithPipeline:completion:] . The write operations are [RLMMongoCollection insertOneDocument:completion:] , [RLMMongoCollection insertManyDocuments:completion:] , [RLMMongoCollection updateOneDocument:completion:] , [RLMMongoCollection updateManyDocuments:completion:] , [RLMMongoCollection deleteOneDocument:completion:] , and [RLMMongoCollection deleteManyDocuments:completion:] . If you are already familiar with MongoDB drivers, it is important to understand that the remote MongoCollection only provides access to the operations available in MongoDB Realm.

  • Obtaining a Realm configuration from a user is now done with [RLMUser configurationWithPartitionValue:] / User.configuration(partitionValue:) . Partition values can currently be of types String , Int , or ObjectId , and fill a similar role to Realm URLs did with Realm Cloud. The main difference is that partitions are meant to be more closely associated with your data. For example, if you are running a Dog kennel, and have a field breed that acts as your partition key, you could open up realms based on the breed of the dogs.

  • Add ability to stream change events on a remote MongoDB collection with [RLMMongoCollection watch:delegate:delegateQueue:] , . When calling watch(delegate:) you will be given a RLMChangeStream ( ChangeStream ) which can be used to end watching by calling close() . Change events can also be streamed using the Combine publisher that will stream change events each time the remote MongoDB collection is updated.

  • Add the ability to listen for when a Watch Change Stream is opened when using Combine. Use onOpen(event:) directly after opening a WatchPublisher to register a callback to be invoked once the change stream is opened.

  • Objects with integer primary keys no longer require a separate index for the primary key column, improving insert performance and slightly reducing file size.

  • Realm Studio: 10.0.0 or later.

  • Carthage release for Swift is built with Xcode 12

  • Upgraded realm-core from v6.1.4 to v10.0.0

  • Upgraded realm-sync from v5.0.29 to v10.0.0

Any concept code on how to setup and use the mongoClientWithServiceName?

This seems like a good choice to authenticate with? The only reference I can find is in the release note but nothing more.

Thanks Barry - we’re currently in the process of creating new, and updating older, sample apps and code and so we’ll certainly look to include examples on how to setup and use the mongoClientWithServiceName

Keep an eye on the Forums, and also the Developer Hub too