Index: src/MTXClient.m
==================================================================
--- src/MTXClient.m
+++ src/MTXClient.m
@@ -216,10 +216,24 @@
 			    exceptionWithStatusCode: statusCode
 					   response: response
 					     client: self]);
 			return;
 		}
+
+		OFString *nextBatch = response[@"next_batch"];
+		if (![nextBatch isKindOfClass: OFString.class]) {
+			block([OFInvalidServerReplyException exception]);
+			return;
+		}
+
+		@try {
+			[_storage setNextBatch: nextBatch
+				   forDeviceID: _deviceID];
+		} @catch (id e) {
+			block(e);
+			return;
+		}
 
 		block(nil);
 	}];
 
 	objc_autoreleasePoolPop(pool);

Index: src/MTXSQLite3Storage.m
==================================================================
--- src/MTXSQLite3Storage.m
+++ src/MTXSQLite3Storage.m
@@ -25,10 +25,11 @@
 #import "MTXSQLite3Storage.h"
 
 @implementation MTXSQLite3Storage
 {
 	SL3Connection *_conn;
+	SL3PreparedStatement *_nextBatchSetStatement, *_nextBatchGetStatement;
 }
 
 + (instancetype)storageWithPath: (OFString *)path
 {
 	return [[[self alloc] initWithPath: path] autorelease];
@@ -37,11 +38,27 @@
 - (instancetype)initWithPath: (OFString *)path
 {
 	self = [super init];
 
 	@try {
+		void *pool = objc_autoreleasePoolPush();
+
 		_conn = [[SL3Connection alloc] initWithPath: path];
+
+		[self createTables];
+
+		_nextBatchSetStatement = [[_conn prepareStatement:
+		    @"INSERT OR REPLACE INTO next_batch (\n"
+		    @"    device_id, next_batch\n"
+		    @") VALUES (\n"
+		    @"    $device_id, $next_batch\n"
+		    @")"] retain];
+		_nextBatchGetStatement = [[_conn prepareStatement:
+		    @"SELECT next_batch FROM next_batch\n"
+		    @"WHERE device_id=$device_id"] retain];
+
+		objc_autoreleasePoolPop(pool);
 	} @catch (id e) {
 		[self release];
 		@throw e;
 	}
 
@@ -48,10 +65,55 @@
 	return self;
 }
 
 - (void)dealloc
 {
+	[_nextBatchSetStatement release];
+	[_nextBatchGetStatement release];
 	[_conn release];
 
 	[super dealloc];
 }
+
+- (void)createTables
+{
+	[_conn executeStatement: @"CREATE TABLE IF NOT EXISTS next_batch (\n"
+				 @"    device_id TEXT PRIMARY KEY,\n"
+				 @"    next_batch TEXT\n"
+				 @")"];
+}
+
+- (void)setNextBatch: (OFString *)nextBatch
+	 forDeviceID: (OFString *)deviceID
+{
+	void *pool = objc_autoreleasePoolPush();
+
+	[_nextBatchSetStatement reset];
+	[_nextBatchSetStatement bindWithDictionary: @{
+		@"$device_id": deviceID,
+		@"$next_batch": nextBatch
+	}];
+	[_nextBatchSetStatement step];
+
+	objc_autoreleasePoolPop(pool);
+}
+
+- (OFString *)nextBatchForDeviceID: (OFString *)deviceID
+{
+	void *pool = objc_autoreleasePoolPush();
+
+	[_nextBatchGetStatement reset];
+	[_nextBatchGetStatement bindWithDictionary: @{
+		@"$device_id": deviceID
+	}];
+
+	if (![_nextBatchGetStatement step])
+		return nil;
+
+	OFString *nextBatch =
+	    [[_nextBatchGetStatement rowDictionary][@"next_batch"] retain];
+
+	objc_autoreleasePoolPop(pool);
+
+	return [nextBatch autorelease];
+}
 @end

Index: src/MTXStorage.h
==================================================================
--- src/MTXStorage.h
+++ src/MTXStorage.h
@@ -26,8 +26,25 @@
 
 /**
  * @brief A protocol for a storage to be used by @ref MTXClient.
  */
 @protocol MTXStorage <OFObject>
+/**
+ * @brief Stores the next batch for the specified device.
+ *
+ * @param nextBatch The next batch for the device
+ * @param deviceID The device for which to store the next batch
+ */
+- (void)setNextBatch: (OFString *)nextBatch
+	 forDeviceID: (OFString *)deviceID;
+
+/**
+ * @brief Returns the next batch for the specified device.
+ *
+ * @param deviceID The device ID for which to return the next batch
+ * @return The next batch for the specified device, or `nil` if none is
+ *	   available.
+ */
+- (nullable OFString *)nextBatchForDeviceID: (OFString *)deviceID;
 @end
 
 OF_ASSUME_NONNULL_END