--- /dev/null
+////////////////////////////////////////////////////////////////////////////
+//
+// Copyright 2016 Realm Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+////////////////////////////////////////////////////////////////////////////
+
+#import "RLMSyncUser.h"
+
+#import "RLMSyncConfiguration.h"
+#import "RLMSyncUtil_Private.h"
+
+#import "sync/sync_config.hpp"
+#import "sync/sync_user.hpp"
+#import "sync/impl/sync_metadata.hpp"
+
+@class RLMSyncConfiguration, RLMSyncSessionRefreshHandle;
+
+using namespace realm;
+
+typedef void(^RLMFetchedRealmCompletionBlock)(NSError * _Nullable, RLMRealm * _Nullable, BOOL * _Nonnull);
+
+NS_ASSUME_NONNULL_BEGIN
+
+class CocoaSyncUserContext : public SyncUserContext {
+public:
+ void register_refresh_handle(const std::string& path, RLMSyncSessionRefreshHandle *handle);
+ void unregister_refresh_handle(const std::string& path);
+ void invalidate_all_handles();
+
+ RLMUserErrorReportingBlock error_handler() const;
+ void set_error_handler(RLMUserErrorReportingBlock);
+
+private:
+ /**
+ A map of paths to 'refresh handles'.
+
+ A refresh handle is an object that encapsulates the concept of periodically
+ refreshing the Realm's access token before it expires. Tokens are indexed by their
+ paths (e.g. `/~/path/to/realm`).
+ */
+ std::unordered_map<std::string, RLMSyncSessionRefreshHandle *> m_refresh_handles;
+ std::mutex m_mutex;
+
+ /**
+ An optional callback invoked when the authentication server reports the user as
+ being in an expired state.
+ */
+ RLMUserErrorReportingBlock m_error_handler;
+ mutable std::mutex m_error_handler_mutex;
+};
+
+@interface RLMSyncUser ()
+
+- (instancetype)initWithSyncUser:(std::shared_ptr<SyncUser>)user;
+- (std::shared_ptr<SyncUser>)_syncUser;
+- (nullable NSString *)_refreshToken;
++ (void)_setUpBindingContextFactory;
+@end
+
+using PermissionChangeCallback = std::function<void(std::exception_ptr)>;
+
+PermissionChangeCallback RLMWrapPermissionStatusCallback(RLMPermissionStatusBlock callback);
+
+NS_ASSUME_NONNULL_END