diff --git a/packages/cloud_firestore/cloud_firestore/lib/cloud_firestore.dart b/packages/cloud_firestore/cloud_firestore/lib/cloud_firestore.dart
index aef386e77d26..ac1e82df64b4 100755
--- a/packages/cloud_firestore/cloud_firestore/lib/cloud_firestore.dart
+++ b/packages/cloud_firestore/cloud_firestore/lib/cloud_firestore.dart
@@ -9,6 +9,7 @@ import 'dart:convert';
 import 'dart:typed_data';
 import 'dart:ui' show hashValues, hashList;
 
+import 'package:cloud_firestore_platform_interface/cloud_firestore_platform_interface.dart';
 import 'package:collection/collection.dart';
 import 'package:firebase_core/firebase_core.dart';
 import 'package:flutter/foundation.dart' show ReadBuffer, WriteBuffer;
@@ -17,6 +18,9 @@ import 'package:meta/meta.dart';
 
 import 'src/utils/auto_id_generator.dart';
 
+import 'package:cloud_firestore_platform_interface/cloud_firestore_platform_interface.dart'
+  show Source;
+
 part 'src/blob.dart';
 part 'src/collection_reference.dart';
 part 'src/document_change.dart';
@@ -33,4 +37,3 @@ part 'src/snapshot_metadata.dart';
 part 'src/timestamp.dart';
 part 'src/transaction.dart';
 part 'src/write_batch.dart';
-part 'src/source.dart';
diff --git a/packages/cloud_firestore/cloud_firestore/lib/src/document_reference.dart b/packages/cloud_firestore/cloud_firestore/lib/src/document_reference.dart
index 413cf41be0be..ec2ee9d467fa 100644
--- a/packages/cloud_firestore/cloud_firestore/lib/src/document_reference.dart
+++ b/packages/cloud_firestore/cloud_firestore/lib/src/document_reference.dart
@@ -48,15 +48,12 @@ class DocumentReference {
   /// If [merge] is true, the provided data will be merged into an
   /// existing document instead of overwriting.
   Future<void> setData(Map<String, dynamic> data, {bool merge = false}) {
-    return Firestore.channel.invokeMethod<void>(
-      'DocumentReference#setData',
-      <String, dynamic>{
-        'app': firestore.app.name,
-        'path': path,
-        'data': data,
-        'options': <String, bool>{'merge': merge},
-      },
-    );
+    return Firestore.platform.documentReference.set(
+        firestore.app.name,
+        path: path,
+        data: data,
+        options: PlatformSetOptions(merge: merge),
+      );
   }
 
   /// Updates fields in the document referred to by this [DocumentReference].
@@ -66,44 +63,38 @@ class DocumentReference {
   ///
   /// If no document exists yet, the update will fail.
   Future<void> updateData(Map<String, dynamic> data) {
-    return Firestore.channel.invokeMethod<void>(
-      'DocumentReference#updateData',
-      <String, dynamic>{
-        'app': firestore.app.name,
-        'path': path,
-        'data': data,
-      },
-    );
+    return Firestore.platform.documentReference.update(
+        firestore.app.name,
+        path: path,
+        data: data,
+      );
   }
 
   /// Reads the document referenced by this [DocumentReference].
   ///
   /// If no document exists, the read will return null.
   Future<DocumentSnapshot> get({Source source = Source.serverAndCache}) async {
-    final Map<String, dynamic> data =
-        await Firestore.channel.invokeMapMethod<String, dynamic>(
-      'DocumentReference#get',
-      <String, dynamic>{
-        'app': firestore.app.name,
-        'path': path,
-        'source': _getSourceString(source),
-      },
-    );
+    final PlatformDocumentSnapshot snapshot = await Firestore.platform.documentReference.get(
+        firestore.app.name,
+        path: path,
+        source: source,
+      );
+
     return DocumentSnapshot._(
-      data['path'],
-      _asStringKeyedMap(data['data']),
-      SnapshotMetadata._(data['metadata']['hasPendingWrites'],
-          data['metadata']['isFromCache']),
+      snapshot.path,
+      _asStringKeyedMap(snapshot.data),
+      SnapshotMetadata._(snapshot.metadata.hasPendingWrites,
+          snapshot.metadata.isFromCache),
       firestore,
     );
   }
 
   /// Deletes the document referred to by this [DocumentReference].
   Future<void> delete() {
-    return Firestore.channel.invokeMethod<void>(
-      'DocumentReference#delete',
-      <String, dynamic>{'app': firestore.app.name, 'path': path},
-    );
+    return Firestore.platform.documentReference.delete(
+        firestore.app.name,
+        path: path,
+      );
   }
 
   /// Returns the reference of a collection contained inside of this
@@ -118,34 +109,19 @@ class DocumentReference {
   // TODO(jackson): Reduce code duplication with [Query]
   Stream<DocumentSnapshot> snapshots({bool includeMetadataChanges = false}) {
     assert(includeMetadataChanges != null);
-    Future<int> _handle;
-    // It's fine to let the StreamController be garbage collected once all the
-    // subscribers have cancelled; this analyzer warning is safe to ignore.
-    StreamController<DocumentSnapshot> controller; // ignore: close_sinks
-    controller = StreamController<DocumentSnapshot>.broadcast(
-      onListen: () {
-        _handle = Firestore.channel.invokeMethod<int>(
-          'DocumentReference#addSnapshotListener',
-          <String, dynamic>{
-            'app': firestore.app.name,
-            'path': path,
-            'includeMetadataChanges': includeMetadataChanges,
-          },
-        ).then<int>((dynamic result) => result);
-        _handle.then((int handle) {
-          Firestore._documentObservers[handle] = controller;
-        });
-      },
-      onCancel: () {
-        _handle.then((int handle) async {
-          await Firestore.channel.invokeMethod<void>(
-            'removeListener',
-            <String, dynamic>{'handle': handle},
-          );
-          Firestore._documentObservers.remove(handle);
-        });
-      },
-    );
-    return controller.stream;
+
+    return Firestore.platform.documentReference.snapshots(
+        firestore.app.name,
+        path: path,
+        includeMetadataChanges: includeMetadataChanges,
+      ).map((PlatformDocumentSnapshot snapshot) {
+        return DocumentSnapshot._(
+          snapshot.path,
+          _asStringKeyedMap(snapshot.data),
+          SnapshotMetadata._(snapshot.metadata.hasPendingWrites,
+              snapshot.metadata.isFromCache),
+          firestore,
+        );
+      });
   }
 }
diff --git a/packages/cloud_firestore/cloud_firestore/lib/src/firestore.dart b/packages/cloud_firestore/cloud_firestore/lib/src/firestore.dart
index 5c164ed1e122..7f43ce6a806c 100644
--- a/packages/cloud_firestore/cloud_firestore/lib/src/firestore.dart
+++ b/packages/cloud_firestore/cloud_firestore/lib/src/firestore.dart
@@ -8,32 +8,11 @@ part of cloud_firestore;
 ///
 /// You can get an instance by calling [Firestore.instance].
 class Firestore {
-  Firestore({FirebaseApp app}) : app = app ?? FirebaseApp.instance {
-    if (_initialized) return;
-    channel.setMethodCallHandler((MethodCall call) async {
-      if (call.method == 'QuerySnapshot') {
-        final QuerySnapshot snapshot = QuerySnapshot._(call.arguments, this);
-        _queryObservers[call.arguments['handle']].add(snapshot);
-      } else if (call.method == 'DocumentSnapshot') {
-        final DocumentSnapshot snapshot = DocumentSnapshot._(
-          call.arguments['path'],
-          _asStringKeyedMap(call.arguments['data']),
-          SnapshotMetadata._(call.arguments['metadata']['hasPendingWrites'],
-              call.arguments['metadata']['isFromCache']),
-          this,
-        );
-        _documentObservers[call.arguments['handle']].add(snapshot);
-      } else if (call.method == 'DoTransaction') {
-        final int transactionId = call.arguments['transactionId'];
-        final Transaction transaction = Transaction(transactionId, this);
-        final dynamic result =
-            await _transactionHandlers[transactionId](transaction);
-        await transaction._finish();
-        return result;
-      }
-    });
-    _initialized = true;
-  }
+  Firestore({FirebaseApp app}) : app = app ?? FirebaseApp.instance;
+
+  /// The platform instance that talks to the native side of the plugin.
+  @visibleForTesting
+  static final FirestorePlatform platform = FirestorePlatform.instance ?? (FirestorePlatform.instance = MethodChannelFirestore(FirestoreMessageCodec()));
 
   /// Gets the instance of Firestore for the default Firebase app.
   static final Firestore instance = Firestore();
@@ -43,24 +22,6 @@ class Firestore {
   /// If null, the default [FirebaseApp] is used.
   final FirebaseApp app;
 
-  static bool _initialized = false;
-
-  @visibleForTesting
-  static const MethodChannel channel = MethodChannel(
-    'plugins.flutter.io/cloud_firestore',
-    StandardMethodCodec(FirestoreMessageCodec()),
-  );
-
-  static final Map<int, StreamController<QuerySnapshot>> _queryObservers =
-      <int, StreamController<QuerySnapshot>>{};
-
-  static final Map<int, StreamController<DocumentSnapshot>> _documentObservers =
-      <int, StreamController<DocumentSnapshot>>{};
-
-  static final Map<int, TransactionHandler> _transactionHandlers =
-      <int, TransactionHandler>{};
-  static int _transactionHandlerId = 0;
-
   @override
   bool operator ==(dynamic o) => o is Firestore && o.app == app;
 
@@ -123,39 +84,41 @@ class Firestore {
       {Duration timeout = const Duration(seconds: 5)}) async {
     assert(timeout.inMilliseconds > 0,
         'Transaction timeout must be more than 0 milliseconds');
-    final int transactionId = _transactionHandlerId++;
-    _transactionHandlers[transactionId] = transactionHandler;
-    final Map<String, dynamic> result = await channel
-        .invokeMapMethod<String, dynamic>(
-            'Firestore#runTransaction', <String, dynamic>{
-      'app': app.name,
-      'transactionId': transactionId,
-      'transactionTimeout': timeout.inMilliseconds
-    });
+
+    // Wrap the user-supplied [TransactionHandler] into something that can be passed to the Platform implementation.
+    final PlatformTransactionHandler handler = (PlatformTransaction platformTransaction) async {
+      Transaction transaction = Transaction(platformTransaction.transactionId, this);
+      final dynamic result = await transactionHandler(transaction);
+      await transaction._finish();
+      return result;
+    };
+
+    final Map<String, dynamic> result = await Firestore.platform.transaction.run(
+      app.name,
+      updateFunction: handler,
+      transactionTimeout: timeout.inMilliseconds,
+    );
+
     return result ?? <String, dynamic>{};
   }
 
   @deprecated
-  Future<void> enablePersistence(bool enable) async {
+  Future<void> enablePersistence(bool enable) {
     assert(enable != null);
-    await channel
-        .invokeMethod<void>('Firestore#enablePersistence', <String, dynamic>{
-      'app': app.name,
-      'enable': enable,
-    });
+    return Firestore.platform.enablePersistence(app.name, enable: enable);
   }
 
   Future<void> settings(
       {bool persistenceEnabled,
       String host,
       bool sslEnabled,
-      int cacheSizeBytes}) async {
-    await channel.invokeMethod<void>('Firestore#settings', <String, dynamic>{
-      'app': app.name,
-      'persistenceEnabled': persistenceEnabled,
-      'host': host,
-      'sslEnabled': sslEnabled,
-      'cacheSizeBytes': cacheSizeBytes,
-    });
+      int cacheSizeBytes}) {
+
+    return Firestore.platform.settings(app.name, 
+        persistenceEnabled: persistenceEnabled,
+        host: host,
+        sslEnabled: sslEnabled,
+        cacheSizeBytes: cacheSizeBytes,
+      );
   }
 }
diff --git a/packages/cloud_firestore/cloud_firestore/lib/src/query.dart b/packages/cloud_firestore/cloud_firestore/lib/src/query.dart
index 2da85859ee5a..2fb33b7575f5 100644
--- a/packages/cloud_firestore/cloud_firestore/lib/src/query.dart
+++ b/packages/cloud_firestore/cloud_firestore/lib/src/query.dart
@@ -52,55 +52,30 @@ class Query {
   // TODO(jackson): Reduce code duplication with [DocumentReference]
   Stream<QuerySnapshot> snapshots({bool includeMetadataChanges = false}) {
     assert(includeMetadataChanges != null);
-    Future<int> _handle;
-    // It's fine to let the StreamController be garbage collected once all the
-    // subscribers have cancelled; this analyzer warning is safe to ignore.
-    StreamController<QuerySnapshot> controller; // ignore: close_sinks
-    controller = StreamController<QuerySnapshot>.broadcast(
-      onListen: () {
-        _handle = Firestore.channel.invokeMethod<int>(
-          'Query#addSnapshotListener',
-          <String, dynamic>{
-            'app': firestore.app.name,
-            'path': _path,
-            'isCollectionGroup': _isCollectionGroup,
-            'parameters': _parameters,
-            'includeMetadataChanges': includeMetadataChanges,
-          },
-        ).then<int>((dynamic result) => result);
-        _handle.then((int handle) {
-          Firestore._queryObservers[handle] = controller;
-        });
-      },
-      onCancel: () {
-        _handle.then((int handle) async {
-          await Firestore.channel.invokeMethod<void>(
-            'removeListener',
-            <String, dynamic>{'handle': handle},
-          );
-          Firestore._queryObservers.remove(handle);
-        });
-      },
-    );
-    return controller.stream;
+
+    return Firestore.platform.query.snapshots(
+        firestore.app.name,
+        path: _path,
+        isCollectionGroup: _isCollectionGroup,
+        parameters: _parameters,
+        includeMetadataChanges: includeMetadataChanges,
+      ).map((PlatformQuerySnapshot snapshot) => QuerySnapshot._(snapshot.asMap(), firestore));
   }
 
   /// Fetch the documents for this query
   Future<QuerySnapshot> getDocuments(
       {Source source = Source.serverAndCache}) async {
     assert(source != null);
-    final Map<dynamic, dynamic> data =
-        await Firestore.channel.invokeMapMethod<String, dynamic>(
-      'Query#getDocuments',
-      <String, dynamic>{
-        'app': firestore.app.name,
-        'path': _path,
-        'isCollectionGroup': _isCollectionGroup,
-        'parameters': _parameters,
-        'source': _getSourceString(source),
-      },
-    );
-    return QuerySnapshot._(data, firestore);
+
+    final PlatformQuerySnapshot snapshot = await Firestore.platform.query.getDocuments(
+        firestore.app.name,
+        path: _path,
+        isCollectionGroup: _isCollectionGroup,
+        parameters: _parameters,
+        source: source,
+      );
+        
+    return QuerySnapshot._(snapshot.asMap(), firestore);
   }
 
   /// Obtains a CollectionReference corresponding to this query's location.
diff --git a/packages/cloud_firestore/cloud_firestore/lib/src/transaction.dart b/packages/cloud_firestore/cloud_firestore/lib/src/transaction.dart
index d13e3f19f9b2..757523f5af46 100644
--- a/packages/cloud_firestore/cloud_firestore/lib/src/transaction.dart
+++ b/packages/cloud_firestore/cloud_firestore/lib/src/transaction.dart
@@ -23,18 +23,18 @@ class Transaction {
   }
 
   Future<DocumentSnapshot> _get(DocumentReference documentReference) async {
-    final Map<String, dynamic> result = await Firestore.channel
-        .invokeMapMethod<String, dynamic>('Transaction#get', <String, dynamic>{
-      'app': _firestore.app.name,
-      'transactionId': _transactionId,
-      'path': documentReference.path,
-    });
+    final PlatformDocumentSnapshot result = await Firestore.platform.transaction.get(
+        _firestore.app.name, 
+        transactionId: _transactionId, 
+        path: documentReference.path,
+      );
+
     if (result != null) {
       return DocumentSnapshot._(
           documentReference.path,
-          result['data']?.cast<String, dynamic>(),
-          SnapshotMetadata._(result['metadata']['hasPendingWrites'],
-              result['metadata']['isFromCache']),
+          result.data,
+          SnapshotMetadata._(result.metadata.hasPendingWrites,
+              result.metadata.isFromCache),
           _firestore);
     } else {
       return null;
@@ -51,13 +51,12 @@ class Transaction {
     return result;
   }
 
-  Future<void> _delete(DocumentReference documentReference) async {
-    return Firestore.channel
-        .invokeMethod<void>('Transaction#delete', <String, dynamic>{
-      'app': _firestore.app.name,
-      'transactionId': _transactionId,
-      'path': documentReference.path,
-    });
+  Future<void> _delete(DocumentReference documentReference) {
+    return Firestore.platform.transaction.delete(
+        _firestore.app.name, 
+        transactionId: _transactionId, 
+        path: documentReference.path,
+      );
   }
 
   /// Updates fields in the document referred to by [documentReference].
@@ -73,14 +72,13 @@ class Transaction {
   }
 
   Future<void> _update(
-      DocumentReference documentReference, Map<String, dynamic> data) async {
-    return Firestore.channel
-        .invokeMethod<void>('Transaction#update', <String, dynamic>{
-      'app': _firestore.app.name,
-      'transactionId': _transactionId,
-      'path': documentReference.path,
-      'data': data,
-    });
+      DocumentReference documentReference, Map<String, dynamic> data) {
+    return Firestore.platform.transaction.update(
+        _firestore.app.name,
+        transactionId: _transactionId,
+        path: documentReference.path,
+        data: data,
+      );
   }
 
   /// Writes to the document referred to by the provided [DocumentReference].
@@ -97,13 +95,12 @@ class Transaction {
   }
 
   Future<void> _set(
-      DocumentReference documentReference, Map<String, dynamic> data) async {
-    return Firestore.channel
-        .invokeMethod<void>('Transaction#set', <String, dynamic>{
-      'app': _firestore.app.name,
-      'transactionId': _transactionId,
-      'path': documentReference.path,
-      'data': data,
-    });
+      DocumentReference documentReference, Map<String, dynamic> data) {
+    return Firestore.platform.transaction.set(
+        _firestore.app.name,
+        transactionId: _transactionId,
+        path: documentReference.path,
+        data: data
+      );
   }
 }
diff --git a/packages/cloud_firestore/cloud_firestore/lib/src/write_batch.dart b/packages/cloud_firestore/cloud_firestore/lib/src/write_batch.dart
index 6a41ee7bfec3..212a72dc32f5 100644
--- a/packages/cloud_firestore/cloud_firestore/lib/src/write_batch.dart
+++ b/packages/cloud_firestore/cloud_firestore/lib/src/write_batch.dart
@@ -12,49 +12,47 @@ part of cloud_firestore;
 /// nor can it be committed again.
 class WriteBatch {
   WriteBatch._(this._firestore)
-      : _handle = Firestore.channel.invokeMethod<dynamic>(
-            'WriteBatch#create', <String, dynamic>{'app': _firestore.app.name});
+      : _handle = Firestore.platform.writeBatch.create(_firestore.app.name);
 
   final Firestore _firestore;
-  Future<dynamic> _handle;
+  Future<PlatformWriteBatchHandle> _handle;
   final List<Future<dynamic>> _actions = <Future<dynamic>>[];
 
   /// Indicator to whether or not this [WriteBatch] has been committed.
   bool _committed = false;
 
+  // This method throws a [StateError] if this [WriteBatch] has already been committed.
+  void _ensureNotCommitted() {
+    if (_committed) {
+      throw StateError(
+        "This batch has been committed and can no longer be changed.");
+    }
+  }
+
   /// Commits all of the writes in this write batch as a single atomic unit.
   ///
   /// Calling this method prevents any future operations from being added.
   Future<void> commit() async {
-    if (!_committed) {
-      _committed = true;
-      await Future.wait<dynamic>(_actions);
-      await Firestore.channel.invokeMethod<void>(
-          'WriteBatch#commit', <String, dynamic>{'handle': await _handle});
-    } else {
-      throw StateError("This batch has already been committed.");
-    }
+    _ensureNotCommitted();
+
+    _committed = true;
+    await Future.wait<dynamic>(_actions);
+    await Firestore.platform.writeBatch.commit(handle: await _handle);
   }
 
   /// Deletes the document referred to by [document].
   void delete(DocumentReference document) {
-    if (!_committed) {
-      _handle.then((dynamic handle) {
-        _actions.add(
-          Firestore.channel.invokeMethod<void>(
-            'WriteBatch#delete',
-            <String, dynamic>{
-              'app': _firestore.app.name,
-              'handle': handle,
-              'path': document.path,
-            },
-          ),
-        );
-      });
-    } else {
-      throw StateError(
-          "This batch has been committed and can no longer be changed.");
-    }
+    _ensureNotCommitted();
+
+    _handle.then((PlatformWriteBatchHandle handle) {
+      _actions.add(
+        Firestore.platform.writeBatch.delete(
+            _firestore.app.name,
+            handle: handle,
+            path: document.path,
+          )
+      );
+    });
   }
 
   /// Writes to the document referred to by [document].
@@ -65,48 +63,36 @@ class WriteBatch {
   /// existing document instead of overwriting.
   void setData(DocumentReference document, Map<String, dynamic> data,
       {bool merge = false}) {
-    if (!_committed) {
-      _handle.then((dynamic handle) {
-        _actions.add(
-          Firestore.channel.invokeMethod<void>(
-            'WriteBatch#setData',
-            <String, dynamic>{
-              'app': _firestore.app.name,
-              'handle': handle,
-              'path': document.path,
-              'data': data,
-              'options': <String, bool>{'merge': merge},
-            },
-          ),
-        );
-      });
-    } else {
-      throw StateError(
-          "This batch has been committed and can no longer be changed.");
-    }
+    _ensureNotCommitted();
+
+    _handle.then((PlatformWriteBatchHandle handle) {
+      _actions.add(
+        Firestore.platform.writeBatch.set(
+            _firestore.app.name,
+            handle: handle,
+            path: document.path,
+            data: data,
+            options: PlatformSetOptions(merge: merge),
+          )
+      );
+    });
   }
 
   /// Updates fields in the document referred to by [document].
   ///
   /// If the document does not exist, the operation will fail.
   void updateData(DocumentReference document, Map<String, dynamic> data) {
-    if (!_committed) {
-      _handle.then((dynamic handle) {
-        _actions.add(
-          Firestore.channel.invokeMethod<void>(
-            'WriteBatch#updateData',
-            <String, dynamic>{
-              'app': _firestore.app.name,
-              'handle': handle,
-              'path': document.path,
-              'data': data,
-            },
-          ),
-        );
-      });
-    } else {
-      throw StateError(
-          "This batch has been committed and can no longer be changed.");
-    }
+    _ensureNotCommitted();
+
+    _handle.then((PlatformWriteBatchHandle handle) {
+      _actions.add(
+        Firestore.platform.writeBatch.update(
+            _firestore.app.name,
+            handle: handle,
+            path: document.path,
+            data: data,
+          )
+      );
+    });
   }
 }
diff --git a/packages/cloud_firestore/cloud_firestore/pubspec.yaml b/packages/cloud_firestore/cloud_firestore/pubspec.yaml
index 1bef85841f13..b044f357ed6e 100755
--- a/packages/cloud_firestore/cloud_firestore/pubspec.yaml
+++ b/packages/cloud_firestore/cloud_firestore/pubspec.yaml
@@ -15,6 +15,8 @@ flutter:
         pluginClass: FLTCloudFirestorePlugin
 
 dependencies:
+  cloud_firestore_platform_interface:
+    path: ../cloud_firestore_platform_interface
   flutter:
     sdk: flutter
   meta: "^1.0.5"
diff --git a/packages/cloud_firestore/cloud_firestore/test/cloud_firestore_test.dart b/packages/cloud_firestore/cloud_firestore/test/cloud_firestore_test.dart
index 328427f46e04..92b807b30fc9 100755
--- a/packages/cloud_firestore/cloud_firestore/test/cloud_firestore_test.dart
+++ b/packages/cloud_firestore/cloud_firestore/test/cloud_firestore_test.dart
@@ -6,6 +6,7 @@ import 'dart:async';
 import 'dart:typed_data';
 
 import 'package:cloud_firestore/cloud_firestore.dart';
+import 'package:cloud_firestore_platform_interface/cloud_firestore_platform_interface.dart';
 import 'package:firebase_core/firebase_core.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_test/flutter_test.dart';
@@ -48,7 +49,8 @@ void main() {
       collectionReference = firestore.collection('foo');
       collectionGroupQuery = firestore.collectionGroup('bar');
       transaction = Transaction(0, firestore);
-      Firestore.channel.setMockMethodCallHandler((MethodCall methodCall) async {
+
+      Function methodCallHandler = (MethodCall methodCall) async {
         log.add(methodCall);
         switch (methodCall.method) {
           case 'Query#addSnapshotListener':
@@ -60,8 +62,8 @@ void main() {
               // https://github.com/flutter/flutter/issues/33446
               // ignore: deprecated_member_use
               BinaryMessages.handlePlatformMessage(
-                Firestore.channel.name,
-                Firestore.channel.codec.encodeMethodCall(
+                MethodChannelFirestore.channel.name,
+                MethodChannelFirestore.channel.codec.encodeMethodCall(
                   MethodCall('QuerySnapshot', <String, dynamic>{
                     'app': app.name,
                     'handle': handle,
@@ -93,8 +95,8 @@ void main() {
               // https://github.com/flutter/flutter/issues/33446
               // ignore: deprecated_member_use
               BinaryMessages.handlePlatformMessage(
-                Firestore.channel.name,
-                Firestore.channel.codec.encodeMethodCall(
+                MethodChannelFirestore.channel.name,
+                MethodChannelFirestore.channel.codec.encodeMethodCall(
                   MethodCall('DocumentSnapshot', <String, dynamic>{
                     'handle': handle,
                     'path': methodCall.arguments['path'],
@@ -167,7 +169,14 @@ void main() {
           default:
             return null;
         }
-      });
+      };
+
+      // Ensure the MethodChannel platforms are initialized
+      Firestore.platform;
+
+      // All the MethodChannel implementation share the same channel
+      MethodChannelFirestore.channel.setMockMethodCallHandler(methodCallHandler);
+
       log.clear();
     });
 
diff --git a/packages/cloud_firestore/cloud_firestore_platform_interface/CHANGELOG.md b/packages/cloud_firestore/cloud_firestore_platform_interface/CHANGELOG.md
new file mode 100644
index 000000000000..6fadda91b380
--- /dev/null
+++ b/packages/cloud_firestore/cloud_firestore_platform_interface/CHANGELOG.md
@@ -0,0 +1,3 @@
+## 1.0.0
+
+- Initial open-source release.
diff --git a/packages/cloud_firestore/cloud_firestore_platform_interface/LICENSE b/packages/cloud_firestore/cloud_firestore_platform_interface/LICENSE
new file mode 100644
index 000000000000..000b4618d2bd
--- /dev/null
+++ b/packages/cloud_firestore/cloud_firestore_platform_interface/LICENSE
@@ -0,0 +1,27 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//    * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//    * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//    * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
\ No newline at end of file
diff --git a/packages/cloud_firestore/cloud_firestore_platform_interface/README.md b/packages/cloud_firestore/cloud_firestore_platform_interface/README.md
new file mode 100644
index 000000000000..1af6a2d43467
--- /dev/null
+++ b/packages/cloud_firestore/cloud_firestore_platform_interface/README.md
@@ -0,0 +1,26 @@
+# cloud_firestore_platform_interface
+
+A common platform interface for the [`cloud_firestore`][1] plugin.
+
+This interface allows platform-specific implementations of the `cloud_firestore`
+plugin, as well as the plugin itself, to ensure they are supporting the
+same interface.
+
+# Usage
+
+To implement a new platform-specific implementation of `cloud_firestore`, extend
+[`CloudFirestorePlatform`][2] with an implementation that performs the
+platform-specific behavior, and when you register your plugin, set the default
+`CloudFirestorePlatform` by calling
+`CloudFirestorePlatform.instance = MyCloudFirestore()`.
+
+# Note on breaking changes
+
+Strongly prefer non-breaking changes (such as adding a method to the interface)
+over breaking changes for this package.
+
+See https://flutter.dev/go/platform-interface-breaking-changes for a discussion
+on why a less-clean interface is preferable to a breaking change.
+
+[1]: ../cloud_firestore
+[2]: lib/cloud_firestore_platform_interface.dart
diff --git a/packages/cloud_firestore/cloud_firestore_platform_interface/lib/cloud_firestore_platform_interface.dart b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/cloud_firestore_platform_interface.dart
new file mode 100644
index 000000000000..7fc4e7eabba9
--- /dev/null
+++ b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/cloud_firestore_platform_interface.dart
@@ -0,0 +1,7 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+export 'src/implementations.dart';
+export 'src/interfaces.dart';
+export 'src/types.dart';
diff --git a/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/implementations.dart b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/implementations.dart
new file mode 100644
index 000000000000..bec4a06b131e
--- /dev/null
+++ b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/implementations.dart
@@ -0,0 +1,9 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+export 'implementations/method_channel_document_reference.dart';
+export 'implementations/method_channel_firestore.dart';
+export 'implementations/method_channel_query.dart';
+export 'implementations/method_channel_transaction.dart';
+export 'implementations/method_channel_write_batch.dart';
diff --git a/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/implementations/method_channel_document_reference.dart b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/implementations/method_channel_document_reference.dart
new file mode 100644
index 000000000000..e978275d7447
--- /dev/null
+++ b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/implementations/method_channel_document_reference.dart
@@ -0,0 +1,172 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+import 'dart:async';
+
+import 'package:flutter/services.dart';
+import 'package:meta/meta.dart' show required, visibleForTesting;
+
+import './multi_method_channel.dart';
+import '../interfaces/document_reference_platform.dart';
+import '../types.dart';
+
+class MethodChannelDocumentReference extends DocumentReferencePlatform {
+  MethodChannelDocumentReference(MultiMethodChannel channel) {
+    MethodChannelDocumentReference._channel = channel;
+    MethodChannelDocumentReference._channel.addMethodCallHandler('DocumentSnapshot', this._handleDocumentSnapshot);
+  }
+
+  @visibleForTesting
+  static MultiMethodChannel get channel => MethodChannelDocumentReference._channel;
+  static MultiMethodChannel _channel;
+
+  void _handleDocumentSnapshot(MethodCall call) {
+    final int handle = call.arguments['handle'];
+    _documentSnapshotStreamControllers[handle].add(
+      PlatformDocumentSnapshot(
+          path: call.arguments['path'],
+          data: call.arguments['data']?.cast<String, dynamic>(),
+          metadata: PlatformSnapshotMetadata(
+              hasPendingWrites: call.arguments['metadata']['hasPendingWrites'],
+              isFromCache: call.arguments['metadata']['isFromCache'],
+            ),
+        )
+    );
+  }
+
+  /// Reads the document referred to by this [path].
+  /// By default, get() attempts to provide up-to-date data when possible by waiting for
+  /// data from the server, but it may return cached data or fail if you are offline and
+  /// the server cannot be reached.
+  /// This behavior can be altered via the [source] parameter.
+  Future<PlatformDocumentSnapshot> get(
+    String app, {
+    @required String path,
+    @required Source source,
+  }) {
+    return channel.invokeMapMethod<String, dynamic>(
+      'DocumentReference#get',
+      <String, dynamic>{
+        'app': app,
+        'path': path,
+        'source': getSourceString(source),
+      },
+    ).then((Map<String, dynamic> data) {
+      return PlatformDocumentSnapshot(
+          path: data['path'],
+          data: data['data']?.cast<String, dynamic>(),
+          metadata: PlatformSnapshotMetadata(
+              hasPendingWrites: data['metadata']['hasPendingWrites'],
+              isFromCache: data['metadata']['isFromCache'],
+            ),
+        );
+    });
+  }
+
+  /// Deletes the document referred to by this [path].
+  Future<void> delete(
+    String app, {
+    @required String path,
+  }) {
+    return channel.invokeMethod<void>(
+      'DocumentReference#delete',
+      <String, dynamic>{'app': app, 'path': path},
+    );
+  }
+
+  /// Writes [data] to the document referred to by this [path].
+  /// If the document does not yet exist, it will be created.
+  /// If you pass [options], the provided data can be merged into an existing document.
+  Future<void> set(
+    String app, {
+    @required String path,
+    Map<String, dynamic> data,
+    PlatformSetOptions options,
+  }) {
+    return channel.invokeMethod<void>(
+      'DocumentReference#setData',
+      <String, dynamic>{
+        'app': app,
+        'path': path,
+        'data': data,
+        'options': options.asMap(),
+      },
+    );
+  }
+
+  /// Updates [data] in the document referred to by this [path].
+  /// The update will fail if applied to a document that does not exist.
+  Future<void> update(
+    String app, {
+    @required String path,
+    Map<String, dynamic> data,
+  }) {
+    return channel.invokeMethod<void>(
+      'DocumentReference#updateData',
+      <String, dynamic>{
+        'app': app,
+        'path': path,
+        'data': data,
+      },
+    );
+  }
+
+  // Snapshots
+
+  static final Map<int, StreamController<PlatformDocumentSnapshot>> _documentSnapshotStreamControllers = <int, StreamController<PlatformDocumentSnapshot>>{};
+
+  /// A Stream of QuerySnapshots.
+  /// The snapshot stream is never-ending.
+  Stream<PlatformDocumentSnapshot> snapshots(
+    String app, {
+    @required String path,
+    bool includeMetadataChanges,
+  }) {
+    assert(includeMetadataChanges != null);
+    Future<int> _handle;
+    // It's fine to let the StreamController be garbage collected once all the
+    // subscribers have cancelled; this analyzer warning is safe to ignore.
+    StreamController<PlatformDocumentSnapshot> controller; // ignore: close_sinks
+    controller = StreamController<PlatformDocumentSnapshot>.broadcast(
+      onListen: () {
+        _handle = _addDocumentReferenceSnapshotListener(
+          app,
+          path: path,
+          includeMetadataChanges: includeMetadataChanges,
+        ).then<int>((dynamic result) => result);
+        _handle.then((int handle) {
+          _documentSnapshotStreamControllers[handle] = controller;
+        });
+      },
+      onCancel: () {
+        _handle.then((int handle) async {
+          await _removeListener(handle);
+          _documentSnapshotStreamControllers.remove(handle);
+        });
+      },
+    );
+    return controller.stream;
+  }
+
+  Future<int> _addDocumentReferenceSnapshotListener(
+    String app, {
+    @required String path,
+    bool includeMetadataChanges,
+  }) {
+    return channel.invokeMethod<int>(
+      'DocumentReference#addSnapshotListener',
+      <String, dynamic>{
+        'app': app,
+        'path': path,
+        'includeMetadataChanges': includeMetadataChanges,
+      },
+    );
+  }
+
+  Future<void> _removeListener(int handle) {
+    return channel.invokeMethod<void>(
+      'removeListener',
+      <String, dynamic>{'handle': handle},
+    );
+  }
+}
diff --git a/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/implementations/method_channel_firestore.dart b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/implementations/method_channel_firestore.dart
new file mode 100644
index 000000000000..8e43e54b019e
--- /dev/null
+++ b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/implementations/method_channel_firestore.dart
@@ -0,0 +1,85 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+import 'dart:async';
+
+import 'package:flutter/services.dart';
+import 'package:meta/meta.dart' show visibleForTesting;
+
+import './multi_method_channel.dart';
+import './method_channel_document_reference.dart';
+import './method_channel_query.dart';
+import './method_channel_transaction.dart';
+import './method_channel_write_batch.dart';
+
+import '../interfaces.dart';
+
+/// A method channel implementation of the Firestore platform.
+class MethodChannelFirestore extends FirestorePlatform {
+  /// Constructor. Requires a MethodCodec [codec] that can live in userland and have business logic there.
+  /// This class shouldn't be instantiated more than once per lifetime of the app, so we don't end up with
+  /// multiple subscriptions to the different channels!
+  MethodChannelFirestore(StandardMessageCodec codec) {
+    // Register all other instances...
+    MultiMethodChannel channel = MultiMethodChannel(
+      'plugins.flutter.io/cloud_firestore',
+      StandardMethodCodec(codec),
+    );
+    
+    MethodChannelFirestore._channel = channel;
+    DocumentReferencePlatform.instance = MethodChannelDocumentReference(channel);
+    QueryPlatform.instance = MethodChannelQuery(channel);
+    TransactionPlatform.instance = MethodChannelTransaction(channel);
+    WriteBatchPlatform.instance = MethodChannelWriteBatch(channel);
+  }
+
+  /// The MethodChannel used to pass messages to the native side.
+  @visibleForTesting
+  static MethodChannel get channel => MethodChannelFirestore._channel;
+  static MethodChannel _channel;
+
+  /// DocumentReference delegate
+  @override
+  DocumentReferencePlatform get documentReference =>
+      DocumentReferencePlatform.instance;
+
+  /// Query delegate
+  @override
+  QueryPlatform get query => QueryPlatform.instance;
+
+  /// Transaction delegate
+  @override
+  TransactionPlatform get transaction => TransactionPlatform.instance;
+
+  /// WriteBatch delegate
+  @override
+  WriteBatchPlatform get writeBatch => WriteBatchPlatform.instance;
+
+  @override
+  Future<void> enablePersistence(String app, {bool enable = true}) {
+    return channel
+        .invokeMethod<void>('Firestore#enablePersistence', <String, dynamic>{
+      'app': app,
+      'enable': enable,
+    });
+  }
+
+  @override
+  Future<void> settings(
+    String app, {
+    bool persistenceEnabled,
+    String host,
+    bool sslEnabled,
+    int cacheSizeBytes,
+  }) {
+    return channel.invokeMethod<void>('Firestore#settings', <String, dynamic>{
+      'app': app,
+      'persistenceEnabled': persistenceEnabled,
+      'host': host,
+      'sslEnabled': sslEnabled,
+      'cacheSizeBytes': cacheSizeBytes,
+    });
+  }
+
+  // Find runTransaction in transaction.run
+}
diff --git a/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/implementations/method_channel_query.dart b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/implementations/method_channel_query.dart
new file mode 100644
index 000000000000..d861ba4fe9a0
--- /dev/null
+++ b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/implementations/method_channel_query.dart
@@ -0,0 +1,117 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+import 'dart:async';
+
+import 'package:flutter/services.dart';
+import 'package:meta/meta.dart' show visibleForTesting, required;
+
+import './multi_method_channel.dart';
+
+import '../interfaces/query_platform.dart';
+import '../types.dart';
+
+class MethodChannelQuery extends QueryPlatform {
+  MethodChannelQuery(MultiMethodChannel channel) {
+    MethodChannelQuery._channel = channel;
+    MethodChannelQuery._channel.addMethodCallHandler('QuerySnapshot', this._handleQuerySnapshot);
+  }
+
+  @visibleForTesting
+  static MultiMethodChannel get channel => MethodChannelQuery._channel;
+  static MultiMethodChannel _channel;
+
+  void _handleQuerySnapshot(MethodCall call) {
+    final int handle = call.arguments['handle'];
+    _querySnapshotStreamControllers[handle].add(PlatformQuerySnapshot(data: call.arguments));
+  }
+
+  /// What does this method correspond to in the Firebase API?
+  Future<PlatformQuerySnapshot> getDocuments(
+    String app, {
+    @required String path,
+    bool isCollectionGroup,
+    Map<String, dynamic> parameters,
+    Source source,
+  }) {
+    return channel.invokeMapMethod<String, dynamic>(
+      'Query#getDocuments',
+      <String, dynamic>{
+        'app': app,
+        'path': path,
+        'isCollectionGroup': isCollectionGroup,
+        'parameters': parameters,
+        'source': getSourceString(source),
+      },
+    ).then((Map<String, dynamic> response) {
+      return PlatformQuerySnapshot(data: response);
+    });
+  }
+
+  // Snapshots
+
+  static final Map<int, StreamController<PlatformQuerySnapshot>> _querySnapshotStreamControllers = <int, StreamController<PlatformQuerySnapshot>>{};
+
+  /// A Stream of QuerySnapshots.
+  /// The snapshot stream is never-ending.
+  Stream<PlatformQuerySnapshot> snapshots(
+    String app, {
+    @required String path,
+    bool isCollectionGroup,
+    Map<String, dynamic> parameters,
+    bool includeMetadataChanges,
+  }) {
+    assert(includeMetadataChanges != null);
+    Future<int> _handle;
+    // It's fine to let the StreamController be garbage collected once all the
+    // subscribers have cancelled; this analyzer warning is safe to ignore.
+    StreamController<PlatformQuerySnapshot> controller; // ignore: close_sinks
+    controller = StreamController<PlatformQuerySnapshot>.broadcast(
+      onListen: () {
+        _handle = _addQuerySnapshotListener(
+          app,
+          path: path,
+          isCollectionGroup: isCollectionGroup,
+          parameters: parameters,
+          includeMetadataChanges: includeMetadataChanges,
+        ).then<int>((dynamic result) => result);
+        _handle.then((int handle) {
+          _querySnapshotStreamControllers[handle] = controller;
+        });
+      },
+      onCancel: () {
+        _handle.then((int handle) async {
+          await _removeListener(handle);
+          _querySnapshotStreamControllers.remove(handle);
+        });
+      },
+    );
+    return controller.stream;
+  }
+
+  Future<int> _addQuerySnapshotListener(
+    String app, {
+    @required String path,
+    bool isCollectionGroup,
+    Map<String, dynamic> parameters,
+    bool includeMetadataChanges,
+  }) {
+    return channel.invokeMethod<int>(
+      'Query#addSnapshotListener',
+      <String, dynamic>{
+        'app': app,
+        'path': path,
+        'isCollectionGroup': isCollectionGroup,
+        'parameters': parameters,
+        'includeMetadataChanges': includeMetadataChanges,
+      },
+    );
+  }
+
+  Future<void> _removeListener(int handle) {
+    return channel.invokeMethod<void>(
+      'removeListener',
+      <String, dynamic>{'handle': handle},
+    );
+  }
+}
diff --git a/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/implementations/method_channel_transaction.dart b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/implementations/method_channel_transaction.dart
new file mode 100644
index 000000000000..6828800cde47
--- /dev/null
+++ b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/implementations/method_channel_transaction.dart
@@ -0,0 +1,118 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+import 'dart:async';
+
+import 'package:flutter/services.dart';
+import 'package:meta/meta.dart' show required, visibleForTesting;
+
+import './multi_method_channel.dart';
+
+import '../interfaces/transaction_platform.dart';
+import '../types.dart';
+
+class MethodChannelTransaction extends TransactionPlatform {
+  MethodChannelTransaction(MultiMethodChannel channel) {
+    MethodChannelTransaction._channel = channel;
+    MethodChannelTransaction._channel.addMethodCallHandler('DoTransaction', this._handleDoTransaction);
+  }
+
+  @visibleForTesting
+  static MultiMethodChannel get channel => MethodChannelTransaction._channel;
+  static MultiMethodChannel _channel;
+
+  static final Map<int, PlatformTransactionHandler> _transactionHandlers =
+      <int, PlatformTransactionHandler>{};
+  static int _transactionHandlerId = 0;
+
+  Future<dynamic> _handleDoTransaction(MethodCall call) async {
+    final int transactionId = call.arguments['transactionId'];
+    // Do the transaction
+    final PlatformTransactionHandler handler = _transactionHandlers[transactionId];
+    return await handler(PlatformTransaction(transactionId: transactionId));
+  }
+
+  @override
+  Future<Map<String, dynamic>> run(
+    String app, {
+    @required PlatformTransactionHandler updateFunction,
+    int transactionTimeout,
+  }) async {
+    // The [updateFunction] will be used by the [_handleDoTransaction] method later
+    final int transactionId = _transactionHandlerId++;
+    _transactionHandlers[transactionId] = updateFunction;
+
+    return channel.invokeMapMethod<String, dynamic>(
+        'Firestore#runTransaction', <String, dynamic>{
+        'app': app,
+        'transactionId': transactionId,
+        'transactionTimeout': transactionTimeout
+      });
+  }
+
+  @override
+  Future<PlatformDocumentSnapshot> get(
+    String app, {
+    @required String path,
+    @required int transactionId,
+  }) {
+    return channel
+        .invokeMapMethod<String, dynamic>('Transaction#get', <String, dynamic>{
+          'app': app,
+          'transactionId': transactionId,
+          'path': path,
+        }).then((data) {
+          return PlatformDocumentSnapshot(
+              path: data['path'],
+              data: data['data']?.cast<String, dynamic>(),
+              metadata: PlatformSnapshotMetadata(
+                  hasPendingWrites: data['metadata']['hasPendingWrites'],
+                  isFromCache: data['metadata']['isFromCache'],
+                ),
+          );
+        });
+  }
+
+  @override
+  Future<void> delete(
+    String app, {
+    @required String path,
+    @required int transactionId,
+  }) {
+    return channel.invokeMethod<void>('Transaction#delete', <String, dynamic>{
+        'app': app,
+        'transactionId': transactionId,
+        'path': path,
+      });
+  }
+
+  @override
+  Future<void> update(
+    String app, {
+    @required String path,
+    @required int transactionId,
+    Map<String, dynamic> data,
+  }) async {
+    return channel.invokeMethod<void>('Transaction#update', <String, dynamic>{
+        'app': app,
+        'transactionId': transactionId,
+        'path': path,
+        'data': data,
+      });
+  }
+
+  @override
+  Future<void> set(
+    String app, {
+    @required String path,
+    @required int transactionId,
+    Map<String, dynamic> data,
+  }) async {
+    return channel.invokeMethod<void>('Transaction#set', <String, dynamic>{
+        'app': app,
+        'transactionId': transactionId,
+        'path': path,
+        'data': data,
+      });
+  }
+}
diff --git a/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/implementations/method_channel_write_batch.dart b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/implementations/method_channel_write_batch.dart
new file mode 100644
index 000000000000..bf7d1ef246b8
--- /dev/null
+++ b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/implementations/method_channel_write_batch.dart
@@ -0,0 +1,102 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+import 'dart:async';
+
+import 'package:meta/meta.dart' show required, visibleForTesting;
+
+import './multi_method_channel.dart';
+
+import '../types.dart';
+import '../interfaces/write_batch_platform.dart';
+
+class MethodChannelWriteBatch extends WriteBatchPlatform {
+  /// Constructor
+  MethodChannelWriteBatch(MultiMethodChannel channel) {
+    MethodChannelWriteBatch._channel = channel;
+  }
+
+  @visibleForTesting
+  static MultiMethodChannel get channel => MethodChannelWriteBatch._channel;
+  static MultiMethodChannel _channel;
+
+  /// Creates a new Write Batch
+  // Android returns a WriteBatch id int
+  @override
+  Future<PlatformWriteBatchHandle> create(String app) {
+    return channel.invokeMethod<dynamic>(
+        'WriteBatch#create', <String, dynamic>{'app': app}).then((id) => PlatformWriteBatchHandle(writeBatchId: id));
+  }
+
+  /// Commits all of the writes in this write batch as a single atomic unit.
+  /// Returns a Promise resolved once all of the writes in the batch have been
+  /// successfully written to the backend as an atomic unit.
+  /// Note that it won't resolve while you're offline.
+  @override
+  Future<void> commit({
+    @required PlatformWriteBatchHandle handle,
+  }) async {
+    return channel.invokeMethod<void>(
+        'WriteBatch#commit', <String, dynamic>{'handle': handle.writeBatchId});
+  }
+
+  /// Deletes the document referred to by the provided [handle] and [path].
+  @override
+  Future<void> delete(
+    String app, {
+    @required PlatformWriteBatchHandle handle,
+    @required String path,
+  }) async {
+    return channel.invokeMethod<void>(
+      'WriteBatch#delete',
+      <String, dynamic>{
+        'app': app,
+        'handle': handle.writeBatchId,
+        'path': path,
+      },
+    );
+  }
+
+  /// Writes to the document referred to by the provided [handle] and [path].
+  /// If the document does not exist yet, it will be created.
+  /// If you pass [options], the provided data can be merged into the existing document.
+  @override
+  Future<void> set(
+    String app, {
+    @required PlatformWriteBatchHandle handle,
+    @required String path,
+    Map<String, dynamic> data,
+    PlatformSetOptions options,
+  }) async {
+    return channel.invokeMethod<void>(
+      'WriteBatch#setData',
+      <String, dynamic>{
+        'app': app,
+        'handle': handle.writeBatchId,
+        'path': path,
+        'data': data,
+        'options': options.asMap(),
+      },
+    );
+  }
+
+  /// Updates [data] in the document referred to by the provided [handle] and [path].
+  /// The update will fail if applied to a document that does not exist.
+  @override
+  Future<void> update(
+    String app, {
+    @required PlatformWriteBatchHandle handle,
+    @required String path,
+    Map<String, dynamic> data,
+  }) async {
+    return channel.invokeMethod<void>(
+      'WriteBatch#updateData',
+      <String, dynamic>{
+        'app': app,
+        'handle': handle.writeBatchId,
+        'path': path,
+        'data': data,
+      },
+    );
+  }
+}
diff --git a/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/implementations/multi_method_channel.dart b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/implementations/multi_method_channel.dart
new file mode 100644
index 000000000000..09c8a3480fb1
--- /dev/null
+++ b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/implementations/multi_method_channel.dart
@@ -0,0 +1,35 @@
+import 'dart:async';
+
+import 'package:flutter/services.dart';
+
+typedef _MultiMethodChannelHandler(MethodCall call);
+
+class MultiMethodChannel extends MethodChannel {
+  MultiMethodChannel(name, [codec = const StandardMethodCodec(), BinaryMessenger binaryMessenger ])
+      : super(name, codec, binaryMessenger) {
+        // Register this as handler
+        super.setMethodCallHandler(_methodCallHandler);
+      }
+  
+  Map<String, _MultiMethodChannelHandler> _multiMethodChannelHandlers = <String, _MultiMethodChannelHandler>{};
+
+  Future<dynamic> _methodCallHandler(MethodCall call) {
+    _MultiMethodChannelHandler handler = _multiMethodChannelHandlers[call.method];
+    return (handler != null) ? handler(call) : null;
+  }
+
+  void addMethodCallHandler(String method, _MultiMethodChannelHandler handler) {
+    assert(!_multiMethodChannelHandlers.containsKey(method), 'A handler for method $method has already been registered!');
+    _multiMethodChannelHandlers[method] = handler;
+  }
+
+  void removeMethodCallHandler(String method) {
+    _multiMethodChannelHandlers.remove(method);
+  }
+
+  @override
+  @Deprecated('MultiMethodChannel doesn\'t support setMethodCallHandler, and will throw at runtime. Use addMethodCallHandler (or a base MethodChannel instead).')
+  void setMethodCallHandler(Future<dynamic> handler(MethodCall call)) {
+    throw UnsupportedError('MultiMethodChannel doesn\'t support setMethodCallHandler. Use addMethodCallHandler (or use a normal MethodChannel instead).');
+  }
+}
diff --git a/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/interfaces.dart b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/interfaces.dart
new file mode 100644
index 000000000000..b5869a274fbe
--- /dev/null
+++ b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/interfaces.dart
@@ -0,0 +1,9 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+export 'interfaces/document_reference_platform.dart';
+export 'interfaces/firestore_platform.dart';
+export 'interfaces/query_platform.dart';
+export 'interfaces/transaction_platform.dart';
+export 'interfaces/write_batch_platform.dart';
diff --git a/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/interfaces/document_reference_platform.dart b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/interfaces/document_reference_platform.dart
new file mode 100644
index 000000000000..4583c763e07c
--- /dev/null
+++ b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/interfaces/document_reference_platform.dart
@@ -0,0 +1,92 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+import 'dart:async';
+
+import 'package:meta/meta.dart' show required;
+import 'package:plugin_platform_interface/plugin_platform_interface.dart';
+
+import '../types.dart';
+
+/// The Document Reference platform interface.
+abstract class DocumentReferencePlatform extends PlatformInterface {
+  /// Constructor
+  DocumentReferencePlatform() : super(token: _token);
+
+  static final Object _token = Object();
+
+  /// The default instance of [DocumentReferencePlatform] to use.
+  ///
+  /// Platform-specific plugins should override this with their own class
+  /// that extends [DocumentReferencePlatform] when they register themselves.
+  static DocumentReferencePlatform get instance => _instance;
+
+  static DocumentReferencePlatform _instance;
+
+  // TODO(amirh): Extract common platform interface logic.
+  // https://github.com/flutter/flutter/issues/43368
+  static set instance(DocumentReferencePlatform instance) {
+    PlatformInterface.verifyToken(instance, _token);
+    _instance = instance;
+  }
+
+  // Actual interface
+
+  /// A Stream of Document Snapshots.
+  /// The snapshot stream is never-ending.
+  Stream<PlatformDocumentSnapshot> snapshots(
+    String app, {
+    @required String path,
+    bool includeMetadataChanges,
+  }) {
+    throw UnimplementedError(
+        'DocumentReferencePlatform::snapshots() is not implemented');
+  }
+
+  /// Reads the document referred to by this [path].
+  /// By default, get() attempts to provide up-to-date data when possible by waiting for
+  /// data from the server, but it may return cached data or fail if you are offline and
+  /// the server cannot be reached.
+  /// This behavior can be altered via the [source] parameter.
+  Future<PlatformDocumentSnapshot> get(
+    String app, {
+    @required String path,
+    @required Source source,
+  }) async {
+    throw UnimplementedError(
+        'DocumentReferencePlatform::get() is not implemented');
+  }
+
+  /// Deletes the document referred to by this [path].
+  Future<void> delete(
+    String app, {
+    @required String path,
+  }) async {
+    throw UnimplementedError(
+        'DocumentReferencePlatform::delete() is not implemented');
+  }
+
+  /// Writes [data] to the document referred to by this [path].
+  /// If the document does not yet exist, it will be created.
+  /// If you pass [options], the provided data can be merged into an existing document.
+  Future<void> set(
+    String app, {
+    @required String path,
+    Map<String, dynamic> data,
+    PlatformSetOptions options,
+  }) async {
+    throw UnimplementedError(
+        'DocumentReferencePlatform::set() is not implemented');
+  }
+
+  /// Updates [data] in the document referred to by this [path].
+  /// The update will fail if applied to a document that does not exist.
+  Future<void> update(
+    String app, {
+    @required String path,
+    Map<String, dynamic> data,
+  }) async {
+    throw UnimplementedError(
+        'DocumentReferencePlatform::update() is not implemented');
+  }
+}
diff --git a/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/interfaces/firestore_platform.dart b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/interfaces/firestore_platform.dart
new file mode 100644
index 000000000000..d81c994535ee
--- /dev/null
+++ b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/interfaces/firestore_platform.dart
@@ -0,0 +1,80 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+import 'dart:async';
+
+import 'package:meta/meta.dart' show required;
+import 'package:plugin_platform_interface/plugin_platform_interface.dart';
+
+import './document_reference_platform.dart';
+import './query_platform.dart';
+import './transaction_platform.dart';
+import './write_batch_platform.dart';
+
+/// The Firestore platform interface.
+abstract class FirestorePlatform extends PlatformInterface {
+  /// Constructor
+  FirestorePlatform() : super(token: _token);
+
+  static final Object _token = Object();
+
+  /// The default instance of [FirestorePlatform] to use.
+  ///
+  /// Platform-specific plugins should override this with their own class
+  /// that extends [FirestorePlatform] when they register themselves.
+  static FirestorePlatform get instance => _instance;
+
+  static FirestorePlatform _instance;
+
+  // TODO(amirh): Extract common platform interface logic.
+  // https://github.com/flutter/flutter/issues/43368
+  static set instance(FirestorePlatform instance) {
+    PlatformInterface.verifyToken(instance, _token);
+    _instance = instance;
+  }
+
+  // Delegate platforms that need to be initialized at construction time
+  /// DocumentReference delegate
+  DocumentReferencePlatform get documentReference {
+    throw UnimplementedError(
+        'Provide a DocumentReferencePlatform on your implementation.');
+  }
+
+  /// Query delegate
+  QueryPlatform get query {
+    throw UnimplementedError('Provide a QueryPlatform on your implementation.');
+  }
+
+  /// Transaction delegate
+  TransactionPlatform get transaction {
+    throw UnimplementedError(
+        'Provide a TransactionPlatform on your implementation.');
+  }
+
+  /// WriteBatch delegate
+  WriteBatchPlatform get writeBatch {
+    throw UnimplementedError(
+        'Provide a WriteBatchPlatform on your implementation.');
+  }
+
+  /// Specifies custom settings to be used to configure the Firestore instance.
+  /// Must be set before invoking any other methods.
+  Future<void> settings(
+    String app, {
+    bool persistenceEnabled,
+    String host,
+    bool sslEnabled,
+    int cacheSizeBytes,
+  }) async {
+    throw UnimplementedError(
+        'FirestorePlatform::settings() is not implemented');
+  }
+
+  // Actual interface
+  /// Attempts to enable persistent storage, if possible.
+  /// Must be called before any other methods (other than [settings]).
+  Future<void> enablePersistence(String app, {@required bool enable}) async {
+    throw UnimplementedError(
+        'FirestorePlatform::enablePersistence() is not implemented');
+  }
+}
diff --git a/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/interfaces/query_platform.dart b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/interfaces/query_platform.dart
new file mode 100644
index 000000000000..0346c5b6992d
--- /dev/null
+++ b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/interfaces/query_platform.dart
@@ -0,0 +1,60 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+import 'dart:async';
+
+import 'package:meta/meta.dart' show required;
+import 'package:plugin_platform_interface/plugin_platform_interface.dart';
+
+import '../types.dart';
+
+/// The Query platform interface.
+abstract class QueryPlatform extends PlatformInterface {
+  /// Constructor
+  QueryPlatform() : super(token: _token);
+
+  static final Object _token = Object();
+
+  /// The default instance of [QueryPlatform] to use.
+  ///
+  /// Platform-specific plugins should override this with their own class
+  /// that extends [QueryPlatform] when they register themselves.
+  static QueryPlatform get instance => _instance;
+
+  static QueryPlatform _instance;
+
+  // TODO(amirh): Extract common platform interface logic.
+  // https://github.com/flutter/flutter/issues/43368
+  static set instance(QueryPlatform instance) {
+    PlatformInterface.verifyToken(instance, _token);
+    _instance = instance;
+  }
+
+  // Actual interface
+
+  /// A Stream of QuerySnapshots.
+  /// The snapshot stream is never-ending.
+  // TODO(ditman): Type the return of this Stream (PlatformQuerySnapshot?)
+  Stream<PlatformQuerySnapshot> snapshots(
+    String app, {
+    @required String path,
+    bool isCollectionGroup,
+    Map<String, dynamic> parameters,
+    bool includeMetadataChanges,
+  }) {
+    throw UnimplementedError('QueryPlatform::snapshots() is not implemented');
+  }
+
+  /// What does this method correspond to in the Firebase API?
+  // TODO(ditman): Type this return (PlatformQueryDocument?)
+  Future<PlatformQuerySnapshot> getDocuments(
+    String app, {
+    @required String path,
+    bool isCollectionGroup,
+    Map<String, dynamic> parameters,
+    Source source,
+  }) async {
+    throw UnimplementedError(
+        'QueryPlatform::getDocuments() is not implemented');
+  }
+}
diff --git a/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/interfaces/transaction_platform.dart b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/interfaces/transaction_platform.dart
new file mode 100644
index 000000000000..9f5aa639bfcc
--- /dev/null
+++ b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/interfaces/transaction_platform.dart
@@ -0,0 +1,90 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+import 'dart:async';
+
+import 'package:meta/meta.dart' show required;
+import 'package:plugin_platform_interface/plugin_platform_interface.dart';
+
+import '../types.dart';
+
+/// The Transaction platform interface.
+abstract class TransactionPlatform extends PlatformInterface {
+  /// Constructor
+  TransactionPlatform() : super(token: _token);
+
+  static final Object _token = Object();
+
+  /// The default instance of [TransactionPlatform] to use.
+  ///
+  /// Platform-specific plugins should override this with their own class
+  /// that extends [TransactionPlatform] when they register themselves.
+  static TransactionPlatform get instance => _instance;
+
+  static TransactionPlatform _instance;
+
+  // TODO(amirh): Extract common platform interface logic.
+  // https://github.com/flutter/flutter/issues/43368
+  static set instance(TransactionPlatform instance) {
+    PlatformInterface.verifyToken(instance, _token);
+    _instance = instance;
+  }
+
+  // Actual interface
+
+  /// Executes the given [updateFunction] and then attempts to commit the changes applied within the transaction.
+  /// If any document read within the transaction has changed, Firestore retries the updateFunction.
+  /// If it fails to commit after 5 attempts, the transaction fails.
+  ///
+  /// If the transaction completed successfully or was explicitly aborted (the updateFunction returned a failed promise),
+  /// the promise returned by the updateFunction is returned here.
+  /// Else, if the transaction failed, a rejected promise with the corresponding failure error will be returned.
+  // TODO(ditman): What's the type of this return?
+  Future<Map<String, dynamic>> run(
+    String app, {
+    @required PlatformTransactionHandler updateFunction,
+    int transactionTimeout,
+  }) async {
+    throw UnimplementedError('TransactionPlatform::run() is not implemented');
+  }
+
+  /// Reads the transaction referenced by the provided [transactionId].
+  Future<PlatformDocumentSnapshot> get(
+    String app, {
+    @required String path,
+    @required int transactionId,
+  }) async {
+    throw UnimplementedError('TransactionPlatform::get() is not implemented');
+  }
+
+  /// Deletes the transaction referred to by the provided [transactionId].
+  Future<void> delete(
+    String app, {
+    @required String path,
+    @required int transactionId,
+  }) async {
+    throw UnimplementedError(
+        'TransactionPlatform::delete() is not implemented');
+  }
+
+  /// Updates fields with [data] in the transaction referred to by the provided [transactionId].
+  Future<void> update(
+    String app, {
+    @required String path,
+    @required int transactionId,
+    Map<String, dynamic> data,
+  }) async {
+    throw UnimplementedError(
+        'TransactionPlatform::update() is not implemented');
+  }
+
+  /// Writes to the transaction referred to by the provided [transactionId].
+  Future<void> set(
+    String app, {
+    @required String path,
+    @required int transactionId,
+    Map<String, dynamic> data,
+  }) async {
+    throw UnimplementedError('TransactionPlatform::set() is not implemented');
+  }
+}
diff --git a/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/interfaces/write_batch_platform.dart b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/interfaces/write_batch_platform.dart
new file mode 100644
index 000000000000..4b362d5a8fac
--- /dev/null
+++ b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/interfaces/write_batch_platform.dart
@@ -0,0 +1,82 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+import 'dart:async';
+
+import 'package:meta/meta.dart' show required;
+import 'package:plugin_platform_interface/plugin_platform_interface.dart';
+
+import '../types.dart';
+
+/// The WriteBatch platform interface.
+abstract class WriteBatchPlatform extends PlatformInterface {
+  /// Constructor
+  WriteBatchPlatform() : super(token: _token);
+
+  static final Object _token = Object();
+
+  /// The default instance of [WriteBatchPlatform] to use.
+  ///
+  /// Platform-specific plugins should override this with their own class
+  /// that extends [WriteBatchPlatform] when they register themselves.
+  static WriteBatchPlatform get instance => _instance;
+
+  static WriteBatchPlatform _instance;
+
+  // TODO(amirh): Extract common platform interface logic.
+  // https://github.com/flutter/flutter/issues/43368
+  static set instance(WriteBatchPlatform instance) {
+    PlatformInterface.verifyToken(instance, _token);
+    _instance = instance;
+  }
+
+  // Actual interface
+  /// Creates a new Write Batch
+  // Android returns a WriteBatch id int
+  Future<PlatformWriteBatchHandle> create(String app) async {
+    throw UnimplementedError('WriteBatchPlatform::create() is not implemented');
+  }
+
+  /// Commits all of the writes in this write batch as a single atomic unit.
+  /// Returns a Promise resolved once all of the writes in the batch have been
+  /// successfully written to the backend as an atomic unit.
+  /// Note that it won't resolve while you're offline.
+  Future<void> commit({
+    @required PlatformWriteBatchHandle handle,
+  }) async {
+    throw UnimplementedError('WriteBatchPlatform::commit() is not implemented');
+  }
+
+  /// Deletes the document referred to by the provided [handle] and [path].
+  Future<void> delete(
+    String app, {
+    @required PlatformWriteBatchHandle handle,
+    @required String path,
+  }) async {
+    throw UnimplementedError('WriteBatchPlatform::delete() is not implemented');
+  }
+
+  /// Writes to the document referred to by the provided [handle] and [path].
+  /// If the document does not exist yet, it will be created.
+  /// If you pass [options], the provided data can be merged into the existing document.
+  Future<void> set(
+    String app, {
+    @required PlatformWriteBatchHandle handle,
+    @required String path,
+    Map<String, dynamic> data,
+    PlatformSetOptions options,
+  }) async {
+    throw UnimplementedError('WriteBatchPlatform::set() is not implemented');
+  }
+
+  /// Updates [data] in the document referred to by the provided [handle] and [path].
+  /// The update will fail if applied to a document that does not exist.
+  Future<void> update(
+    String app, {
+    @required PlatformWriteBatchHandle handle,
+    @required String path,
+    Map<String, dynamic> data,
+  }) async {
+    throw UnimplementedError('WriteBatchPlatform::update() is not implemented');
+  }
+}
diff --git a/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/types.dart b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/types.dart
new file mode 100644
index 000000000000..9dcd6b8b082c
--- /dev/null
+++ b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/types.dart
@@ -0,0 +1,10 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+export 'types/document.dart';
+export 'types/query.dart';
+export 'types/set_options.dart';
+export 'types/source.dart';
+export 'types/transaction.dart';
+export 'types/write_batch.dart';
diff --git a/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/types/document.dart b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/types/document.dart
new file mode 100644
index 000000000000..c43d38569474
--- /dev/null
+++ b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/types/document.dart
@@ -0,0 +1,30 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+class PlatformDocumentSnapshot {
+  PlatformDocumentSnapshot({this.path, this.data, this.metadata});
+  String path;
+  Map<String, dynamic> data;
+  PlatformSnapshotMetadata metadata;
+
+  Map<String, dynamic> asMap() {
+    return <String, dynamic> {
+      'data': data,
+      'metadata': metadata.asMap(),
+    };
+  }
+}
+
+class PlatformSnapshotMetadata {
+  PlatformSnapshotMetadata({this.hasPendingWrites, this.isFromCache});
+  bool hasPendingWrites;
+  bool isFromCache;
+
+  Map<String, dynamic> asMap() {
+    return <String, dynamic> {
+      'hasPendingWrites': hasPendingWrites,
+      'isFromCache': isFromCache,
+    };
+  }
+}
diff --git a/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/types/query.dart b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/types/query.dart
new file mode 100644
index 000000000000..b4db8182971c
--- /dev/null
+++ b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/types/query.dart
@@ -0,0 +1,11 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// TODO: this needs to be more precise
+class PlatformQuerySnapshot {
+  PlatformQuerySnapshot({this.data});
+  Map<dynamic, dynamic> data;
+
+  Map<dynamic, dynamic> asMap() => data;
+}
diff --git a/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/types/set_options.dart b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/types/set_options.dart
new file mode 100644
index 000000000000..f2fab77b343d
--- /dev/null
+++ b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/types/set_options.dart
@@ -0,0 +1,21 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+/// An options object that configures the behavior of set() calls in DocumentReference, WriteBatch and Transaction.
+/// These calls can be configured to perform granular merges instead of overwriting the target documents in their
+/// entirety by providing a SetOptions with merge: true.
+class PlatformSetOptions {
+  /// Constructor
+  PlatformSetOptions({this.merge});
+
+  /// Changes the behavior of a set() call to only replace the values specified in its data argument.
+  /// Fields omitted from the set() call remain untouched.
+  bool merge;
+
+  Map<String, dynamic> asMap() {
+    return <String, dynamic> {
+      'merge': merge,
+    };
+  }
+}
diff --git a/packages/cloud_firestore/cloud_firestore/lib/src/source.dart b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/types/source.dart
similarity index 81%
rename from packages/cloud_firestore/cloud_firestore/lib/src/source.dart
rename to packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/types/source.dart
index 0a0a43eef8f3..9542dd25fb3f 100644
--- a/packages/cloud_firestore/cloud_firestore/lib/src/source.dart
+++ b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/types/source.dart
@@ -1,8 +1,6 @@
-// Copyright 2017, the Chromium project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-part of cloud_firestore;
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
 
 /// An enumeration of firestore source types.
 enum Source {
@@ -25,7 +23,7 @@ enum Source {
 }
 
 /// Converts [Source] to [String]
-String _getSourceString(Source source) {
+String getSourceString(Source source) {
   assert(source != null);
   if (source == Source.server) {
     return 'server';
@@ -35,3 +33,4 @@ String _getSourceString(Source source) {
   }
   return 'default';
 }
+
diff --git a/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/types/transaction.dart b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/types/transaction.dart
new file mode 100644
index 000000000000..9deebceb7ecf
--- /dev/null
+++ b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/types/transaction.dart
@@ -0,0 +1,10 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+class PlatformTransaction {
+  PlatformTransaction({this.transactionId});
+  int transactionId;
+}
+
+typedef Future<dynamic> PlatformTransactionHandler(PlatformTransaction transaction);
diff --git a/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/types/write_batch.dart b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/types/write_batch.dart
new file mode 100644
index 000000000000..96728a824109
--- /dev/null
+++ b/packages/cloud_firestore/cloud_firestore_platform_interface/lib/src/types/write_batch.dart
@@ -0,0 +1,8 @@
+// Copyright 2019 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+class PlatformWriteBatchHandle {
+  PlatformWriteBatchHandle({this.writeBatchId});
+  int writeBatchId;
+}
diff --git a/packages/cloud_firestore/cloud_firestore_platform_interface/pubspec.yaml b/packages/cloud_firestore/cloud_firestore_platform_interface/pubspec.yaml
new file mode 100644
index 000000000000..dbffc9681458
--- /dev/null
+++ b/packages/cloud_firestore/cloud_firestore_platform_interface/pubspec.yaml
@@ -0,0 +1,21 @@
+name: cloud_firestore_platform_interface
+description: A common platform interface for the cloud_firestore plugin.
+homepage: https://github.com/FirebaseExtended/flutterfire/tree/master/packages/cloud_firestore/cloud_firestore_platform_interface
+# NOTE: We strongly prefer non-breaking changes, even at the expense of a
+# less-clean API. See https://flutter.dev/go/platform-interface-breaking-changes
+version: 1.1.2
+
+dependencies:
+  flutter:
+    sdk: flutter
+  meta: ^1.0.5
+  plugin_platform_interface: ^1.0.0
+
+dev_dependencies:
+  flutter_test:
+    sdk: flutter
+  mockito: ^4.1.1
+
+environment:
+  sdk: ">=2.0.0-dev.28.0 <3.0.0"
+  flutter: ">=1.12.13+hotfix.4 <2.0.0"