feat(firestore): add support for Pipeline APIs

packages/cloud_firestore/cloud_firestore/ios/cloud_firestore/Sources/cloud_firestore/FirestoreMessages.g.m

@@ -5,8 +5,6 @@
 // See also: https://pub.dev/packages/pigeon
 
 #import "FirestoreMessages.g.h"
-#import "FLTFirebaseFirestoreReader.h"
-#import "FLTFirebaseFirestoreWriter.h"
 
 #if TARGET_OS_OSX
 #import <FlutterMacOS/FlutterMacOS.h>
@@ -168,6 +166,18 @@ + (nullable PigeonQuerySnapshot *)nullableFromList:(NSArray *)list;
 - (NSArray *)toList;
 @end
 
+@interface PigeonPipelineResult ()
++ (PigeonPipelineResult *)fromList:(NSArray *)list;
++ (nullable PigeonPipelineResult *)nullableFromList:(NSArray *)list;
+- (NSArray *)toList;
+@end
+
+@interface PigeonPipelineSnapshot ()
++ (PigeonPipelineSnapshot *)fromList:(NSArray *)list;
++ (nullable PigeonPipelineSnapshot *)nullableFromList:(NSArray *)list;
+- (NSArray *)toList;
+@end
+
 @interface PigeonGetOptions ()
 + (PigeonGetOptions *)fromList:(NSArray *)list;
 + (nullable PigeonGetOptions *)nullableFromList:(NSArray *)list;
@@ -349,7 +359,7 @@ + (instancetype)makeWithType:(DocumentChangeType)type
   pigeonResult.type = type;
   pigeonResult.document = document;
   pigeonResult.oldIndex = oldIndex;
-  pigeonResult.index = newIndex;
+  pigeonResult.newIndex = newIndex;
   return pigeonResult;
 }
 + (PigeonDocumentChange *)fromList:(NSArray *)list {
@@ -360,8 +370,8 @@ + (PigeonDocumentChange *)fromList:(NSArray *)list {
   NSAssert(pigeonResult.document != nil, @"");
   pigeonResult.oldIndex = GetNullableObjectAtIndex(list, 2);
   NSAssert(pigeonResult.oldIndex != nil, @"");
-  pigeonResult.index = GetNullableObjectAtIndex(list, 3);
-  NSAssert(pigeonResult.index != nil, @"");
+  pigeonResult.newIndex = GetNullableObjectAtIndex(list, 3);
+  NSAssert(pigeonResult.newIndex != nil, @"");
   return pigeonResult;
 }
 + (nullable PigeonDocumentChange *)nullableFromList:(NSArray *)list {
@@ -372,7 +382,7 @@ - (NSArray *)toList {
     @(self.type),
     (self.document ? [self.document toList] : [NSNull null]),
     (self.oldIndex ?: [NSNull null]),
-    (self.index ?: [NSNull null]),
+    (self.newIndex ?: [NSNull null]),
   ];
 }
 @end
@@ -410,6 +420,65 @@ - (NSArray *)toList {
 }
 @end
 
+@implementation PigeonPipelineResult
++ (instancetype)makeWithDocumentPath:(NSString *)documentPath
+                          createTime:(NSNumber *)createTime
+                          updateTime:(NSNumber *)updateTime {
+  PigeonPipelineResult *pigeonResult = [[PigeonPipelineResult alloc] init];
+  pigeonResult.documentPath = documentPath;
+  pigeonResult.createTime = createTime;
+  pigeonResult.updateTime = updateTime;
+  return pigeonResult;
+}
++ (PigeonPipelineResult *)fromList:(NSArray *)list {
+  PigeonPipelineResult *pigeonResult = [[PigeonPipelineResult alloc] init];
+  pigeonResult.documentPath = GetNullableObjectAtIndex(list, 0);
+  NSAssert(pigeonResult.documentPath != nil, @"");
+  pigeonResult.createTime = GetNullableObjectAtIndex(list, 1);
+  NSAssert(pigeonResult.createTime != nil, @"");
+  pigeonResult.updateTime = GetNullableObjectAtIndex(list, 2);
+  NSAssert(pigeonResult.updateTime != nil, @"");
+  return pigeonResult;
+}
++ (nullable PigeonPipelineResult *)nullableFromList:(NSArray *)list {
+  return (list) ? [PigeonPipelineResult fromList:list] : nil;
+}
+- (NSArray *)toList {
+  return @[
+    (self.documentPath ?: [NSNull null]),
+    (self.createTime ?: [NSNull null]),
+    (self.updateTime ?: [NSNull null]),
+  ];
+}
+@end
+
+@implementation PigeonPipelineSnapshot
++ (instancetype)makeWithResults:(NSArray<PigeonPipelineResult *> *)results
+                  executionTime:(NSNumber *)executionTime {
+  PigeonPipelineSnapshot *pigeonResult = [[PigeonPipelineSnapshot alloc] init];
+  pigeonResult.results = results;
+  pigeonResult.executionTime = executionTime;
+  return pigeonResult;
+}
++ (PigeonPipelineSnapshot *)fromList:(NSArray *)list {
+  PigeonPipelineSnapshot *pigeonResult = [[PigeonPipelineSnapshot alloc] init];
+  pigeonResult.results = GetNullableObjectAtIndex(list, 0);
+  NSAssert(pigeonResult.results != nil, @"");
+  pigeonResult.executionTime = GetNullableObjectAtIndex(list, 1);
+  NSAssert(pigeonResult.executionTime != nil, @"");
+  return pigeonResult;
+}
++ (nullable PigeonPipelineSnapshot *)nullableFromList:(NSArray *)list {
+  return (list) ? [PigeonPipelineSnapshot fromList:list] : nil;
+}
+- (NSArray *)toList {
+  return @[
+    (self.results ?: [NSNull null]),
+    (self.executionTime ?: [NSNull null]),
+  ];
+}
+@end
+
 @implementation PigeonGetOptions
 + (instancetype)makeWithSource:(Source)source
        serverTimestampBehavior:(ServerTimestampBehavior)serverTimestampBehavior {
@@ -649,7 +718,7 @@ - (NSArray *)toList {
 }
 @end
 
-@interface FirebaseFirestoreHostApiCodecReader : FLTFirebaseFirestoreReader
+@interface FirebaseFirestoreHostApiCodecReader : FlutterStandardReader
 @end
 @implementation FirebaseFirestoreHostApiCodecReader
 - (nullable id)readValueOfType:(UInt8)type {
@@ -673,20 +742,24 @@ - (nullable id)readValueOfType:(UInt8)type {
     case 136:
       return [PigeonGetOptions fromList:[self readValue]];
     case 137:
-      return [PigeonQueryParameters fromList:[self readValue]];
+      return [PigeonPipelineResult fromList:[self readValue]];
     case 138:
-      return [PigeonQuerySnapshot fromList:[self readValue]];
+      return [PigeonPipelineSnapshot fromList:[self readValue]];
     case 139:
-      return [PigeonSnapshotMetadata fromList:[self readValue]];
+      return [PigeonQueryParameters fromList:[self readValue]];
     case 140:
+      return [PigeonQuerySnapshot fromList:[self readValue]];
+    case 141:
+      return [PigeonSnapshotMetadata fromList:[self readValue]];
+    case 142:
       return [PigeonTransactionCommand fromList:[self readValue]];
     default:
       return [super readValueOfType:type];
   }
 }
 @end
 
-@interface FirebaseFirestoreHostApiCodecWriter : FLTFirebaseFirestoreWriter
+@interface FirebaseFirestoreHostApiCodecWriter : FlutterStandardWriter
 @end
 @implementation FirebaseFirestoreHostApiCodecWriter
 - (void)writeValue:(id)value {
@@ -717,18 +790,24 @@ - (void)writeValue:(id)value {
   } else if ([value isKindOfClass:[PigeonGetOptions class]]) {
     [self writeByte:136];
     [self writeValue:[value toList]];
-  } else if ([value isKindOfClass:[PigeonQueryParameters class]]) {
+  } else if ([value isKindOfClass:[PigeonPipelineResult class]]) {
     [self writeByte:137];
     [self writeValue:[value toList]];
-  } else if ([value isKindOfClass:[PigeonQuerySnapshot class]]) {
+  } else if ([value isKindOfClass:[PigeonPipelineSnapshot class]]) {
     [self writeByte:138];
     [self writeValue:[value toList]];
-  } else if ([value isKindOfClass:[PigeonSnapshotMetadata class]]) {
+  } else if ([value isKindOfClass:[PigeonQueryParameters class]]) {
     [self writeByte:139];
     [self writeValue:[value toList]];
-  } else if ([value isKindOfClass:[PigeonTransactionCommand class]]) {
+  } else if ([value isKindOfClass:[PigeonQuerySnapshot class]]) {
     [self writeByte:140];
     [self writeValue:[value toList]];
+  } else if ([value isKindOfClass:[PigeonSnapshotMetadata class]]) {
+    [self writeByte:141];
+    [self writeValue:[value toList]];
+  } else if ([value isKindOfClass:[PigeonTransactionCommand class]]) {
+    [self writeByte:142];
+    [self writeValue:[value toList]];
   } else {
     [super writeValue:value];
   }
@@ -1379,4 +1458,32 @@ void FirebaseFirestoreHostApiSetup(id<FlutterBinaryMessenger> binaryMessenger,
       [channel setMessageHandler:nil];
     }
   }
+  {
+    FlutterBasicMessageChannel *channel = [[FlutterBasicMessageChannel alloc]
+           initWithName:@"dev.flutter.pigeon.cloud_firestore_platform_interface."
+                        @"FirebaseFirestoreHostApi.executePipeline"
+        binaryMessenger:binaryMessenger
+                  codec:FirebaseFirestoreHostApiGetCodec()];
+    if (api) {
+      NSCAssert([api respondsToSelector:@selector(executePipelineApp:stages:options:completion:)],
+                @"FirebaseFirestoreHostApi api (%@) doesn't respond to "
+                @"@selector(executePipelineApp:stages:options:completion:)",
+                api);
+      [channel setMessageHandler:^(id _Nullable message, FlutterReply callback) {
+        NSArray *args = message;
+        FirestorePigeonFirebaseApp *arg_app = GetNullableObjectAtIndex(args, 0);
+        NSArray<NSDictionary<NSString *, id> *> *arg_stages = GetNullableObjectAtIndex(args, 1);
+        NSDictionary<NSString *, id> *arg_options = GetNullableObjectAtIndex(args, 2);
+        [api executePipelineApp:arg_app
+                         stages:arg_stages
+                        options:arg_options
+                     completion:^(PigeonPipelineSnapshot *_Nullable output,
+                                  FlutterError *_Nullable error) {
+                       callback(wrapResult(output, error));
+                     }];
+      }];
+    } else {
+      [channel setMessageHandler:nil];
+    }
+  }
 }

packages/cloud_firestore/cloud_firestore/ios/cloud_firestore/Sources/cloud_firestore/include/cloud_firestore/Public/FirestoreMessages.g.h

@@ -165,6 +165,8 @@ typedef NS_ENUM(NSUInteger, AggregateType) {
 @class PigeonDocumentSnapshot;
 @class PigeonDocumentChange;
 @class PigeonQuerySnapshot;
+@class PigeonPipelineResult;
+@class PigeonPipelineSnapshot;
 @class PigeonGetOptions;
 @class PigeonDocumentOption;
 @class PigeonTransactionCommand;
@@ -229,7 +231,7 @@ typedef NS_ENUM(NSUInteger, AggregateType) {
 @property(nonatomic, assign) DocumentChangeType type;
 @property(nonatomic, strong) PigeonDocumentSnapshot *document;
 @property(nonatomic, strong) NSNumber *oldIndex;
-@property(nonatomic, strong) NSNumber *index;
+@property(nonatomic, strong) NSNumber *newIndex;
 @end
 
 @interface PigeonQuerySnapshot : NSObject
@@ -243,6 +245,26 @@ typedef NS_ENUM(NSUInteger, AggregateType) {
 @property(nonatomic, strong) PigeonSnapshotMetadata *metadata;
 @end
 
+@interface PigeonPipelineResult : NSObject
+/// `init` unavailable to enforce nonnull fields, see the `make` class method.
+- (instancetype)init NS_UNAVAILABLE;
++ (instancetype)makeWithDocumentPath:(NSString *)documentPath
+                          createTime:(NSNumber *)createTime
+                          updateTime:(NSNumber *)updateTime;
+@property(nonatomic, copy) NSString *documentPath;
+@property(nonatomic, strong) NSNumber *createTime;
+@property(nonatomic, strong) NSNumber *updateTime;
+@end
+
+@interface PigeonPipelineSnapshot : NSObject
+/// `init` unavailable to enforce nonnull fields, see the `make` class method.
+- (instancetype)init NS_UNAVAILABLE;
++ (instancetype)makeWithResults:(NSArray<PigeonPipelineResult *> *)results
+                  executionTime:(NSNumber *)executionTime;
+@property(nonatomic, strong) NSArray<PigeonPipelineResult *> *results;
+@property(nonatomic, strong) NSNumber *executionTime;
+@end
+
 @interface PigeonGetOptions : NSObject
 /// `init` unavailable to enforce nonnull fields, see the `make` class method.
 - (instancetype)init NS_UNAVAILABLE;
@@ -416,6 +438,11 @@ NSObject<FlutterMessageCodec> *FirebaseFirestoreHostApiGetCodec(void);
 - (void)persistenceCacheIndexManagerRequestApp:(FirestorePigeonFirebaseApp *)app
                                        request:(PersistenceCacheIndexManagerRequest)request
                                     completion:(void (^)(FlutterError *_Nullable))completion;
+- (void)executePipelineApp:(FirestorePigeonFirebaseApp *)app
+                    stages:(NSArray<NSDictionary<NSString *, id> *> *)stages
+                   options:(nullable NSDictionary<NSString *, id> *)options
+                completion:(void (^)(PigeonPipelineSnapshot *_Nullable,
+                                     FlutterError *_Nullable))completion;
 @end
 
 extern void FirebaseFirestoreHostApiSetup(id<FlutterBinaryMessenger> binaryMessenger,

packages/cloud_firestore/cloud_firestore/lib/cloud_firestore.dart

@@ -53,7 +53,17 @@ part 'src/filters.dart';
 part 'src/firestore.dart';
 part 'src/load_bundle_task.dart';
 part 'src/load_bundle_task_snapshot.dart';
+part 'pipeline_snapshot.dart';
 part 'src/persistent_cache_index_manager.dart';
+part 'src/pipeline.dart';
+part 'src/pipeline_aggregate.dart';
+part 'src/pipeline_distance.dart';
+part 'src/pipeline_execute_options.dart';
+part 'src/pipeline_expression.dart';
+part 'src/pipeline_ordering.dart';
+part 'src/pipeline_sample.dart';
+part 'src/pipeline_source.dart';
+part 'src/pipeline_stage.dart';
 part 'src/query.dart';
 part 'src/query_document_snapshot.dart';
 part 'src/query_snapshot.dart';

packages/cloud_firestore/cloud_firestore/lib/pipeline_snapshot.dart

@@ -0,0 +1,26 @@
+// Copyright 2026, 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.dart';
+
+/// Result of executing a pipeline
+class PipelineResult {
+  final DocumentReference<Map<String, dynamic>> document;
+  final DateTime createTime;
+  final DateTime updateTime;
+
+  PipelineResult({
+    required this.document,
+    required this.createTime,
+    required this.updateTime,
+  });
+}
+
+/// Snapshot containing pipeline execution results
+class PipelineSnapshot {
+  final List<PipelineResult> result;
+  final DateTime executionTime;
+
+  PipelineSnapshot._(this.result, this.executionTime);
+}

packages/cloud_firestore/cloud_firestore/lib/src/firestore.dart

@@ -339,6 +339,26 @@ class FirebaseFirestore extends FirebasePluginPlatform {
     return null;
   }
 
+  /// Returns a [PipelineSource] for creating and executing pipelines.
+  ///
+  /// Pipelines allow you to perform complex queries and transformations on
+  /// Firestore data using a fluent API.
+  ///
+  /// Example:
+  /// ```dart
+  /// final snapshot = await FirebaseFirestore.instance
+  ///     .pipeline()
+  ///     .collection('users')
+  ///     .where(PipelineFilter(Field('age'), isGreaterThan: 18))
+  ///     .sort(Field('name').ascending())
+  ///     .limit(10)
+  ///     .execute();
+  /// ```
+  // ignore: use_to_and_as_if_applicable
+  PipelineSource pipeline() {
+    return PipelineSource._(this);
+  }
+
   /// Configures indexing for local query execution. Any previous index configuration is overridden.
   ///
   /// The index entries themselves are created asynchronously. You can continue to use queries that