diff --git a/pkg/front_end/testcases/general/ffi_sample.dart.weak.expect b/pkg/front_end/testcases/general/ffi_sample.dart.weak.expect
index d92782a30a51..269de2851d77 100644
--- a/pkg/front_end/testcases/general/ffi_sample.dart.weak.expect
+++ b/pkg/front_end/testcases/general/ffi_sample.dart.weak.expect
@@ -40,7 +40,7 @@ constants  {
 
 Constructor coverage from constants:
 org-dartlang-testcase:///ffi_sample.dart:
-- Double. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:114:9)
-- _NativeDouble. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:34:9)
+- Double. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:115:9)
+- _NativeDouble. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:35:9)
 - NativeType. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:12:9)
 - Object. (from org-dartlang-sdk:///sdk/lib/core/object.dart:25:9)
diff --git a/pkg/front_end/testcases/general/ffi_sample.dart.weak.modular.expect b/pkg/front_end/testcases/general/ffi_sample.dart.weak.modular.expect
index d92782a30a51..269de2851d77 100644
--- a/pkg/front_end/testcases/general/ffi_sample.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/general/ffi_sample.dart.weak.modular.expect
@@ -40,7 +40,7 @@ constants  {
 
 Constructor coverage from constants:
 org-dartlang-testcase:///ffi_sample.dart:
-- Double. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:114:9)
-- _NativeDouble. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:34:9)
+- Double. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:115:9)
+- _NativeDouble. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:35:9)
 - NativeType. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:12:9)
 - Object. (from org-dartlang-sdk:///sdk/lib/core/object.dart:25:9)
diff --git a/pkg/front_end/testcases/general/ffi_sample.dart.weak.transformed.expect b/pkg/front_end/testcases/general/ffi_sample.dart.weak.transformed.expect
index 0765c4c028cc..15587c98a7ee 100644
--- a/pkg/front_end/testcases/general/ffi_sample.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/general/ffi_sample.dart.weak.transformed.expect
@@ -74,7 +74,7 @@ constants  {
 
 Constructor coverage from constants:
 org-dartlang-testcase:///ffi_sample.dart:
-- Double. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:114:9)
-- _NativeDouble. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:34:9)
+- Double. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:115:9)
+- _NativeDouble. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:35:9)
 - NativeType. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:12:9)
 - Object. (from org-dartlang-sdk:///sdk/lib/core/object.dart:25:9)
diff --git a/pkg/front_end/testcases/nnbd/ffi_sample.dart.strong.expect b/pkg/front_end/testcases/nnbd/ffi_sample.dart.strong.expect
index b190b3a9c292..b376ba2c5873 100644
--- a/pkg/front_end/testcases/nnbd/ffi_sample.dart.strong.expect
+++ b/pkg/front_end/testcases/nnbd/ffi_sample.dart.strong.expect
@@ -34,7 +34,7 @@ constants  {
 
 Constructor coverage from constants:
 org-dartlang-testcase:///ffi_sample.dart:
-- Double. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:114:9)
-- _NativeDouble. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:34:9)
+- Double. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:115:9)
+- _NativeDouble. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:35:9)
 - NativeType. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:12:9)
 - Object. (from org-dartlang-sdk:///sdk/lib/core/object.dart:25:9)
diff --git a/pkg/front_end/testcases/nnbd/ffi_sample.dart.strong.transformed.expect b/pkg/front_end/testcases/nnbd/ffi_sample.dart.strong.transformed.expect
index fccf63463e32..2b681fae1d35 100644
--- a/pkg/front_end/testcases/nnbd/ffi_sample.dart.strong.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/ffi_sample.dart.strong.transformed.expect
@@ -65,7 +65,7 @@ constants  {
 
 Constructor coverage from constants:
 org-dartlang-testcase:///ffi_sample.dart:
-- Double. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:114:9)
-- _NativeDouble. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:34:9)
+- Double. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:115:9)
+- _NativeDouble. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:35:9)
 - NativeType. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:12:9)
 - Object. (from org-dartlang-sdk:///sdk/lib/core/object.dart:25:9)
diff --git a/pkg/front_end/testcases/nnbd/ffi_sample.dart.weak.expect b/pkg/front_end/testcases/nnbd/ffi_sample.dart.weak.expect
index b190b3a9c292..b376ba2c5873 100644
--- a/pkg/front_end/testcases/nnbd/ffi_sample.dart.weak.expect
+++ b/pkg/front_end/testcases/nnbd/ffi_sample.dart.weak.expect
@@ -34,7 +34,7 @@ constants  {
 
 Constructor coverage from constants:
 org-dartlang-testcase:///ffi_sample.dart:
-- Double. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:114:9)
-- _NativeDouble. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:34:9)
+- Double. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:115:9)
+- _NativeDouble. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:35:9)
 - NativeType. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:12:9)
 - Object. (from org-dartlang-sdk:///sdk/lib/core/object.dart:25:9)
diff --git a/pkg/front_end/testcases/nnbd/ffi_sample.dart.weak.modular.expect b/pkg/front_end/testcases/nnbd/ffi_sample.dart.weak.modular.expect
index b190b3a9c292..b376ba2c5873 100644
--- a/pkg/front_end/testcases/nnbd/ffi_sample.dart.weak.modular.expect
+++ b/pkg/front_end/testcases/nnbd/ffi_sample.dart.weak.modular.expect
@@ -34,7 +34,7 @@ constants  {
 
 Constructor coverage from constants:
 org-dartlang-testcase:///ffi_sample.dart:
-- Double. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:114:9)
-- _NativeDouble. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:34:9)
+- Double. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:115:9)
+- _NativeDouble. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:35:9)
 - NativeType. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:12:9)
 - Object. (from org-dartlang-sdk:///sdk/lib/core/object.dart:25:9)
diff --git a/pkg/front_end/testcases/nnbd/ffi_sample.dart.weak.transformed.expect b/pkg/front_end/testcases/nnbd/ffi_sample.dart.weak.transformed.expect
index fccf63463e32..2b681fae1d35 100644
--- a/pkg/front_end/testcases/nnbd/ffi_sample.dart.weak.transformed.expect
+++ b/pkg/front_end/testcases/nnbd/ffi_sample.dart.weak.transformed.expect
@@ -65,7 +65,7 @@ constants  {
 
 Constructor coverage from constants:
 org-dartlang-testcase:///ffi_sample.dart:
-- Double. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:114:9)
-- _NativeDouble. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:34:9)
+- Double. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:115:9)
+- _NativeDouble. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:35:9)
 - NativeType. (from org-dartlang-sdk:///sdk/lib/ffi/native_type.dart:12:9)
 - Object. (from org-dartlang-sdk:///sdk/lib/core/object.dart:25:9)
diff --git a/runtime/tools/ffi/sdk_lib_ffi_generator.dart b/runtime/tools/ffi/sdk_lib_ffi_generator.dart
index d32b0a11427d..64b985a61344 100644
--- a/runtime/tools/ffi/sdk_lib_ffi_generator.dart
+++ b/runtime/tools/ffi/sdk_lib_ffi_generator.dart
@@ -24,12 +24,13 @@ const configuration = [
   Config("Uint16", "int", "Uint16List", 2),
   Config("Uint32", "int", "Uint32List", 4),
   Config("Uint64", "int", "Uint64List", 8),
-  Config("IntPtr", "int", kDoNotEmit, kIntPtrElementSize),
   Config("Float", "double", "Float32List", 4),
   Config("Double", "double", "Float64List", 8),
-  Config("Bool", "bool", kDoNotEmit, 1),
+  Config("Bool", "bool", kDoNotEmit, 1, since: Version(2, 15)),
 ];
 
+const arrayVersion = Version(2, 13);
+
 //
 // Generator.
 //
@@ -81,8 +82,6 @@ void generatePublicExtension(
   final elementSize = config.elementSize;
 
   final bits = sizeOfBits(elementSize);
-  // final sizeInBytes =
-  // "${sizeOf(elementSize)} byte${elementSize != 1 ? "s" : ""}";
 
   String property;
   if (_isInt(nativeType)) {
@@ -178,9 +177,10 @@ $alignment  external $typedListType asTypedList(int length);
 """;
 
   if (container == "Pointer") {
+    final since = config.since?.sinceAnnotation ?? '';
     buffer.write("""
 /// Extension on [Pointer] specialized for the type argument [$nativeType].
-extension ${nativeType}Pointer on Pointer<$nativeType> {
+$since extension ${nativeType}Pointer on Pointer<$nativeType> {
   /// The $property at [address].
 $platform$truncate$alignment  external $dartType get value;
 
@@ -197,9 +197,11 @@ $asTypedList
 
 """);
   } else {
+    final since =
+        Version.latest(config.since, arrayVersion)?.sinceAnnotation ?? '';
     buffer.write("""
 /// Bounds checking indexing methods on [Array]s of [$nativeType].
-extension ${nativeType}Array on Array<$nativeType> {
+$since extension ${nativeType}Array on Array<$nativeType> {
   external $dartType operator [](int index);
 
   external void operator []=(int index, $dartType value);
@@ -288,32 +290,11 @@ void generateFooter(StringBuffer buffer) {
 bool _isInt(String type) => type.startsWith("Int") || type.startsWith("Uint");
 bool _isSigned(String type) => type.startsWith("Int");
 
-String sizeOf(int size) {
-  switch (size) {
-    case kIntPtrElementSize:
-      return "4 or 8";
-    default:
-      return "$size";
-  }
-}
+String sizeOf(int size) => "$size";
 
-String sizeOfBits(int size) {
-  switch (size) {
-    case kIntPtrElementSize:
-      return "32 or 64";
-    default:
-      return "${size * 8}";
-  }
-}
+String sizeOfBits(int size) => "${size * 8}";
 
-String sizeOfIntPtrSize(int size) {
-  switch (size) {
-    case kIntPtrElementSize:
-      return "_intPtrSize";
-    default:
-      return "$size";
-  }
-}
+String sizeOfIntPtrSize(int size) => "$size";
 
 String bracketOr(String input) {
   if (input.contains("or")) {
@@ -348,9 +329,32 @@ class Config {
   final String dartType;
   final String typedListType;
   final int elementSize;
+  final Version? since;
   const Config(
-      this.nativeType, this.dartType, this.typedListType, this.elementSize);
+      this.nativeType, this.dartType, this.typedListType, this.elementSize,
+      {Version? since})
+      : since = since;
 }
 
 const String kDoNotEmit = "donotemit";
-const int kIntPtrElementSize = -1;
+
+class Version {
+  final int major;
+  final int minor;
+
+  const Version(this.major, this.minor);
+
+  @override
+  String toString() => '$major.$minor';
+
+  static Version? latest(Version? a, Version? b) {
+    if (a == null) return b;
+    if (b == null) return a;
+    if (a.major > b.major) return a;
+    if (b.major > a.major) return b;
+    if (a.minor > b.minor) return a;
+    return b;
+  }
+
+  String get sinceAnnotation => "@Since('$this')";
+}
diff --git a/sdk/lib/ffi/abi.dart b/sdk/lib/ffi/abi.dart
index 1efe4a55cf06..e6f08b37d25c 100644
--- a/sdk/lib/ffi/abi.dart
+++ b/sdk/lib/ffi/abi.dart
@@ -14,6 +14,7 @@ part of dart.ffi;
 /// The Dart VM can run on a variety of operating systems and architectures.
 /// Supported ABIs are represented by `Abi` objects.
 /// See [values] for all the supported ABIs.
+@Since('2.16')
 class Abi {
   /// The application binary interface for Android on the Arm architecture.
   static const androidArm = _androidArm;
diff --git a/sdk/lib/ffi/abi_specific.dart b/sdk/lib/ffi/abi_specific.dart
index a41308c44bec..61eb867be177 100644
--- a/sdk/lib/ffi/abi_specific.dart
+++ b/sdk/lib/ffi/abi_specific.dart
@@ -43,6 +43,7 @@ part of dart.ffi;
 ///   const UintPtr();
 /// }
 /// ```
+@Since('2.16')
 class AbiSpecificInteger extends NativeType {
   const AbiSpecificInteger();
 }
@@ -50,6 +51,7 @@ class AbiSpecificInteger extends NativeType {
 /// Mapping for a subtype of [AbiSpecificInteger].
 ///
 /// See documentation on [AbiSpecificInteger].
+@Since('2.16')
 class AbiSpecificIntegerMapping {
   final Map<Abi, NativeType> mapping;
 
diff --git a/sdk/lib/ffi/allocation.dart b/sdk/lib/ffi/allocation.dart
index fc5fce402787..45673ccc63ee 100644
--- a/sdk/lib/ffi/allocation.dart
+++ b/sdk/lib/ffi/allocation.dart
@@ -5,6 +5,7 @@
 part of dart.ffi;
 
 /// Manages memory on the native heap.
+@Since('2.12')
 abstract class Allocator {
   /// This interface is meant to be implemented, not extended or mixed in.
   Allocator._() {
@@ -28,6 +29,7 @@ abstract class Allocator {
 }
 
 /// Extension on [Allocator] to provide allocation with [NativeType].
+@Since('2.12')
 extension AllocatorAlloc on Allocator {
   /// Allocates `sizeOf<T>() * count` bytes of memory using
   /// `allocator.allocate`.
diff --git a/sdk/lib/ffi/c_type.dart b/sdk/lib/ffi/c_type.dart
index cb9d386342f8..ee358c2f79d1 100644
--- a/sdk/lib/ffi/c_type.dart
+++ b/sdk/lib/ffi/c_type.dart
@@ -21,6 +21,7 @@ part of dart.ffi;
 /// Dart code.
 /// It occurs only in native type signatures and as annotation on [Struct] and
 /// [Union] fields.
+@Since('2.17')
 @AbiSpecificIntegerMapping({
   Abi.androidArm: Uint8(),
   Abi.androidArm64: Uint8(),
@@ -57,6 +58,7 @@ class Char extends AbiSpecificInteger {
 /// Dart code.
 /// It occurs only in native type signatures and as annotation on [Struct] and
 /// [Union] fields.
+@Since('2.17')
 @AbiSpecificIntegerMapping({
   Abi.androidArm: Int8(),
   Abi.androidArm64: Int8(),
@@ -93,6 +95,7 @@ class SignedChar extends AbiSpecificInteger {
 /// Dart code.
 /// It occurs only in native type signatures and as annotation on [Struct] and
 /// [Union] fields.
+@Since('2.17')
 @AbiSpecificIntegerMapping({
   Abi.androidArm: Uint8(),
   Abi.androidArm64: Uint8(),
@@ -129,6 +132,7 @@ class UnsignedChar extends AbiSpecificInteger {
 /// Dart code.
 /// It occurs only in native type signatures and as annotation on [Struct] and
 /// [Union] fields.
+@Since('2.17')
 @AbiSpecificIntegerMapping({
   Abi.androidArm: Int16(),
   Abi.androidArm64: Int16(),
@@ -165,6 +169,7 @@ class Short extends AbiSpecificInteger {
 /// Dart code.
 /// It occurs only in native type signatures and as annotation on [Struct] and
 /// [Union] fields.
+@Since('2.17')
 @AbiSpecificIntegerMapping({
   Abi.androidArm: Uint16(),
   Abi.androidArm64: Uint16(),
@@ -201,6 +206,7 @@ class UnsignedShort extends AbiSpecificInteger {
 /// Dart code.
 /// It occurs only in native type signatures and as annotation on [Struct] and
 /// [Union] fields.
+@Since('2.17')
 @AbiSpecificIntegerMapping({
   Abi.androidArm: Int32(),
   Abi.androidArm64: Int32(),
@@ -237,6 +243,7 @@ class Int extends AbiSpecificInteger {
 /// Dart code.
 /// It occurs only in native type signatures and as annotation on [Struct] and
 /// [Union] fields.
+@Since('2.17')
 @AbiSpecificIntegerMapping({
   Abi.androidArm: Uint32(),
   Abi.androidArm64: Uint32(),
@@ -274,6 +281,7 @@ class UnsignedInt extends AbiSpecificInteger {
 /// Dart code.
 /// It occurs only in native type signatures and as annotation on [Struct] and
 /// [Union] fields.
+@Since('2.17')
 @AbiSpecificIntegerMapping({
   Abi.androidArm: Int32(),
   Abi.androidArm64: Int64(),
@@ -311,6 +319,7 @@ class Long extends AbiSpecificInteger {
 /// Dart code.
 /// It occurs only in native type signatures and as annotation on [Struct] and
 /// [Union] fields.
+@Since('2.17')
 @AbiSpecificIntegerMapping({
   Abi.androidArm: Uint32(),
   Abi.androidArm64: Uint64(),
@@ -347,6 +356,7 @@ class UnsignedLong extends AbiSpecificInteger {
 /// Dart code.
 /// It occurs only in native type signatures and as annotation on [Struct] and
 /// [Union] fields.
+@Since('2.17')
 @AbiSpecificIntegerMapping({
   Abi.androidArm: Int64(),
   Abi.androidArm64: Int64(),
@@ -383,6 +393,7 @@ class LongLong extends AbiSpecificInteger {
 /// in Dart code.
 /// It occurs only in native type signatures and as annotation on [Struct] and
 /// [Union] fields.
+@Since('2.17')
 @AbiSpecificIntegerMapping({
   Abi.androidArm: Uint64(),
   Abi.androidArm64: Uint64(),
@@ -447,6 +458,7 @@ class IntPtr extends AbiSpecificInteger {
 /// Dart code.
 /// It occurs only in native type signatures and as annotation on [Struct] and
 /// [Union] fields.
+@Since('2.17')
 @AbiSpecificIntegerMapping({
   Abi.androidArm: Uint32(),
   Abi.androidArm64: Uint64(),
@@ -479,6 +491,7 @@ class UintPtr extends AbiSpecificInteger {
 /// Dart code.
 /// It occurs only in native type signatures and as annotation on [Struct] and
 /// [Union] fields.
+@Since('2.17')
 @AbiSpecificIntegerMapping({
   Abi.androidArm: Uint32(),
   Abi.androidArm64: Uint64(),
@@ -514,6 +527,7 @@ class Size extends AbiSpecificInteger {
 /// Dart code.
 /// It occurs only in native type signatures and as annotation on [Struct] and
 /// [Union] fields.
+@Since('2.17')
 @AbiSpecificIntegerMapping({
   Abi.androidArm: Uint32(),
   Abi.androidArm64: Uint32(),
diff --git a/sdk/lib/ffi/ffi.dart b/sdk/lib/ffi/ffi.dart
index 0d4d5b71619e..8311238b93a0 100644
--- a/sdk/lib/ffi/ffi.dart
+++ b/sdk/lib/ffi/ffi.dart
@@ -2,13 +2,12 @@
 // 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
 
-/**
- * Foreign Function Interface for interoperability with the C programming language.
- *
- * For further details, please see: https://dart.dev/server/c-interop
- *
- * {@category VM}
- */
+/// Foreign Function Interface for interoperability with the C programming language.
+///
+/// For further details, please see: https://dart.dev/server/c-interop.
+///
+/// {@category VM}
+@Since('2.6')
 library dart.ffi;
 
 import 'dart:_internal' show Since;
@@ -93,6 +92,7 @@ class Pointer<T extends NativeType> extends NativeType {
 }
 
 /// A fixed-sized array of [T]s.
+@Since('2.13')
 class Array<T extends NativeType> extends NativeType {
   /// Const constructor to specify [Array] dimensions in [Struct]s.
   ///
@@ -523,6 +523,7 @@ extension DoublePointer on Pointer<Double> {
 }
 
 /// Extension on [Pointer] specialized for the type argument [Bool].
+@Since('2.15')
 extension BoolPointer on Pointer<Bool> {
   /// The bool at [address].
   external bool get value;
@@ -537,6 +538,7 @@ extension BoolPointer on Pointer<Bool> {
 }
 
 /// Bounds checking indexing methods on [Array]s of [Int8].
+@Since('2.13')
 extension Int8Array on Array<Int8> {
   external int operator [](int index);
 
@@ -544,6 +546,7 @@ extension Int8Array on Array<Int8> {
 }
 
 /// Bounds checking indexing methods on [Array]s of [Int16].
+@Since('2.13')
 extension Int16Array on Array<Int16> {
   external int operator [](int index);
 
@@ -551,6 +554,7 @@ extension Int16Array on Array<Int16> {
 }
 
 /// Bounds checking indexing methods on [Array]s of [Int32].
+@Since('2.13')
 extension Int32Array on Array<Int32> {
   external int operator [](int index);
 
@@ -558,6 +562,7 @@ extension Int32Array on Array<Int32> {
 }
 
 /// Bounds checking indexing methods on [Array]s of [Int64].
+@Since('2.13')
 extension Int64Array on Array<Int64> {
   external int operator [](int index);
 
@@ -565,6 +570,7 @@ extension Int64Array on Array<Int64> {
 }
 
 /// Bounds checking indexing methods on [Array]s of [Uint8].
+@Since('2.13')
 extension Uint8Array on Array<Uint8> {
   external int operator [](int index);
 
@@ -572,6 +578,7 @@ extension Uint8Array on Array<Uint8> {
 }
 
 /// Bounds checking indexing methods on [Array]s of [Uint16].
+@Since('2.13')
 extension Uint16Array on Array<Uint16> {
   external int operator [](int index);
 
@@ -579,6 +586,7 @@ extension Uint16Array on Array<Uint16> {
 }
 
 /// Bounds checking indexing methods on [Array]s of [Uint32].
+@Since('2.13')
 extension Uint32Array on Array<Uint32> {
   external int operator [](int index);
 
@@ -586,6 +594,7 @@ extension Uint32Array on Array<Uint32> {
 }
 
 /// Bounds checking indexing methods on [Array]s of [Uint64].
+@Since('2.13')
 extension Uint64Array on Array<Uint64> {
   external int operator [](int index);
 
@@ -593,6 +602,7 @@ extension Uint64Array on Array<Uint64> {
 }
 
 /// Bounds checking indexing methods on [Array]s of [Float].
+@Since('2.13')
 extension FloatArray on Array<Float> {
   external double operator [](int index);
 
@@ -600,6 +610,7 @@ extension FloatArray on Array<Float> {
 }
 
 /// Bounds checking indexing methods on [Array]s of [Double].
+@Since('2.13')
 extension DoubleArray on Array<Double> {
   external double operator [](int index);
 
@@ -607,6 +618,7 @@ extension DoubleArray on Array<Double> {
 }
 
 /// Bounds checking indexing methods on [Array]s of [Bool].
+@Since('2.15')
 extension BoolArray on Array<Bool> {
   external bool operator [](int index);
 
@@ -642,7 +654,7 @@ extension PointerPointer<T extends NativeType> on Pointer<Pointer<T>> {
   /// Store a Dart value into this location offset by [index].
   ///
   /// A [Pointer] is unboxed before being stored (as if by `.address`), and the
-  /// pointer is boxed (as if by `Pointer.fromAddress`) when loaded.
+  /// pointer is boxed (as if by [Pointer.fromAddress]) when loaded.
   ///
   /// On 32-bit platforms the [address] must be 4-byte aligned, and on 64-bit
   /// platforms the [address] must be 8-byte aligned.
@@ -650,6 +662,7 @@ extension PointerPointer<T extends NativeType> on Pointer<Pointer<T>> {
 }
 
 /// Extension on [Pointer] specialized for the type argument [Struct].
+@Since('2.12')
 extension StructPointer<T extends Struct> on Pointer<T> {
   /// A Dart view of the struct referenced by this pointer.
   ///
@@ -685,6 +698,7 @@ extension StructPointer<T extends Struct> on Pointer<T> {
 }
 
 /// Extension on [Pointer] specialized for the type argument [Union].
+@Since('2.14')
 extension UnionPointer<T extends Union> on Pointer<T> {
   /// A Dart view of the union referenced by this pointer.
   ///
@@ -721,6 +735,7 @@ extension UnionPointer<T extends Union> on Pointer<T> {
 
 /// Extension on [Pointer] specialized for the type argument
 /// [AbiSpecificInteger].
+@Since('2.16')
 extension AbiSpecificIntegerPointer<T extends AbiSpecificInteger>
     on Pointer<T> {
   /// The integer at [address].
@@ -736,6 +751,7 @@ extension AbiSpecificIntegerPointer<T extends AbiSpecificInteger>
 }
 
 /// Bounds checking indexing methods on [Array]s of [Pointer].
+@Since('2.13')
 extension PointerArray<T extends NativeType> on Array<Pointer<T>> {
   external Pointer<T> operator [](int index);
 
@@ -743,6 +759,7 @@ extension PointerArray<T extends NativeType> on Array<Pointer<T>> {
 }
 
 /// Bounds checking indexing methods on [Array]s of [Struct].
+@Since('2.13')
 extension StructArray<T extends Struct> on Array<T> {
   /// This extension method must be invoked on a receiver of type `Pointer<T>`
   /// where `T` is a compile-time constant type.
@@ -750,6 +767,7 @@ extension StructArray<T extends Struct> on Array<T> {
 }
 
 /// Bounds checking indexing methods on [Array]s of [Union].
+@Since('2.14')
 extension UnionArray<T extends Union> on Array<T> {
   /// This extension method must be invoked on a receiver of type `Pointer<T>`
   /// where `T` is a compile-time constant type.
@@ -757,6 +775,7 @@ extension UnionArray<T extends Union> on Array<T> {
 }
 
 /// Bounds checking indexing methods on [Array]s of [Array].
+@Since('2.13')
 extension ArrayArray<T extends NativeType> on Array<Array<T>> {
   external Array<T> operator [](int index);
 
@@ -764,6 +783,7 @@ extension ArrayArray<T extends NativeType> on Array<Array<T>> {
 }
 
 /// Bounds checking indexing methods on [Array]s of [AbiSpecificInteger].
+@Since('2.16')
 extension AbiSpecificIntegerArray on Array<AbiSpecificInteger> {
   external int operator [](int index);
 
@@ -771,31 +791,40 @@ extension AbiSpecificIntegerArray on Array<AbiSpecificInteger> {
 }
 
 /// Extension to retrieve the native `Dart_Port` from a [SendPort].
+@Since('2.7')
 extension NativePort on SendPort {
   /// The native port of this [SendPort].
   ///
   /// The returned native port can for example be used by C code to post
   /// messages to the connected [ReceivePort] via `Dart_PostCObject()` - see
   /// `dart_native_api.h`.
+  ///
+  /// Only the send ports from the platform classes [ReceivePort] and
+  /// [RawReceivePort] are supported. User-defined implementations of
+  /// [SendPort] are not supported.
   external int get nativePort;
 }
 
 /// Opaque, not exposing it's members.
+@Since('2.8')
 class Dart_CObject extends Opaque {}
 
 typedef Dart_NativeMessageHandler = Void Function(Int64, Pointer<Dart_CObject>);
 
 /// Utilities for accessing the Dart VM API from Dart code or
 /// from C code via `dart_api_dl.h`.
+@Since('2.8')
 abstract class NativeApi {
   /// On breaking changes the major version is increased.
   ///
   /// The versioning covers the API surface in `dart_api_dl.h`.
+  @Since('2.9')
   external static int get majorVersion;
 
   /// On backwards compatible changes the minor version is increased.
   ///
   /// The versioning covers the API surface in `dart_api_dl.h`.
+  @Since('2.9')
   external static int get minorVersion;
 
   /// A function pointer to
@@ -827,6 +856,7 @@ abstract class NativeApi {
 
   /// Pass this to `Dart_InitializeApiDL` in your native code to enable using the
   /// symbols in `dart_api_dl.h`.
+  @Since('2.9')
   external static Pointer<Void> get initializeApiDLData;
 }
 
@@ -843,6 +873,7 @@ abstract class NativeApi {
 /// See `Dart_SetFfiNativeResolver` in `dart_api.h`
 ///
 /// NOTE: This is an experimental feature and may change in the future.
+@Since('2.14')
 class FfiNative<T> {
   final String nativeName;
   final bool isLeaf;
diff --git a/sdk/lib/ffi/native_finalizer.dart b/sdk/lib/ffi/native_finalizer.dart
index 14074cf6cae5..fcc44377a660 100644
--- a/sdk/lib/ffi/native_finalizer.dart
+++ b/sdk/lib/ffi/native_finalizer.dart
@@ -218,6 +218,7 @@ part of dart.ffi;
 /// ```
 // TODO(http://dartbug.com/44395): Add implicit await to Dart implementation.
 // This will fix `useAsync2` above.
+@Since('2.17')
 abstract class Finalizable {
   factory Finalizable._() => throw UnsupportedError("");
 }
@@ -246,6 +247,7 @@ typedef NativeFinalizerFunction
 /// attached finalizers are definitely called at least once before the program
 /// ends, and the callbacks are called as soon as possible after an object
 /// is recognized as inaccessible.
+@Since('2.17')
 abstract class NativeFinalizer {
   /// Creates a finalizer with the given finalization callback.
   ///
diff --git a/sdk/lib/ffi/native_type.dart b/sdk/lib/ffi/native_type.dart
index 55a9f6d52463..62db0d59a41d 100644
--- a/sdk/lib/ffi/native_type.dart
+++ b/sdk/lib/ffi/native_type.dart
@@ -16,6 +16,7 @@ abstract class NativeType {
 ///
 /// [Opaque]'s subtypes are not constructible in the Dart code and serve purely
 /// as markers in type signatures.
+@Since('2.12')
 abstract class Opaque extends NativeType {}
 
 /// [_NativeInteger]'s subtypes represent a native integer in C.
@@ -118,6 +119,7 @@ class Double extends _NativeDouble {
 ///
 /// [Bool] is not constructible in the Dart code and serves purely as marker
 /// in type signatures.
+@Since('2.15')
 class Bool extends NativeType {
   const Bool();
 }
@@ -133,6 +135,7 @@ abstract class Void extends NativeType {}
 ///
 /// [Handle] is not constructible in the Dart code and serves purely as marker in
 /// type signatures.
+@Since('2.9')
 abstract class Handle extends NativeType {}
 
 /// Represents a function type in C.
diff --git a/sdk/lib/ffi/struct.dart b/sdk/lib/ffi/struct.dart
index c02a0599be34..3f84c42e3826 100644
--- a/sdk/lib/ffi/struct.dart
+++ b/sdk/lib/ffi/struct.dart
@@ -61,6 +61,7 @@ abstract class _Compound extends NativeType {
 /// by native memory or typed data. They may allocated via allocation or loaded
 /// from a [Pointer] or created by ffi calls or callbacks. They cannot be
 /// created by a generative constructor.
+@Since('2.12')
 abstract class Struct extends _Compound {
   /// Construct a reference to the [nullptr].
   ///
@@ -76,6 +77,7 @@ abstract class Struct extends _Compound {
 /// need to be packed.
 ///
 /// Valid values for [memberAlignment] are 1, 2, 4, 8, and 16.
+@Since('2.13')
 class Packed {
   final int memberAlignment;
 
diff --git a/sdk/lib/ffi/union.dart b/sdk/lib/ffi/union.dart
index 60242fed984b..8d2ee9ebd977 100644
--- a/sdk/lib/ffi/union.dart
+++ b/sdk/lib/ffi/union.dart
@@ -46,6 +46,7 @@ part of dart.ffi;
 /// Instances of a subclass of [Union] have reference semantics and are backed
 /// by native memory. The may allocated via allocation or loaded from a
 /// [Pointer], but cannot be created by a generative constructor.
+@Since('2.14')
 abstract class Union extends _Compound {
   /// Construct a reference to the [nullptr].
   ///