diff --git a/sdk/sdk.go b/sdk/sdk.go
new file mode 100644
index 0000000..fcb3fb7
--- /dev/null
+++ b/sdk/sdk.go
@@ -0,0 +1,172 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package sdk
+
+import (
+	"github.com/google/blueprint"
+
+	"android/soong/android"
+	// This package doesn't depend on the apex package, but import it to make its mutators to be
+	// registered before mutators in this package. See RegisterPostDepsMutators for more details.
+	_ "android/soong/apex"
+)
+
+func init() {
+	android.RegisterModuleType("sdk", ModuleFactory)
+	android.PreDepsMutators(RegisterPreDepsMutators)
+	android.PostDepsMutators(RegisterPostDepsMutators)
+}
+
+type sdk struct {
+	android.ModuleBase
+	android.DefaultableModuleBase
+
+	properties sdkProperties
+}
+
+type sdkProperties struct {
+	// The list of java_import modules that provide Java stubs for this SDK
+	Java_libs          []string
+	Native_shared_libs []string
+}
+
+// sdk defines an SDK which is a logical group of modules (e.g. native libs, headers, java libs, etc.)
+// which Mainline modules like APEX can choose to build with.
+func ModuleFactory() android.Module {
+	s := &sdk{}
+	s.AddProperties(&s.properties)
+	android.InitAndroidMultiTargetsArchModule(s, android.HostAndDeviceSupported, android.MultilibCommon)
+	android.InitDefaultableModule(s)
+	return s
+}
+
+func (s *sdk) GenerateAndroidBuildActions(ctx android.ModuleContext) {
+	// TODO(jiyong): add build rules for creating stubs from members of this SDK
+}
+
+// RegisterPreDepsMutators registers pre-deps mutators to support modules implementing SdkAware
+// interface and the sdk module type. This function has been made public to be called by tests
+// outside of the sdk package
+func RegisterPreDepsMutators(ctx android.RegisterMutatorsContext) {
+	ctx.BottomUp("SdkMember", memberMutator).Parallel()
+	ctx.TopDown("SdkMember_deps", memberDepsMutator).Parallel()
+	ctx.BottomUp("SdkMemberInterVersion", memberInterVersionMutator).Parallel()
+}
+
+// RegisterPostDepshMutators registers post-deps mutators to support modules implementing SdkAware
+// interface and the sdk module type. This function has been made public to be called by tests
+// outside of the sdk package
+func RegisterPostDepsMutators(ctx android.RegisterMutatorsContext) {
+	// These must run AFTER apexMutator. Note that the apex package is imported even though there is
+	// no direct dependency to the package here. sdkDepsMutator sets the SDK requirements from an
+	// APEX to its dependents. Since different versions of the same SDK can be used by different
+	// APEXes, the apex and its dependents (which includes the dependencies to the sdk members)
+	// should have been mutated for the apex before the SDK requirements are set.
+	ctx.TopDown("SdkDepsMutator", sdkDepsMutator).Parallel()
+	ctx.BottomUp("SdkDepsReplaceMutator", sdkDepsReplaceMutator).Parallel()
+}
+
+type dependencyTag struct {
+	blueprint.BaseDependencyTag
+}
+
+// For dependencies from an SDK module to its members
+// e.g. mysdk -> libfoo and libbar
+var sdkMemberDepTag dependencyTag
+
+// For dependencies from an in-development version of an SDK member to frozen versions of the same member
+// e.g. libfoo -> libfoo.mysdk.11 and libfoo.mysdk.12
+type sdkMemberVesionedDepTag struct {
+	dependencyTag
+	member  string
+	version string
+}
+
+// Step 1: create dependencies from an SDK module to its members.
+func memberMutator(mctx android.BottomUpMutatorContext) {
+	if m, ok := mctx.Module().(*sdk); ok {
+		mctx.AddVariationDependencies(nil, sdkMemberDepTag, m.properties.Java_libs...)
+
+		targets := mctx.MultiTargets()
+		for _, target := range targets {
+			mctx.AddFarVariationDependencies([]blueprint.Variation{
+				{Mutator: "arch", Variation: target.String()},
+				{Mutator: "image", Variation: "core"},
+				{Mutator: "link", Variation: "shared"},
+			}, sdkMemberDepTag, m.properties.Native_shared_libs...)
+		}
+	}
+}
+
+// Step 2: record that dependencies of SDK modules are members of the SDK modules
+func memberDepsMutator(mctx android.TopDownMutatorContext) {
+	if _, ok := mctx.Module().(*sdk); ok {
+		mySdkRef := android.ParseSdkRef(mctx, mctx.ModuleName(), "name")
+		mctx.VisitDirectDeps(func(child android.Module) {
+			if member, ok := child.(android.SdkAware); ok {
+				member.MakeMemberOf(mySdkRef)
+			}
+		})
+	}
+}
+
+// Step 3: create dependencies from the in-development version of an SDK member to frozen versions
+// of the same member. By having these dependencies, they are mutated for multiple Mainline modules
+// (apex and apk), each of which might want different sdks to be built with. For example, if both
+// apex A and B are referencing libfoo which is a member of sdk 'mysdk', the two APEXes can be
+// built with libfoo.mysdk.11 and libfoo.mysdk.12, respectively depending on which sdk they are
+// using.
+func memberInterVersionMutator(mctx android.BottomUpMutatorContext) {
+	if m, ok := mctx.Module().(android.SdkAware); ok && m.IsInAnySdk() {
+		if !m.ContainingSdk().IsCurrentVersion() {
+			memberName := m.MemberName()
+			tag := sdkMemberVesionedDepTag{member: memberName, version: m.ContainingSdk().Version}
+			mctx.AddReverseDependency(mctx.Module(), tag, memberName)
+		}
+	}
+}
+
+// Step 4: transitively ripple down the SDK requirements from the root modules like APEX to its
+// descendants
+func sdkDepsMutator(mctx android.TopDownMutatorContext) {
+	if m, ok := mctx.Module().(android.SdkAware); ok {
+		// Module types for Mainline modules (e.g. APEX) are expected to implement RequiredSdks()
+		// by reading its own properties like `uses_sdks`.
+		requiredSdks := m.RequiredSdks()
+		if len(requiredSdks) > 0 {
+			mctx.VisitDirectDeps(func(m android.Module) {
+				if dep, ok := m.(android.SdkAware); ok {
+					dep.BuildWithSdks(requiredSdks)
+				}
+			})
+		}
+	}
+}
+
+// Step 5: if libfoo.mysdk.11 is in the context where version 11 of mysdk is requested, the
+// versioned module is used instead of the un-versioned (in-development) module libfoo
+func sdkDepsReplaceMutator(mctx android.BottomUpMutatorContext) {
+	if m, ok := mctx.Module().(android.SdkAware); ok && m.IsInAnySdk() {
+		if sdk := m.ContainingSdk(); !sdk.IsCurrentVersion() {
+			if m.RequiredSdks().Contains(sdk) {
+				// Note that this replacement is done only for the modules that have the same
+				// variations as the current module. Since current module is already mutated for
+				// apex references in other APEXes are not affected by this replacement.
+				memberName := m.MemberName()
+				mctx.ReplaceDependencies(memberName)
+			}
+		}
+	}
+}
diff --git a/sdk/sdk_test.go b/sdk/sdk_test.go
new file mode 100644
index 0000000..9eca72f
--- /dev/null
+++ b/sdk/sdk_test.go
@@ -0,0 +1,318 @@
+// Copyright 2019 Google Inc. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package sdk
+
+import (
+	"io/ioutil"
+	"os"
+	"strings"
+	"testing"
+
+	"android/soong/android"
+	"android/soong/apex"
+	"android/soong/cc"
+	"android/soong/java"
+)
+
+func testSdkContext(t *testing.T, bp string) (*android.TestContext, android.Config) {
+	config := android.TestArchConfig(buildDir, nil)
+	ctx := android.NewTestArchContext()
+
+	// from android package
+	ctx.PreArchMutators(android.RegisterDefaultsPreArchMutators)
+	ctx.PreArchMutators(func(ctx android.RegisterMutatorsContext) {
+		ctx.BottomUp("prebuilts", android.PrebuiltMutator).Parallel()
+	})
+	ctx.PostDepsMutators(func(ctx android.RegisterMutatorsContext) {
+		ctx.TopDown("prebuilt_select", android.PrebuiltSelectModuleMutator).Parallel()
+		ctx.BottomUp("prebuilt_postdeps", android.PrebuiltPostDepsMutator).Parallel()
+	})
+
+	// from java package
+	ctx.RegisterModuleType("android_app_certificate", android.ModuleFactoryAdaptor(java.AndroidAppCertificateFactory))
+	ctx.RegisterModuleType("java_library", android.ModuleFactoryAdaptor(java.LibraryFactory))
+	ctx.RegisterModuleType("java_import", android.ModuleFactoryAdaptor(java.ImportFactory))
+
+	// from cc package
+	ctx.RegisterModuleType("cc_library", android.ModuleFactoryAdaptor(cc.LibraryFactory))
+	ctx.RegisterModuleType("cc_library_shared", android.ModuleFactoryAdaptor(cc.LibrarySharedFactory))
+	ctx.RegisterModuleType("cc_object", android.ModuleFactoryAdaptor(cc.ObjectFactory))
+	ctx.RegisterModuleType("cc_prebuilt_library_shared", android.ModuleFactoryAdaptor(cc.PrebuiltSharedLibraryFactory))
+	ctx.RegisterModuleType("cc_prebuilt_library_static", android.ModuleFactoryAdaptor(cc.PrebuiltStaticLibraryFactory))
+	ctx.RegisterModuleType("llndk_library", android.ModuleFactoryAdaptor(cc.LlndkLibraryFactory))
+	ctx.RegisterModuleType("toolchain_library", android.ModuleFactoryAdaptor(cc.ToolchainLibraryFactory))
+	ctx.PreDepsMutators(func(ctx android.RegisterMutatorsContext) {
+		ctx.BottomUp("image", cc.ImageMutator).Parallel()
+		ctx.BottomUp("link", cc.LinkageMutator).Parallel()
+		ctx.BottomUp("vndk", cc.VndkMutator).Parallel()
+		ctx.BottomUp("test_per_src", cc.TestPerSrcMutator).Parallel()
+		ctx.BottomUp("version", cc.VersionMutator).Parallel()
+		ctx.BottomUp("begin", cc.BeginMutator).Parallel()
+	})
+
+	// from apex package
+	ctx.RegisterModuleType("apex", android.ModuleFactoryAdaptor(apex.BundleFactory))
+	ctx.RegisterModuleType("apex_key", android.ModuleFactoryAdaptor(apex.ApexKeyFactory))
+	ctx.PostDepsMutators(apex.RegisterPostDepsMutators)
+
+	// from this package
+	ctx.RegisterModuleType("sdk", android.ModuleFactoryAdaptor(ModuleFactory))
+	ctx.PreDepsMutators(RegisterPreDepsMutators)
+	ctx.PostDepsMutators(RegisterPostDepsMutators)
+
+	ctx.Register()
+
+	bp = bp + `
+		apex_key {
+			name: "myapex.key",
+			public_key: "myapex.avbpubkey",
+			private_key: "myapex.pem",
+		}
+
+		android_app_certificate {
+			name: "myapex.cert",
+			certificate: "myapex",
+		}
+	` + cc.GatherRequiredDepsForTest(android.Android)
+
+	ctx.MockFileSystem(map[string][]byte{
+		"Android.bp":                                 []byte(bp),
+		"build/make/target/product/security":         nil,
+		"apex_manifest.json":                         nil,
+		"system/sepolicy/apex/myapex-file_contexts":  nil,
+		"system/sepolicy/apex/myapex2-file_contexts": nil,
+		"myapex.avbpubkey":                           nil,
+		"myapex.pem":                                 nil,
+		"myapex.x509.pem":                            nil,
+		"myapex.pk8":                                 nil,
+		"Test.java":                                  nil,
+		"Test.cpp":                                   nil,
+		"libfoo.so":                                  nil,
+	})
+
+	return ctx, config
+}
+
+func testSdk(t *testing.T, bp string) (*android.TestContext, android.Config) {
+	ctx, config := testSdkContext(t, bp)
+	_, errs := ctx.ParseFileList(".", []string{"Android.bp"})
+	android.FailIfErrored(t, errs)
+	_, errs = ctx.PrepareBuildActions(config)
+	android.FailIfErrored(t, errs)
+	return ctx, config
+}
+
+// ensure that 'result' contains 'expected'
+func ensureContains(t *testing.T, result string, expected string) {
+	t.Helper()
+	if !strings.Contains(result, expected) {
+		t.Errorf("%q is not found in %q", expected, result)
+	}
+}
+
+// ensures that 'result' does not contain 'notExpected'
+func ensureNotContains(t *testing.T, result string, notExpected string) {
+	t.Helper()
+	if strings.Contains(result, notExpected) {
+		t.Errorf("%q is found in %q", notExpected, result)
+	}
+}
+
+func ensureListContains(t *testing.T, result []string, expected string) {
+	t.Helper()
+	if !android.InList(expected, result) {
+		t.Errorf("%q is not found in %v", expected, result)
+	}
+}
+
+func ensureListNotContains(t *testing.T, result []string, notExpected string) {
+	t.Helper()
+	if android.InList(notExpected, result) {
+		t.Errorf("%q is found in %v", notExpected, result)
+	}
+}
+
+func pathsToStrings(paths android.Paths) []string {
+	ret := []string{}
+	for _, p := range paths {
+		ret = append(ret, p.String())
+	}
+	return ret
+}
+
+func TestBasicSdkWithJava(t *testing.T) {
+	ctx, _ := testSdk(t, `
+		sdk {
+			name: "mysdk#1",
+			java_libs: ["sdkmember_mysdk_1"],
+		}
+
+		sdk {
+			name: "mysdk#2",
+			java_libs: ["sdkmember_mysdk_2"],
+		}
+
+		java_import {
+			name: "sdkmember",
+			prefer: false,
+			host_supported: true,
+		}
+
+		java_import {
+			name: "sdkmember_mysdk_1",
+			sdk_member_name: "sdkmember",
+			host_supported: true,
+		}
+
+		java_import {
+			name: "sdkmember_mysdk_2",
+			sdk_member_name: "sdkmember",
+			host_supported: true,
+		}
+
+		java_library {
+			name: "myjavalib",
+			srcs: ["Test.java"],
+			libs: ["sdkmember"],
+			system_modules: "none",
+			sdk_version: "none",
+			compile_dex: true,
+			host_supported: true,
+		}
+
+		apex {
+			name: "myapex",
+			java_libs: ["myjavalib"],
+			uses_sdks: ["mysdk#1"],
+			key: "myapex.key",
+			certificate: ":myapex.cert",
+		}
+
+		apex {
+			name: "myapex2",
+			java_libs: ["myjavalib"],
+			uses_sdks: ["mysdk#2"],
+			key: "myapex.key",
+			certificate: ":myapex.cert",
+		}
+	`)
+
+	sdkMemberV1 := ctx.ModuleForTests("sdkmember_mysdk_1", "android_common_myapex").Rule("combineJar").Output
+	sdkMemberV2 := ctx.ModuleForTests("sdkmember_mysdk_2", "android_common_myapex2").Rule("combineJar").Output
+
+	javalibForMyApex := ctx.ModuleForTests("myjavalib", "android_common_myapex")
+	javalibForMyApex2 := ctx.ModuleForTests("myjavalib", "android_common_myapex2")
+
+	// Depending on the uses_sdks value, different libs are linked
+	ensureListContains(t, pathsToStrings(javalibForMyApex.Rule("javac").Implicits), sdkMemberV1.String())
+	ensureListContains(t, pathsToStrings(javalibForMyApex2.Rule("javac").Implicits), sdkMemberV2.String())
+}
+
+func TestBasicSdkWithCc(t *testing.T) {
+	ctx, _ := testSdk(t, `
+		sdk {
+			name: "mysdk#1",
+			native_shared_libs: ["sdkmember_mysdk_1"],
+		}
+
+		sdk {
+			name: "mysdk#2",
+			native_shared_libs: ["sdkmember_mysdk_2"],
+		}
+
+		cc_prebuilt_library_shared {
+			name: "sdkmember",
+			srcs: ["libfoo.so"],
+			prefer: false,
+			system_shared_libs: [],
+			stl: "none",
+		}
+
+		cc_prebuilt_library_shared {
+			name: "sdkmember_mysdk_1",
+			sdk_member_name: "sdkmember",
+			srcs: ["libfoo.so"],
+			system_shared_libs: [],
+			stl: "none",
+		}
+
+		cc_prebuilt_library_shared {
+			name: "sdkmember_mysdk_2",
+			sdk_member_name: "sdkmember",
+			srcs: ["libfoo.so"],
+			system_shared_libs: [],
+			stl: "none",
+		}
+
+		cc_library_shared {
+			name: "mycpplib",
+			srcs: ["Test.cpp"],
+			shared_libs: ["sdkmember"],
+			system_shared_libs: [],
+			stl: "none",
+		}
+
+		apex {
+			name: "myapex",
+			native_shared_libs: ["mycpplib"],
+			uses_sdks: ["mysdk#1"],
+			key: "myapex.key",
+			certificate: ":myapex.cert",
+		}
+
+		apex {
+			name: "myapex2",
+			native_shared_libs: ["mycpplib"],
+			uses_sdks: ["mysdk#2"],
+			key: "myapex.key",
+			certificate: ":myapex.cert",
+		}
+	`)
+
+	sdkMemberV1 := ctx.ModuleForTests("sdkmember_mysdk_1", "android_arm64_armv8-a_core_shared_myapex").Rule("toc").Output
+	sdkMemberV2 := ctx.ModuleForTests("sdkmember_mysdk_2", "android_arm64_armv8-a_core_shared_myapex2").Rule("toc").Output
+
+	cpplibForMyApex := ctx.ModuleForTests("mycpplib", "android_arm64_armv8-a_core_shared_myapex")
+	cpplibForMyApex2 := ctx.ModuleForTests("mycpplib", "android_arm64_armv8-a_core_shared_myapex2")
+
+	// Depending on the uses_sdks value, different libs are linked
+	ensureListContains(t, pathsToStrings(cpplibForMyApex.Rule("ld").Implicits), sdkMemberV1.String())
+	ensureListContains(t, pathsToStrings(cpplibForMyApex2.Rule("ld").Implicits), sdkMemberV2.String())
+}
+
+var buildDir string
+
+func setUp() {
+	var err error
+	buildDir, err = ioutil.TempDir("", "soong_sdk_test")
+	if err != nil {
+		panic(err)
+	}
+}
+
+func tearDown() {
+	os.RemoveAll(buildDir)
+}
+
+func TestMain(m *testing.M) {
+	run := func() int {
+		setUp()
+		defer tearDown()
+
+		return m.Run()
+	}
+
+	os.Exit(run())
+}