diff --git a/android/Android.bp b/android/Android.bp
index 773aa6a..a32e8f2 100644
--- a/android/Android.bp
+++ b/android/Android.bp
@@ -67,6 +67,7 @@
         "rule_builder.go",
         "sandbox.go",
         "sdk.go",
+        "sdk_version.go",
         "singleton.go",
         "singleton_module.go",
         "soong_config_modules.go",
diff --git a/android/api_levels.go b/android/api_levels.go
index 2f6a9d2..9bc7e83 100644
--- a/android/api_levels.go
+++ b/android/api_levels.go
@@ -31,9 +31,9 @@
 // ApiLevelFromUser or ApiLevelOrPanic.
 //
 // The different *types* of API levels are handled separately. Currently only
-// Java has these, and they're managed with the sdkKind enum of the sdkSpec. A
-// future cleanup should be to migrate sdkSpec to using ApiLevel instead of its
-// sdkVersion int, and to move sdkSpec into this package.
+// Java has these, and they're managed with the SdkKind enum of the SdkSpec. A
+// future cleanup should be to migrate SdkSpec to using ApiLevel instead of its
+// SdkVersion int, and to move SdkSpec into this package.
 type ApiLevel struct {
 	// The string representation of the API level.
 	value string
diff --git a/android/sdk_version.go b/android/sdk_version.go
new file mode 100644
index 0000000..ce22b5f
--- /dev/null
+++ b/android/sdk_version.go
@@ -0,0 +1,311 @@
+// Copyright 2021 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 android
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+)
+
+type SdkContext interface {
+	// SdkVersion returns SdkSpec that corresponds to the sdk_version property of the current module
+	SdkVersion() SdkSpec
+	// SystemModules returns the system_modules property of the current module, or an empty string if it is not set.
+	SystemModules() string
+	// MinSdkVersion returns SdkSpec that corresponds to the min_sdk_version property of the current module,
+	// or from sdk_version if it is not set.
+	MinSdkVersion() SdkSpec
+	// TargetSdkVersion returns the SdkSpec that corresponds to the target_sdk_version property of the current module,
+	// or from sdk_version if it is not set.
+	TargetSdkVersion() SdkSpec
+}
+
+// SdkKind represents a particular category of an SDK spec like public, system, test, etc.
+type SdkKind int
+
+const (
+	SdkInvalid SdkKind = iota
+	SdkNone
+	SdkCore
+	SdkCorePlatform
+	SdkPublic
+	SdkSystem
+	SdkTest
+	SdkModule
+	SdkSystemServer
+	SdkPrivate
+)
+
+// String returns the string representation of this SdkKind
+func (k SdkKind) String() string {
+	switch k {
+	case SdkPrivate:
+		return "private"
+	case SdkNone:
+		return "none"
+	case SdkPublic:
+		return "public"
+	case SdkSystem:
+		return "system"
+	case SdkTest:
+		return "test"
+	case SdkCore:
+		return "core"
+	case SdkCorePlatform:
+		return "core_platform"
+	case SdkModule:
+		return "module-lib"
+	case SdkSystemServer:
+		return "system-server"
+	default:
+		return "invalid"
+	}
+}
+
+// SdkVersion represents a specific version number of an SDK spec of a particular kind
+type SdkVersion int
+
+const (
+	// special version number for a not-yet-frozen SDK
+	SdkVersionCurrent SdkVersion = SdkVersion(FutureApiLevelInt)
+	// special version number to be used for SDK specs where version number doesn't
+	// make sense, e.g. "none", "", etc.
+	SdkVersionNone SdkVersion = SdkVersion(0)
+)
+
+// IsCurrent checks if the SdkVersion refers to the not-yet-published version of an SdkKind
+func (v SdkVersion) IsCurrent() bool {
+	return v == SdkVersionCurrent
+}
+
+// IsNumbered checks if the SdkVersion refers to the published (a.k.a numbered) version of an SdkKind
+func (v SdkVersion) IsNumbered() bool {
+	return !v.IsCurrent() && v != SdkVersionNone
+}
+
+// String returns the string representation of this SdkVersion.
+func (v SdkVersion) String() string {
+	if v.IsCurrent() {
+		return "current"
+	} else if v.IsNumbered() {
+		return strconv.Itoa(int(v))
+	}
+	return "(no version)"
+}
+
+func (v SdkVersion) ApiLevel(ctx EarlyModuleContext) ApiLevel {
+	return ApiLevelOrPanic(ctx, v.String())
+}
+
+// AsNumberString directly converts the numeric value of this sdk version as a string.
+// When isNumbered() is true, this method is the same as String(). However, for SdkVersionCurrent
+// and SdkVersionNone, this returns 10000 and 0 while String() returns "current" and "(no version"),
+// respectively.
+func (v SdkVersion) AsNumberString() string {
+	return strconv.Itoa(int(v))
+}
+
+// SdkSpec represents the kind and the version of an SDK for a module to build against
+type SdkSpec struct {
+	Kind    SdkKind
+	Version SdkVersion
+	Raw     string
+}
+
+func (s SdkSpec) String() string {
+	return fmt.Sprintf("%s_%s", s.Kind, s.Version)
+}
+
+// Valid checks if this SdkSpec is well-formed. Note however that true doesn't mean that the
+// specified SDK actually exists.
+func (s SdkSpec) Valid() bool {
+	return s.Kind != SdkInvalid
+}
+
+// Specified checks if this SdkSpec is well-formed and is not "".
+func (s SdkSpec) Specified() bool {
+	return s.Valid() && s.Kind != SdkPrivate
+}
+
+// whether the API surface is managed and versioned, i.e. has .txt file that
+// get frozen on SDK freeze and changes get reviewed by API council.
+func (s SdkSpec) Stable() bool {
+	if !s.Specified() {
+		return false
+	}
+	switch s.Kind {
+	case SdkNone:
+		// there is nothing to manage and version in this case; de facto stable API.
+		return true
+	case SdkCore, SdkPublic, SdkSystem, SdkModule, SdkSystemServer:
+		return true
+	case SdkCorePlatform, SdkTest, SdkPrivate:
+		return false
+	default:
+		panic(fmt.Errorf("unknown SdkKind=%v", s.Kind))
+	}
+	return false
+}
+
+// PrebuiltSdkAvailableForUnbundledBuilt tells whether this SdkSpec can have a prebuilt SDK
+// that can be used for unbundled builds.
+func (s SdkSpec) PrebuiltSdkAvailableForUnbundledBuild() bool {
+	// "", "none", and "core_platform" are not available for unbundled build
+	// as we don't/can't have prebuilt stub for the versions
+	return s.Kind != SdkPrivate && s.Kind != SdkNone && s.Kind != SdkCorePlatform
+}
+
+func (s SdkSpec) ForVendorPartition(ctx EarlyModuleContext) SdkSpec {
+	// If BOARD_CURRENT_API_LEVEL_FOR_VENDOR_MODULES has a numeric value,
+	// use it instead of "current" for the vendor partition.
+	currentSdkVersion := ctx.DeviceConfig().CurrentApiLevelForVendorModules()
+	if currentSdkVersion == "current" {
+		return s
+	}
+
+	if s.Kind == SdkPublic || s.Kind == SdkSystem {
+		if s.Version.IsCurrent() {
+			if i, err := strconv.Atoi(currentSdkVersion); err == nil {
+				version := SdkVersion(i)
+				return SdkSpec{s.Kind, version, s.Raw}
+			}
+			panic(fmt.Errorf("BOARD_CURRENT_API_LEVEL_FOR_VENDOR_MODULES must be either \"current\" or a number, but was %q", currentSdkVersion))
+		}
+	}
+	return s
+}
+
+// UsePrebuilt determines whether prebuilt SDK should be used for this SdkSpec with the given context.
+func (s SdkSpec) UsePrebuilt(ctx EarlyModuleContext) bool {
+	if s.Version.IsCurrent() {
+		// "current" can be built from source and be from prebuilt SDK
+		return ctx.Config().AlwaysUsePrebuiltSdks()
+	} else if s.Version.IsNumbered() {
+		// validation check
+		if s.Kind != SdkPublic && s.Kind != SdkSystem && s.Kind != SdkTest && s.Kind != SdkModule {
+			panic(fmt.Errorf("prebuilt SDK is not not available for SdkKind=%q", s.Kind))
+			return false
+		}
+		// numbered SDKs are always from prebuilt
+		return true
+	}
+	// "", "none", "core_platform" fall here
+	return false
+}
+
+// EffectiveVersion converts an SdkSpec into the concrete SdkVersion that the module
+// should use. For modules targeting an unreleased SDK (meaning it does not yet have a number)
+// it returns FutureApiLevel(10000).
+func (s SdkSpec) EffectiveVersion(ctx EarlyModuleContext) (SdkVersion, error) {
+	if !s.Valid() {
+		return s.Version, fmt.Errorf("invalid sdk version %q", s.Raw)
+	}
+
+	if ctx.DeviceSpecific() || ctx.SocSpecific() {
+		s = s.ForVendorPartition(ctx)
+	}
+	if s.Version.IsNumbered() {
+		return s.Version, nil
+	}
+	return SdkVersion(ctx.Config().DefaultAppTargetSdk(ctx).FinalOrFutureInt()), nil
+}
+
+// EffectiveVersionString converts an SdkSpec into the concrete version string that the module
+// should use. For modules targeting an unreleased SDK (meaning it does not yet have a number)
+// it returns the codename (P, Q, R, etc.)
+func (s SdkSpec) EffectiveVersionString(ctx EarlyModuleContext) (string, error) {
+	ver, err := s.EffectiveVersion(ctx)
+	if err == nil && int(ver) == ctx.Config().DefaultAppTargetSdk(ctx).FinalOrFutureInt() {
+		return ctx.Config().DefaultAppTargetSdk(ctx).String(), nil
+	}
+	return ver.String(), err
+}
+
+func SdkSpecFrom(str string) SdkSpec {
+	switch str {
+	// special cases first
+	case "":
+		return SdkSpec{SdkPrivate, SdkVersionNone, str}
+	case "none":
+		return SdkSpec{SdkNone, SdkVersionNone, str}
+	case "core_platform":
+		return SdkSpec{SdkCorePlatform, SdkVersionNone, str}
+	default:
+		// the syntax is [kind_]version
+		sep := strings.LastIndex(str, "_")
+
+		var kindString string
+		if sep == 0 {
+			return SdkSpec{SdkInvalid, SdkVersionNone, str}
+		} else if sep == -1 {
+			kindString = ""
+		} else {
+			kindString = str[0:sep]
+		}
+		versionString := str[sep+1 : len(str)]
+
+		var kind SdkKind
+		switch kindString {
+		case "":
+			kind = SdkPublic
+		case "core":
+			kind = SdkCore
+		case "system":
+			kind = SdkSystem
+		case "test":
+			kind = SdkTest
+		case "module":
+			kind = SdkModule
+		case "system_server":
+			kind = SdkSystemServer
+		default:
+			return SdkSpec{SdkInvalid, SdkVersionNone, str}
+		}
+
+		var version SdkVersion
+		if versionString == "current" {
+			version = SdkVersionCurrent
+		} else if i, err := strconv.Atoi(versionString); err == nil {
+			version = SdkVersion(i)
+		} else {
+			return SdkSpec{SdkInvalid, SdkVersionNone, str}
+		}
+
+		return SdkSpec{kind, version, str}
+	}
+}
+
+func (s SdkSpec) ValidateSystemSdk(ctx EarlyModuleContext) bool {
+	// Ensures that the specified system SDK version is one of BOARD_SYSTEMSDK_VERSIONS (for vendor/product Java module)
+	// Assuming that BOARD_SYSTEMSDK_VERSIONS := 28 29,
+	// sdk_version of the modules in vendor/product that use system sdk must be either system_28, system_29 or system_current
+	if s.Kind != SdkSystem || !s.Version.IsNumbered() {
+		return true
+	}
+	allowedVersions := ctx.DeviceConfig().PlatformSystemSdkVersions()
+	if ctx.DeviceSpecific() || ctx.SocSpecific() || (ctx.ProductSpecific() && ctx.Config().EnforceProductPartitionInterface()) {
+		systemSdkVersions := ctx.DeviceConfig().SystemSdkVersions()
+		if len(systemSdkVersions) > 0 {
+			allowedVersions = systemSdkVersions
+		}
+	}
+	if len(allowedVersions) > 0 && !InList(s.Version.String(), allowedVersions) {
+		ctx.PropertyErrorf("sdk_version", "incompatible sdk version %q. System SDK version should be one of %q",
+			s.Raw, allowedVersions)
+		return false
+	}
+	return true
+}
diff --git a/apex/builder.go b/apex/builder.go
index da800d4..2df380b 100644
--- a/apex/builder.go
+++ b/apex/builder.go
@@ -950,6 +950,10 @@
 				if v := m.MinSdkVersion(); v != "" {
 					toMinSdkVersion = v
 				}
+			} else if m, ok := to.(interface{ MinSdkVersionString() string }); ok {
+				if v := m.MinSdkVersionString(); v != "" {
+					toMinSdkVersion = v
+				}
 			}
 
 			depInfos[to.Name()] = android.ApexModuleDepInfo{
diff --git a/java/aar.go b/java/aar.go
index 67b9ef0..a122a94 100644
--- a/java/aar.go
+++ b/java/aar.go
@@ -163,7 +163,7 @@
 		a.aaptProperties.RROEnforcedForDependent
 }
 
-func (a *aapt) aapt2Flags(ctx android.ModuleContext, sdkContext sdkContext,
+func (a *aapt) aapt2Flags(ctx android.ModuleContext, sdkContext android.SdkContext,
 	manifestPath android.Path) (compileFlags, linkFlags []string, linkDeps android.Paths,
 	resDirs, overlayDirs []globbedResourceDir, rroDirs []rroDir, resZips android.Paths) {
 
@@ -218,7 +218,7 @@
 	linkDeps = append(linkDeps, assetDeps...)
 
 	// SDK version flags
-	minSdkVersion, err := sdkContext.minSdkVersion().effectiveVersionString(ctx)
+	minSdkVersion, err := sdkContext.MinSdkVersion().EffectiveVersionString(ctx)
 	if err != nil {
 		ctx.ModuleErrorf("invalid minSdkVersion: %s", err)
 	}
@@ -266,7 +266,7 @@
 		CommandDeps: []string{"${config.Zip2ZipCmd}"},
 	})
 
-func (a *aapt) buildActions(ctx android.ModuleContext, sdkContext sdkContext,
+func (a *aapt) buildActions(ctx android.ModuleContext, sdkContext android.SdkContext,
 	classLoaderContexts dexpreopt.ClassLoaderContextMap, extraLinkFlags ...string) {
 
 	transitiveStaticLibs, transitiveStaticLibManifests, staticRRODirs, assetPackages, libDeps, libFlags :=
@@ -397,7 +397,7 @@
 }
 
 // aaptLibs collects libraries from dependencies and sdk_version and converts them into paths
-func aaptLibs(ctx android.ModuleContext, sdkContext sdkContext, classLoaderContexts dexpreopt.ClassLoaderContextMap) (
+func aaptLibs(ctx android.ModuleContext, sdkContext android.SdkContext, classLoaderContexts dexpreopt.ClassLoaderContextMap) (
 	transitiveStaticLibs, transitiveStaticLibManifests android.Paths, staticRRODirs []rroDir, assets, deps android.Paths, flags []string) {
 
 	var sharedLibs android.Paths
@@ -498,7 +498,7 @@
 
 func (a *AndroidLibrary) DepsMutator(ctx android.BottomUpMutatorContext) {
 	a.Module.deps(ctx)
-	sdkDep := decodeSdkDep(ctx, sdkContext(a))
+	sdkDep := decodeSdkDep(ctx, android.SdkContext(a))
 	if sdkDep.hasFrameworkLibs() {
 		a.aapt.deps(ctx, sdkDep)
 	}
@@ -507,7 +507,7 @@
 func (a *AndroidLibrary) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 	a.aapt.isLibrary = true
 	a.classLoaderContexts = make(dexpreopt.ClassLoaderContextMap)
-	a.aapt.buildActions(ctx, sdkContext(a), a.classLoaderContexts)
+	a.aapt.buildActions(ctx, android.SdkContext(a), a.classLoaderContexts)
 
 	a.hideApexVariantFromMake = !ctx.Provider(android.ApexInfoProvider).(android.ApexInfo).IsForPlatform()
 
@@ -625,23 +625,23 @@
 	}
 }
 
-func (a *AARImport) sdkVersion() sdkSpec {
-	return sdkSpecFrom(String(a.properties.Sdk_version))
+func (a *AARImport) SdkVersion() android.SdkSpec {
+	return android.SdkSpecFrom(String(a.properties.Sdk_version))
 }
 
-func (a *AARImport) systemModules() string {
+func (a *AARImport) SystemModules() string {
 	return ""
 }
 
-func (a *AARImport) minSdkVersion() sdkSpec {
+func (a *AARImport) MinSdkVersion() android.SdkSpec {
 	if a.properties.Min_sdk_version != nil {
-		return sdkSpecFrom(*a.properties.Min_sdk_version)
+		return android.SdkSpecFrom(*a.properties.Min_sdk_version)
 	}
-	return a.sdkVersion()
+	return a.SdkVersion()
 }
 
-func (a *AARImport) targetSdkVersion() sdkSpec {
-	return a.sdkVersion()
+func (a *AARImport) TargetSdkVersion() android.SdkSpec {
+	return a.SdkVersion()
 }
 
 func (a *AARImport) javaVersion() string {
@@ -700,7 +700,7 @@
 
 func (a *AARImport) DepsMutator(ctx android.BottomUpMutatorContext) {
 	if !ctx.Config().AlwaysUsePrebuiltSdks() {
-		sdkDep := decodeSdkDep(ctx, sdkContext(a))
+		sdkDep := decodeSdkDep(ctx, android.SdkContext(a))
 		if sdkDep.useModule && sdkDep.frameworkResModule != "" {
 			ctx.AddVariationDependencies(nil, frameworkResTag, sdkDep.frameworkResModule)
 		}
@@ -780,7 +780,7 @@
 	linkDeps = append(linkDeps, a.manifest)
 
 	transitiveStaticLibs, staticLibManifests, staticRRODirs, transitiveAssets, libDeps, libFlags :=
-		aaptLibs(ctx, sdkContext(a), nil)
+		aaptLibs(ctx, android.SdkContext(a), nil)
 
 	_ = staticLibManifests
 	_ = staticRRODirs
diff --git a/java/android_manifest.go b/java/android_manifest.go
index b30f3d2..6b7395b 100644
--- a/java/android_manifest.go
+++ b/java/android_manifest.go
@@ -43,7 +43,7 @@
 	"args", "libs")
 
 // Uses manifest_fixer.py to inject minSdkVersion, etc. into an AndroidManifest.xml
-func manifestFixer(ctx android.ModuleContext, manifest android.Path, sdkContext sdkContext,
+func manifestFixer(ctx android.ModuleContext, manifest android.Path, sdkContext android.SdkContext,
 	classLoaderContexts dexpreopt.ClassLoaderContextMap, isLibrary, useEmbeddedNativeLibs, usesNonSdkApis,
 	useEmbeddedDex, hasNoCode bool, loggingParent string) android.Path {
 
@@ -51,7 +51,7 @@
 	if isLibrary {
 		args = append(args, "--library")
 	} else {
-		minSdkVersion, err := sdkContext.minSdkVersion().effectiveVersion(ctx)
+		minSdkVersion, err := sdkContext.MinSdkVersion().EffectiveVersion(ctx)
 		if err != nil {
 			ctx.ModuleErrorf("invalid minSdkVersion: %s", err)
 		}
@@ -87,7 +87,7 @@
 		args = append(args, "--logging-parent", loggingParent)
 	}
 	var deps android.Paths
-	targetSdkVersion, err := sdkContext.targetSdkVersion().effectiveVersionString(ctx)
+	targetSdkVersion, err := sdkContext.TargetSdkVersion().EffectiveVersionString(ctx)
 	if err != nil {
 		ctx.ModuleErrorf("invalid targetSdkVersion: %s", err)
 	}
@@ -96,7 +96,7 @@
 		deps = append(deps, ApiFingerprintPath(ctx))
 	}
 
-	minSdkVersion, err := sdkContext.minSdkVersion().effectiveVersionString(ctx)
+	minSdkVersion, err := sdkContext.MinSdkVersion().EffectiveVersionString(ctx)
 	if err != nil {
 		ctx.ModuleErrorf("invalid minSdkVersion: %s", err)
 	}
diff --git a/java/androidmk.go b/java/androidmk.go
index 3d3eae5..75661a7 100644
--- a/java/androidmk.go
+++ b/java/androidmk.go
@@ -106,7 +106,7 @@
 					if len(library.dexpreopter.builtInstalled) > 0 {
 						entries.SetString("LOCAL_SOONG_BUILT_INSTALLED", library.dexpreopter.builtInstalled)
 					}
-					entries.SetString("LOCAL_SDK_VERSION", library.sdkVersion().raw)
+					entries.SetString("LOCAL_SDK_VERSION", library.SdkVersion().Raw)
 					entries.SetPath("LOCAL_SOONG_CLASSES_JAR", library.implementationAndResourcesJar)
 					entries.SetPath("LOCAL_SOONG_HEADER_JAR", library.headerJarFile)
 
@@ -255,7 +255,7 @@
 				entries.SetPath("LOCAL_SOONG_EXPORT_PROGUARD_FLAGS", prebuilt.proguardFlags)
 				entries.SetPath("LOCAL_SOONG_STATIC_LIBRARY_EXTRA_PACKAGES", prebuilt.extraAaptPackagesFile)
 				entries.SetPath("LOCAL_FULL_MANIFEST_FILE", prebuilt.manifest)
-				entries.SetString("LOCAL_SDK_VERSION", prebuilt.sdkVersion().raw)
+				entries.SetString("LOCAL_SDK_VERSION", prebuilt.SdkVersion().Raw)
 			},
 		},
 	}}
diff --git a/java/app.go b/java/app.go
index b849b98..ec30b49 100755
--- a/java/app.go
+++ b/java/app.go
@@ -213,16 +213,16 @@
 func (a *AndroidApp) DepsMutator(ctx android.BottomUpMutatorContext) {
 	a.Module.deps(ctx)
 
-	if String(a.appProperties.Stl) == "c++_shared" && !a.sdkVersion().specified() {
+	if String(a.appProperties.Stl) == "c++_shared" && !a.SdkVersion().Specified() {
 		ctx.PropertyErrorf("stl", "sdk_version must be set in order to use c++_shared")
 	}
 
-	sdkDep := decodeSdkDep(ctx, sdkContext(a))
+	sdkDep := decodeSdkDep(ctx, android.SdkContext(a))
 	if sdkDep.hasFrameworkLibs() {
 		a.aapt.deps(ctx, sdkDep)
 	}
 
-	usesSDK := a.sdkVersion().specified() && a.sdkVersion().kind != sdkCorePlatform
+	usesSDK := a.SdkVersion().Specified() && a.SdkVersion().Kind != android.SdkCorePlatform
 
 	if usesSDK && Bool(a.appProperties.Jni_uses_sdk_apis) {
 		ctx.PropertyErrorf("jni_uses_sdk_apis",
@@ -279,14 +279,14 @@
 
 func (a *AndroidApp) checkAppSdkVersions(ctx android.ModuleContext) {
 	if a.Updatable() {
-		if !a.sdkVersion().stable() {
-			ctx.PropertyErrorf("sdk_version", "Updatable apps must use stable SDKs, found %v", a.sdkVersion())
+		if !a.SdkVersion().Stable() {
+			ctx.PropertyErrorf("sdk_version", "Updatable apps must use stable SDKs, found %v", a.SdkVersion())
 		}
 		if String(a.deviceProperties.Min_sdk_version) == "" {
 			ctx.PropertyErrorf("updatable", "updatable apps must set min_sdk_version.")
 		}
 
-		if minSdkVersion, err := a.minSdkVersion().effectiveVersion(ctx); err == nil {
+		if minSdkVersion, err := a.MinSdkVersion().EffectiveVersion(ctx); err == nil {
 			a.checkJniLibsSdkVersion(ctx, minSdkVersion)
 			android.CheckMinSdkVersion(a, ctx, minSdkVersion.ApiLevel(ctx))
 		} else {
@@ -304,7 +304,7 @@
 // because, sdk_version is overridden by min_sdk_version (if set as smaller)
 // and sdkLinkType is checked with dependencies so we can be sure that the whole dependency tree
 // will meet the requirements.
-func (a *AndroidApp) checkJniLibsSdkVersion(ctx android.ModuleContext, minSdkVersion sdkVersion) {
+func (a *AndroidApp) checkJniLibsSdkVersion(ctx android.ModuleContext, minSdkVersion android.SdkVersion) {
 	// It's enough to check direct JNI deps' sdk_version because all transitive deps from JNI deps are checked in cc.checkLinkType()
 	ctx.VisitDirectDeps(func(m android.Module) {
 		if !IsJniDepTag(ctx.OtherModuleDependencyTag(m)) {
@@ -312,9 +312,9 @@
 		}
 		dep, _ := m.(*cc.Module)
 		// The domain of cc.sdk_version is "current" and <number>
-		// We can rely on sdkSpec to convert it to <number> so that "current" is handled
-		// properly regardless of sdk finalization.
-		jniSdkVersion, err := sdkSpecFrom(dep.SdkVersion()).effectiveVersion(ctx)
+		// We can rely on android.SdkSpec to convert it to <number> so that "current" is
+		// handled properly regardless of sdk finalization.
+		jniSdkVersion, err := android.SdkSpecFrom(dep.SdkVersion()).EffectiveVersion(ctx)
 		if err != nil || minSdkVersion < jniSdkVersion {
 			ctx.OtherModuleErrorf(dep, "sdk_version(%v) is higher than min_sdk_version(%v) of the containing android_app(%v)",
 				dep.SdkVersion(), minSdkVersion, ctx.ModuleName())
@@ -327,9 +327,9 @@
 // Returns true if the native libraries should be stored in the APK uncompressed and the
 // extractNativeLibs application flag should be set to false in the manifest.
 func (a *AndroidApp) useEmbeddedNativeLibs(ctx android.ModuleContext) bool {
-	minSdkVersion, err := a.minSdkVersion().effectiveVersion(ctx)
+	minSdkVersion, err := a.MinSdkVersion().EffectiveVersion(ctx)
 	if err != nil {
-		ctx.PropertyErrorf("min_sdk_version", "invalid value %q: %s", a.minSdkVersion(), err)
+		ctx.PropertyErrorf("min_sdk_version", "invalid value %q: %s", a.MinSdkVersion(), err)
 	}
 
 	apexInfo := ctx.Provider(android.ApexInfoProvider).(android.ApexInfo)
@@ -419,7 +419,7 @@
 
 	a.aapt.splitNames = a.appProperties.Package_splits
 	a.aapt.LoggingParent = String(a.overridableAppProperties.Logging_parent)
-	a.aapt.buildActions(ctx, sdkContext(a), a.classLoaderContexts, aaptLinkFlags...)
+	a.aapt.buildActions(ctx, android.SdkContext(a), a.classLoaderContexts, aaptLinkFlags...)
 
 	// apps manifests are handled by aapt, don't let Module see them
 	a.properties.Manifest = nil
@@ -720,8 +720,8 @@
 }
 
 type appDepsInterface interface {
-	sdkVersion() sdkSpec
-	minSdkVersion() sdkSpec
+	SdkVersion() android.SdkSpec
+	MinSdkVersion() android.SdkSpec
 	RequiresStableAPIs(ctx android.BaseModuleContext) bool
 }
 
@@ -734,8 +734,8 @@
 	seenModulePaths := make(map[string]bool)
 
 	if checkNativeSdkVersion {
-		checkNativeSdkVersion = app.sdkVersion().specified() &&
-			app.sdkVersion().kind != sdkCorePlatform && !app.RequiresStableAPIs(ctx)
+		checkNativeSdkVersion = app.SdkVersion().Specified() &&
+			app.SdkVersion().Kind != android.SdkCorePlatform && !app.RequiresStableAPIs(ctx)
 	}
 
 	ctx.WalkDeps(func(module android.Module, parent android.Module) bool {
@@ -829,6 +829,10 @@
 				if v := m.MinSdkVersion(); v != "" {
 					toMinSdkVersion = v
 				}
+			} else if m, ok := to.(interface{ MinSdkVersionString() string }); ok {
+				if v := m.MinSdkVersionString(); v != "" {
+					toMinSdkVersion = v
+				}
 			}
 			depsInfo[depName] = android.ApexModuleDepInfo{
 				To:            depName,
@@ -840,7 +844,7 @@
 		return true
 	})
 
-	a.ApexBundleDepsInfo.BuildDepsInfoLists(ctx, a.MinSdkVersion(), depsInfo)
+	a.ApexBundleDepsInfo.BuildDepsInfoLists(ctx, a.MinSdkVersionString(), depsInfo)
 }
 
 func (a *AndroidApp) Updatable() bool {
diff --git a/java/app_import.go b/java/app_import.go
index d4da64d..32cec23 100644
--- a/java/app_import.go
+++ b/java/app_import.go
@@ -394,12 +394,12 @@
 	return false
 }
 
-func (a *AndroidAppImport) sdkVersion() sdkSpec {
-	return sdkSpecFrom("")
+func (a *AndroidAppImport) SdkVersion() android.SdkSpec {
+	return android.SdkSpecFrom("")
 }
 
-func (a *AndroidAppImport) minSdkVersion() sdkSpec {
-	return sdkSpecFrom("")
+func (a *AndroidAppImport) MinSdkVersion() android.SdkSpec {
+	return android.SdkSpecFrom("")
 }
 
 var _ android.ApexModule = (*AndroidAppImport)(nil)
diff --git a/java/base.go b/java/base.go
index bd394af..73e5352 100644
--- a/java/base.go
+++ b/java/base.go
@@ -373,11 +373,11 @@
 }
 
 func (j *Module) CheckStableSdkVersion() error {
-	sdkVersion := j.sdkVersion()
-	if sdkVersion.stable() {
+	sdkVersion := j.SdkVersion()
+	if sdkVersion.Stable() {
 		return nil
 	}
-	if sdkVersion.kind == sdkCorePlatform {
+	if sdkVersion.Kind == android.SdkCorePlatform {
 		if useLegacyCorePlatformApiByName(j.BaseModuleName()) {
 			return fmt.Errorf("non stable SDK %v - uses legacy core platform", sdkVersion)
 		} else {
@@ -392,8 +392,8 @@
 // checkSdkVersions enforces restrictions around SDK dependencies.
 func (j *Module) checkSdkVersions(ctx android.ModuleContext) {
 	if j.RequiresStableAPIs(ctx) {
-		if sc, ok := ctx.Module().(sdkContext); ok {
-			if !sc.sdkVersion().specified() {
+		if sc, ok := ctx.Module().(android.SdkContext); ok {
+			if !sc.SdkVersion().Specified() {
 				ctx.PropertyErrorf("sdk_version",
 					"sdk_version must have a value when the module is located at vendor or product(only if PRODUCT_ENFORCE_PRODUCT_PARTITION_INTERFACE is set).")
 			}
@@ -416,9 +416,9 @@
 }
 
 func (j *Module) checkPlatformAPI(ctx android.ModuleContext) {
-	if sc, ok := ctx.Module().(sdkContext); ok {
+	if sc, ok := ctx.Module().(android.SdkContext); ok {
 		usePlatformAPI := proptools.Bool(j.deviceProperties.Platform_apis)
-		sdkVersionSpecified := sc.sdkVersion().specified()
+		sdkVersionSpecified := sc.SdkVersion().Specified()
 		if usePlatformAPI && sdkVersionSpecified {
 			ctx.PropertyErrorf("platform_apis", "platform_apis must be false when sdk_version is not empty.")
 		} else if !usePlatformAPI && !sdkVersionSpecified {
@@ -512,30 +512,30 @@
 	return false
 }
 
-func (j *Module) sdkVersion() sdkSpec {
-	return sdkSpecFrom(String(j.deviceProperties.Sdk_version))
+func (j *Module) SdkVersion() android.SdkSpec {
+	return android.SdkSpecFrom(String(j.deviceProperties.Sdk_version))
 }
 
-func (j *Module) systemModules() string {
+func (j *Module) SystemModules() string {
 	return proptools.String(j.deviceProperties.System_modules)
 }
 
-func (j *Module) minSdkVersion() sdkSpec {
+func (j *Module) MinSdkVersion() android.SdkSpec {
 	if j.deviceProperties.Min_sdk_version != nil {
-		return sdkSpecFrom(*j.deviceProperties.Min_sdk_version)
+		return android.SdkSpecFrom(*j.deviceProperties.Min_sdk_version)
 	}
-	return j.sdkVersion()
+	return j.SdkVersion()
 }
 
-func (j *Module) targetSdkVersion() sdkSpec {
+func (j *Module) TargetSdkVersion() android.SdkSpec {
 	if j.deviceProperties.Target_sdk_version != nil {
-		return sdkSpecFrom(*j.deviceProperties.Target_sdk_version)
+		return android.SdkSpecFrom(*j.deviceProperties.Target_sdk_version)
 	}
-	return j.sdkVersion()
+	return j.SdkVersion()
 }
 
-func (j *Module) MinSdkVersion() string {
-	return j.minSdkVersion().version.String()
+func (j *Module) MinSdkVersionString() string {
+	return j.MinSdkVersion().Version.String()
 }
 
 func (j *Module) AvailableFor(what string) bool {
@@ -552,7 +552,7 @@
 	if ctx.Device() {
 		j.linter.deps(ctx)
 
-		sdkDeps(ctx, sdkContext(j), j.dexer)
+		sdkDeps(ctx, android.SdkContext(j), j.dexer)
 
 		if j.deviceProperties.SyspropPublicStub != "" {
 			// This is a sysprop implementation library that has a corresponding sysprop public
@@ -702,7 +702,7 @@
 	var flags javaBuilderFlags
 
 	// javaVersion flag.
-	flags.javaVersion = getJavaVersion(ctx, String(j.properties.Java_version), sdkContext(j))
+	flags.javaVersion = getJavaVersion(ctx, String(j.properties.Java_version), android.SdkContext(j))
 
 	if ctx.Config().RunErrorProne() {
 		if config.ErrorProneClasspath == nil && ctx.Config().TestProductVariables == nil {
@@ -731,7 +731,7 @@
 	flags.processors = android.FirstUniqueStrings(flags.processors)
 
 	if len(flags.bootClasspath) == 0 && ctx.Host() && !flags.javaVersion.usesJavaModules() &&
-		decodeSdkDep(ctx, sdkContext(j)).hasStandardLibs() {
+		decodeSdkDep(ctx, android.SdkContext(j)).hasStandardLibs() {
 		// Give host-side tools a version of OpenJDK's standard libraries
 		// close to what they're targeting. As of Dec 2017, AOSP is only
 		// bundling OpenJDK 8 and 9, so nothing < 8 is available.
@@ -1209,7 +1209,7 @@
 			}
 			// Dex compilation
 			var dexOutputFile android.OutputPath
-			dexOutputFile = j.dexer.compileDex(ctx, flags, j.minSdkVersion(), outputFile, jarName)
+			dexOutputFile = j.dexer.compileDex(ctx, flags, j.MinSdkVersion(), outputFile, jarName)
 			if ctx.Failed() {
 				return
 			}
@@ -1254,8 +1254,8 @@
 	}
 
 	if ctx.Device() {
-		lintSDKVersionString := func(sdkSpec sdkSpec) string {
-			if v := sdkSpec.version; v.isNumbered() {
+		lintSDKVersionString := func(sdkSpec android.SdkSpec) string {
+			if v := sdkSpec.Version; v.IsNumbered() {
 				return v.String()
 			} else {
 				return ctx.Config().DefaultAppTargetSdk(ctx).String()
@@ -1267,9 +1267,9 @@
 		j.linter.srcJars = srcJars
 		j.linter.classpath = append(append(android.Paths(nil), flags.bootClasspath...), flags.classpath...)
 		j.linter.classes = j.implementationJarFile
-		j.linter.minSdkVersion = lintSDKVersionString(j.minSdkVersion())
-		j.linter.targetSdkVersion = lintSDKVersionString(j.targetSdkVersion())
-		j.linter.compileSdkVersion = lintSDKVersionString(j.sdkVersion())
+		j.linter.minSdkVersion = lintSDKVersionString(j.MinSdkVersion())
+		j.linter.targetSdkVersion = lintSDKVersionString(j.TargetSdkVersion())
+		j.linter.compileSdkVersion = lintSDKVersionString(j.SdkVersion())
 		j.linter.javaLanguageLevel = flags.javaVersion.String()
 		j.linter.kotlinLanguageLevel = "1.3"
 		if !apexInfo.IsForPlatform() && ctx.Config().UnbundledBuildApps() {
@@ -1471,14 +1471,14 @@
 // Implements android.ApexModule
 func (j *Module) ShouldSupportSdkVersion(ctx android.BaseModuleContext,
 	sdkVersion android.ApiLevel) error {
-	sdkSpec := j.minSdkVersion()
-	if !sdkSpec.specified() {
+	sdkSpec := j.MinSdkVersion()
+	if !sdkSpec.Specified() {
 		return fmt.Errorf("min_sdk_version is not specified")
 	}
-	if sdkSpec.kind == sdkCore {
+	if sdkSpec.Kind == android.SdkCore {
 		return nil
 	}
-	ver, err := sdkSpec.effectiveVersion(ctx)
+	ver, err := sdkSpec.EffectiveVersion(ctx)
 	if err != nil {
 		return err
 	}
@@ -1576,24 +1576,24 @@
 		return linkType, true
 	}
 
-	ver := m.sdkVersion()
-	switch ver.kind {
-	case sdkCore:
+	ver := m.SdkVersion()
+	switch ver.Kind {
+	case android.SdkCore:
 		return javaCore, false
-	case sdkSystem:
+	case android.SdkSystem:
 		return javaSystem, false
-	case sdkPublic:
+	case android.SdkPublic:
 		return javaSdk, false
-	case sdkModule:
+	case android.SdkModule:
 		return javaModule, false
-	case sdkSystemServer:
+	case android.SdkSystemServer:
 		return javaSystemServer, false
-	case sdkPrivate, sdkNone, sdkCorePlatform, sdkTest:
+	case android.SdkPrivate, android.SdkNone, android.SdkCorePlatform, android.SdkTest:
 		return javaPlatform, false
 	}
 
-	if !ver.valid() {
-		panic(fmt.Errorf("sdk_version is invalid. got %q", ver.raw))
+	if !ver.Valid() {
+		panic(fmt.Errorf("sdk_version is invalid. got %q", ver.Raw))
 	}
 	return javaSdk, false
 }
@@ -1625,7 +1625,7 @@
 	var deps deps
 
 	if ctx.Device() {
-		sdkDep := decodeSdkDep(ctx, sdkContext(j))
+		sdkDep := decodeSdkDep(ctx, android.SdkContext(j))
 		if sdkDep.invalidVersion {
 			ctx.AddMissingDependencies(sdkDep.bootclasspath)
 			ctx.AddMissingDependencies(sdkDep.java9Classpath)
@@ -1656,7 +1656,7 @@
 		if dep, ok := module.(SdkLibraryDependency); ok {
 			switch tag {
 			case libTag:
-				deps.classpath = append(deps.classpath, dep.SdkHeaderJars(ctx, j.sdkVersion())...)
+				deps.classpath = append(deps.classpath, dep.SdkHeaderJars(ctx, j.SdkVersion())...)
 			case staticLibTag:
 				ctx.ModuleErrorf("dependency on java_sdk_library %q can only be in libs", otherName)
 			}
diff --git a/java/dex.go b/java/dex.go
index b042f13..5c6d41d 100644
--- a/java/dex.go
+++ b/java/dex.go
@@ -157,7 +157,7 @@
 	}, []string{"outDir", "outDict", "outUsage", "outUsageZip", "outUsageDir",
 		"r8Flags", "zipFlags"}, []string{"implicits"})
 
-func (d *dexer) dexCommonFlags(ctx android.ModuleContext, minSdkVersion sdkSpec) []string {
+func (d *dexer) dexCommonFlags(ctx android.ModuleContext, minSdkVersion android.SdkSpec) []string {
 	flags := d.dexProperties.Dxflags
 	// Translate all the DX flags to D8 ones until all the build files have been migrated
 	// to D8 flags. See: b/69377755
@@ -174,12 +174,12 @@
 			"--verbose")
 	}
 
-	effectiveVersion, err := minSdkVersion.effectiveVersion(ctx)
+	effectiveVersion, err := minSdkVersion.EffectiveVersion(ctx)
 	if err != nil {
 		ctx.PropertyErrorf("min_sdk_version", "%s", err)
 	}
 
-	flags = append(flags, "--min-api "+effectiveVersion.asNumberString())
+	flags = append(flags, "--min-api "+effectiveVersion.AsNumberString())
 	return flags
 }
 
@@ -266,7 +266,7 @@
 	return r8Flags, r8Deps
 }
 
-func (d *dexer) compileDex(ctx android.ModuleContext, flags javaBuilderFlags, minSdkVersion sdkSpec,
+func (d *dexer) compileDex(ctx android.ModuleContext, flags javaBuilderFlags, minSdkVersion android.SdkSpec,
 	classesJar android.Path, jarName string) android.OutputPath {
 
 	// Compile classes.jar into classes.dex and then javalib.jar
diff --git a/java/droiddoc.go b/java/droiddoc.go
index f7595b1..a0d99a7 100644
--- a/java/droiddoc.go
+++ b/java/droiddoc.go
@@ -265,25 +265,25 @@
 
 var _ android.OutputFileProducer = (*Javadoc)(nil)
 
-func (j *Javadoc) sdkVersion() sdkSpec {
-	return sdkSpecFrom(String(j.properties.Sdk_version))
+func (j *Javadoc) SdkVersion() android.SdkSpec {
+	return android.SdkSpecFrom(String(j.properties.Sdk_version))
 }
 
-func (j *Javadoc) systemModules() string {
+func (j *Javadoc) SystemModules() string {
 	return proptools.String(j.properties.System_modules)
 }
 
-func (j *Javadoc) minSdkVersion() sdkSpec {
-	return j.sdkVersion()
+func (j *Javadoc) MinSdkVersion() android.SdkSpec {
+	return j.SdkVersion()
 }
 
-func (j *Javadoc) targetSdkVersion() sdkSpec {
-	return j.sdkVersion()
+func (j *Javadoc) TargetSdkVersion() android.SdkSpec {
+	return j.SdkVersion()
 }
 
 func (j *Javadoc) addDeps(ctx android.BottomUpMutatorContext) {
 	if ctx.Device() {
-		sdkDep := decodeSdkDep(ctx, sdkContext(j))
+		sdkDep := decodeSdkDep(ctx, android.SdkContext(j))
 		if sdkDep.useModule {
 			ctx.AddVariationDependencies(nil, bootClasspathTag, sdkDep.bootclasspath...)
 			ctx.AddVariationDependencies(nil, systemModulesTag, sdkDep.systemModules)
@@ -361,7 +361,7 @@
 func (j *Javadoc) collectDeps(ctx android.ModuleContext) deps {
 	var deps deps
 
-	sdkDep := decodeSdkDep(ctx, sdkContext(j))
+	sdkDep := decodeSdkDep(ctx, android.SdkContext(j))
 	if sdkDep.invalidVersion {
 		ctx.AddMissingDependencies(sdkDep.bootclasspath)
 		ctx.AddMissingDependencies(sdkDep.java9Classpath)
@@ -390,7 +390,7 @@
 			}
 		case libTag:
 			if dep, ok := module.(SdkLibraryDependency); ok {
-				deps.classpath = append(deps.classpath, dep.SdkHeaderJars(ctx, j.sdkVersion())...)
+				deps.classpath = append(deps.classpath, dep.SdkHeaderJars(ctx, j.SdkVersion())...)
 			} else if ctx.OtherModuleHasProvider(module, JavaInfoProvider) {
 				dep := ctx.OtherModuleProvider(module, JavaInfoProvider).(JavaInfo)
 				deps.classpath = append(deps.classpath, dep.HeaderJars...)
@@ -555,7 +555,7 @@
 
 	srcJarList := zipSyncCmd(ctx, rule, srcJarDir, j.srcJars)
 
-	javaVersion := getJavaVersion(ctx, String(j.properties.Java_version), sdkContext(j))
+	javaVersion := getJavaVersion(ctx, String(j.properties.Java_version), android.SdkContext(j))
 
 	cmd := javadocSystemModulesCmd(ctx, rule, j.srcFiles, outDir, srcJarDir, srcJarList,
 		deps.systemModules, deps.classpath, j.sourcepaths)
diff --git a/java/droidstubs.go b/java/droidstubs.go
index d7a0668..3469616 100644
--- a/java/droidstubs.go
+++ b/java/droidstubs.go
@@ -474,7 +474,7 @@
 func (d *Droidstubs) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 	deps := d.Javadoc.collectDeps(ctx)
 
-	javaVersion := getJavaVersion(ctx, String(d.Javadoc.properties.Java_version), sdkContext(d))
+	javaVersion := getJavaVersion(ctx, String(d.Javadoc.properties.Java_version), android.SdkContext(d))
 
 	// Create rule for metalava
 
diff --git a/java/java.go b/java/java.go
index 3ffe572..5fe8814 100644
--- a/java/java.go
+++ b/java/java.go
@@ -304,7 +304,7 @@
 	unstrippedFile android.Path
 }
 
-func sdkDeps(ctx android.BottomUpMutatorContext, sdkContext sdkContext, d dexer) {
+func sdkDeps(ctx android.BottomUpMutatorContext, sdkContext android.SdkContext, d dexer) {
 	sdkDep := decodeSdkDep(ctx, sdkContext)
 	if sdkDep.useModule {
 		ctx.AddVariationDependencies(nil, bootClasspathTag, sdkDep.bootclasspath...)
@@ -352,11 +352,11 @@
 	}
 }
 
-func getJavaVersion(ctx android.ModuleContext, javaVersion string, sdkContext sdkContext) javaVersion {
+func getJavaVersion(ctx android.ModuleContext, javaVersion string, sdkContext android.SdkContext) javaVersion {
 	if javaVersion != "" {
 		return normalizeJavaVersion(ctx, javaVersion)
 	} else if ctx.Device() {
-		return sdkContext.sdkVersion().defaultJavaLanguageVersion(ctx)
+		return defaultJavaLanguageVersion(ctx, sdkContext.SdkVersion())
 	} else {
 		return JAVA_VERSION_9
 	}
@@ -1132,31 +1132,31 @@
 	hideApexVariantFromMake bool
 }
 
-func (j *Import) sdkVersion() sdkSpec {
-	return sdkSpecFrom(String(j.properties.Sdk_version))
+func (j *Import) SdkVersion() android.SdkSpec {
+	return android.SdkSpecFrom(String(j.properties.Sdk_version))
 }
 
 func (j *Import) makeSdkVersion() string {
-	return j.sdkVersion().raw
+	return j.SdkVersion().Raw
 }
 
-func (j *Import) systemModules() string {
+func (j *Import) SystemModules() string {
 	return "none"
 }
 
-func (j *Import) minSdkVersion() sdkSpec {
+func (j *Import) MinSdkVersion() android.SdkSpec {
 	if j.properties.Min_sdk_version != nil {
-		return sdkSpecFrom(*j.properties.Min_sdk_version)
+		return android.SdkSpecFrom(*j.properties.Min_sdk_version)
 	}
-	return j.sdkVersion()
+	return j.SdkVersion()
 }
 
-func (j *Import) targetSdkVersion() sdkSpec {
-	return j.sdkVersion()
+func (j *Import) TargetSdkVersion() android.SdkSpec {
+	return j.SdkVersion()
 }
 
-func (j *Import) MinSdkVersion() string {
-	return j.minSdkVersion().version.String()
+func (j *Import) MinSdkVersionString() string {
+	return j.MinSdkVersion().Version.String()
 }
 
 func (j *Import) Prebuilt() *android.Prebuilt {
@@ -1187,7 +1187,7 @@
 	ctx.AddVariationDependencies(nil, libTag, j.properties.Libs...)
 
 	if ctx.Device() && Bool(j.dexProperties.Compile_dex) {
-		sdkDeps(ctx, sdkContext(j), j.dexer)
+		sdkDeps(ctx, android.SdkContext(j), j.dexer)
 	}
 }
 
@@ -1230,7 +1230,7 @@
 		} else if dep, ok := module.(SdkLibraryDependency); ok {
 			switch tag {
 			case libTag:
-				flags.classpath = append(flags.classpath, dep.SdkHeaderJars(ctx, j.sdkVersion())...)
+				flags.classpath = append(flags.classpath, dep.SdkHeaderJars(ctx, j.SdkVersion())...)
 			}
 		}
 
@@ -1272,7 +1272,7 @@
 				ctx.ModuleErrorf("internal error: no dex implementation jar available from prebuilt_apex %q", deapexerModule.Name())
 			}
 		} else if Bool(j.dexProperties.Compile_dex) {
-			sdkDep := decodeSdkDep(ctx, sdkContext(j))
+			sdkDep := decodeSdkDep(ctx, android.SdkContext(j))
 			if sdkDep.invalidVersion {
 				ctx.AddMissingDependencies(sdkDep.bootclasspath)
 				ctx.AddMissingDependencies(sdkDep.java9Classpath)
@@ -1291,7 +1291,7 @@
 			j.dexpreopter.uncompressedDex = *j.dexProperties.Uncompress_dex
 
 			var dexOutputFile android.OutputPath
-			dexOutputFile = j.dexer.compileDex(ctx, flags, j.minSdkVersion(), outputFile, jarName)
+			dexOutputFile = j.dexer.compileDex(ctx, flags, j.MinSdkVersion(), outputFile, jarName)
 			if ctx.Failed() {
 				return
 			}
@@ -1359,14 +1359,14 @@
 // Implements android.ApexModule
 func (j *Import) ShouldSupportSdkVersion(ctx android.BaseModuleContext,
 	sdkVersion android.ApiLevel) error {
-	sdkSpec := j.minSdkVersion()
-	if !sdkSpec.specified() {
+	sdkSpec := j.MinSdkVersion()
+	if !sdkSpec.Specified() {
 		return fmt.Errorf("min_sdk_version is not specified")
 	}
-	if sdkSpec.kind == sdkCore {
+	if sdkSpec.Kind == android.SdkCore {
 		return nil
 	}
-	ver, err := sdkSpec.effectiveVersion(ctx)
+	ver, err := sdkSpec.EffectiveVersion(ctx)
 	if err != nil {
 		return err
 	}
diff --git a/java/rro.go b/java/rro.go
index aafa88e..4ae0014 100644
--- a/java/rro.go
+++ b/java/rro.go
@@ -91,7 +91,7 @@
 }
 
 func (r *RuntimeResourceOverlay) DepsMutator(ctx android.BottomUpMutatorContext) {
-	sdkDep := decodeSdkDep(ctx, sdkContext(r))
+	sdkDep := decodeSdkDep(ctx, android.SdkContext(r))
 	if sdkDep.hasFrameworkLibs() {
 		r.aapt.deps(ctx, sdkDep)
 	}
@@ -141,23 +141,23 @@
 	ctx.InstallFile(r.installDir, r.outputFile.Base(), r.outputFile)
 }
 
-func (r *RuntimeResourceOverlay) sdkVersion() sdkSpec {
-	return sdkSpecFrom(String(r.properties.Sdk_version))
+func (r *RuntimeResourceOverlay) SdkVersion() android.SdkSpec {
+	return android.SdkSpecFrom(String(r.properties.Sdk_version))
 }
 
-func (r *RuntimeResourceOverlay) systemModules() string {
+func (r *RuntimeResourceOverlay) SystemModules() string {
 	return ""
 }
 
-func (r *RuntimeResourceOverlay) minSdkVersion() sdkSpec {
+func (r *RuntimeResourceOverlay) MinSdkVersion() android.SdkSpec {
 	if r.properties.Min_sdk_version != nil {
-		return sdkSpecFrom(*r.properties.Min_sdk_version)
+		return android.SdkSpecFrom(*r.properties.Min_sdk_version)
 	}
-	return r.sdkVersion()
+	return r.SdkVersion()
 }
 
-func (r *RuntimeResourceOverlay) targetSdkVersion() sdkSpec {
-	return r.sdkVersion()
+func (r *RuntimeResourceOverlay) TargetSdkVersion() android.SdkSpec {
+	return r.SdkVersion()
 }
 
 func (r *RuntimeResourceOverlay) Certificate() Certificate {
diff --git a/java/sdk.go b/java/sdk.go
index 74d5a81..b546ca0 100644
--- a/java/sdk.go
+++ b/java/sdk.go
@@ -19,7 +19,6 @@
 	"path/filepath"
 	"sort"
 	"strconv"
-	"strings"
 
 	"android/soong/android"
 	"android/soong/java/config"
@@ -38,19 +37,6 @@
 var nonUpdatableFrameworkAidlPathKey = android.NewOnceKey("nonUpdatableFrameworkAidlPathKey")
 var apiFingerprintPathKey = android.NewOnceKey("apiFingerprintPathKey")
 
-type sdkContext interface {
-	// sdkVersion returns sdkSpec that corresponds to the sdk_version property of the current module
-	sdkVersion() sdkSpec
-	// systemModules returns the system_modules property of the current module, or an empty string if it is not set.
-	systemModules() string
-	// minSdkVersion returns sdkSpec that corresponds to the min_sdk_version property of the current module,
-	// or from sdk_version if it is not set.
-	minSdkVersion() sdkSpec
-	// targetSdkVersion returns the sdkSpec that corresponds to the target_sdk_version property of the current module,
-	// or from sdk_version if it is not set.
-	targetSdkVersion() sdkSpec
-}
-
 func UseApiFingerprint(ctx android.BaseModuleContext) bool {
 	if ctx.Config().UnbundledBuild() &&
 		!ctx.Config().AlwaysUsePrebuiltSdks() &&
@@ -60,209 +46,8 @@
 	return false
 }
 
-// sdkKind represents a particular category of an SDK spec like public, system, test, etc.
-type sdkKind int
-
-const (
-	sdkInvalid sdkKind = iota
-	sdkNone
-	sdkCore
-	sdkCorePlatform
-	sdkPublic
-	sdkSystem
-	sdkTest
-	sdkModule
-	sdkSystemServer
-	sdkPrivate
-)
-
-// String returns the string representation of this sdkKind
-func (k sdkKind) String() string {
-	switch k {
-	case sdkPrivate:
-		return "private"
-	case sdkNone:
-		return "none"
-	case sdkPublic:
-		return "public"
-	case sdkSystem:
-		return "system"
-	case sdkTest:
-		return "test"
-	case sdkCore:
-		return "core"
-	case sdkCorePlatform:
-		return "core_platform"
-	case sdkModule:
-		return "module-lib"
-	case sdkSystemServer:
-		return "system-server"
-	default:
-		return "invalid"
-	}
-}
-
-// sdkVersion represents a specific version number of an SDK spec of a particular kind
-type sdkVersion int
-
-const (
-	// special version number for a not-yet-frozen SDK
-	sdkVersionCurrent sdkVersion = sdkVersion(android.FutureApiLevelInt)
-	// special version number to be used for SDK specs where version number doesn't
-	// make sense, e.g. "none", "", etc.
-	sdkVersionNone sdkVersion = sdkVersion(0)
-)
-
-// isCurrent checks if the sdkVersion refers to the not-yet-published version of an sdkKind
-func (v sdkVersion) isCurrent() bool {
-	return v == sdkVersionCurrent
-}
-
-// isNumbered checks if the sdkVersion refers to the published (a.k.a numbered) version of an sdkKind
-func (v sdkVersion) isNumbered() bool {
-	return !v.isCurrent() && v != sdkVersionNone
-}
-
-// String returns the string representation of this sdkVersion.
-func (v sdkVersion) String() string {
-	if v.isCurrent() {
-		return "current"
-	} else if v.isNumbered() {
-		return strconv.Itoa(int(v))
-	}
-	return "(no version)"
-}
-
-func (v sdkVersion) ApiLevel(ctx android.EarlyModuleContext) android.ApiLevel {
-	return android.ApiLevelOrPanic(ctx, v.String())
-}
-
-// asNumberString directly converts the numeric value of this sdk version as a string.
-// When isNumbered() is true, this method is the same as String(). However, for sdkVersionCurrent
-// and sdkVersionNone, this returns 10000 and 0 while String() returns "current" and "(no version"),
-// respectively.
-func (v sdkVersion) asNumberString() string {
-	return strconv.Itoa(int(v))
-}
-
-// sdkSpec represents the kind and the version of an SDK for a module to build against
-type sdkSpec struct {
-	kind    sdkKind
-	version sdkVersion
-	raw     string
-}
-
-func (s sdkSpec) String() string {
-	return fmt.Sprintf("%s_%s", s.kind, s.version)
-}
-
-// valid checks if this sdkSpec is well-formed. Note however that true doesn't mean that the
-// specified SDK actually exists.
-func (s sdkSpec) valid() bool {
-	return s.kind != sdkInvalid
-}
-
-// specified checks if this sdkSpec is well-formed and is not "".
-func (s sdkSpec) specified() bool {
-	return s.valid() && s.kind != sdkPrivate
-}
-
-// whether the API surface is managed and versioned, i.e. has .txt file that
-// get frozen on SDK freeze and changes get reviewed by API council.
-func (s sdkSpec) stable() bool {
-	if !s.specified() {
-		return false
-	}
-	switch s.kind {
-	case sdkNone:
-		// there is nothing to manage and version in this case; de facto stable API.
-		return true
-	case sdkCore, sdkPublic, sdkSystem, sdkModule, sdkSystemServer:
-		return true
-	case sdkCorePlatform, sdkTest, sdkPrivate:
-		return false
-	default:
-		panic(fmt.Errorf("unknown sdkKind=%v", s.kind))
-	}
-	return false
-}
-
-// prebuiltSdkAvailableForUnbundledBuilt tells whether this sdkSpec can have a prebuilt SDK
-// that can be used for unbundled builds.
-func (s sdkSpec) prebuiltSdkAvailableForUnbundledBuild() bool {
-	// "", "none", and "core_platform" are not available for unbundled build
-	// as we don't/can't have prebuilt stub for the versions
-	return s.kind != sdkPrivate && s.kind != sdkNone && s.kind != sdkCorePlatform
-}
-
-func (s sdkSpec) forVendorPartition(ctx android.EarlyModuleContext) sdkSpec {
-	// If BOARD_CURRENT_API_LEVEL_FOR_VENDOR_MODULES has a numeric value,
-	// use it instead of "current" for the vendor partition.
-	currentSdkVersion := ctx.DeviceConfig().CurrentApiLevelForVendorModules()
-	if currentSdkVersion == "current" {
-		return s
-	}
-
-	if s.kind == sdkPublic || s.kind == sdkSystem {
-		if s.version.isCurrent() {
-			if i, err := strconv.Atoi(currentSdkVersion); err == nil {
-				version := sdkVersion(i)
-				return sdkSpec{s.kind, version, s.raw}
-			}
-			panic(fmt.Errorf("BOARD_CURRENT_API_LEVEL_FOR_VENDOR_MODULES must be either \"current\" or a number, but was %q", currentSdkVersion))
-		}
-	}
-	return s
-}
-
-// usePrebuilt determines whether prebuilt SDK should be used for this sdkSpec with the given context.
-func (s sdkSpec) usePrebuilt(ctx android.EarlyModuleContext) bool {
-	if s.version.isCurrent() {
-		// "current" can be built from source and be from prebuilt SDK
-		return ctx.Config().AlwaysUsePrebuiltSdks()
-	} else if s.version.isNumbered() {
-		// validation check
-		if s.kind != sdkPublic && s.kind != sdkSystem && s.kind != sdkTest && s.kind != sdkModule {
-			panic(fmt.Errorf("prebuilt SDK is not not available for sdkKind=%q", s.kind))
-			return false
-		}
-		// numbered SDKs are always from prebuilt
-		return true
-	}
-	// "", "none", "core_platform" fall here
-	return false
-}
-
-// effectiveVersion converts an sdkSpec into the concrete sdkVersion that the module
-// should use. For modules targeting an unreleased SDK (meaning it does not yet have a number)
-// it returns android.FutureApiLevel(10000).
-func (s sdkSpec) effectiveVersion(ctx android.EarlyModuleContext) (sdkVersion, error) {
-	if !s.valid() {
-		return s.version, fmt.Errorf("invalid sdk version %q", s.raw)
-	}
-
-	if ctx.DeviceSpecific() || ctx.SocSpecific() {
-		s = s.forVendorPartition(ctx)
-	}
-	if s.version.isNumbered() {
-		return s.version, nil
-	}
-	return sdkVersion(ctx.Config().DefaultAppTargetSdk(ctx).FinalOrFutureInt()), nil
-}
-
-// effectiveVersionString converts an sdkSpec into the concrete version string that the module
-// should use. For modules targeting an unreleased SDK (meaning it does not yet have a number)
-// it returns the codename (P, Q, R, etc.)
-func (s sdkSpec) effectiveVersionString(ctx android.EarlyModuleContext) (string, error) {
-	ver, err := s.effectiveVersion(ctx)
-	if err == nil && int(ver) == ctx.Config().DefaultAppTargetSdk(ctx).FinalOrFutureInt() {
-		return ctx.Config().DefaultAppTargetSdk(ctx).String(), nil
-	}
-	return ver.String(), err
-}
-
-func (s sdkSpec) defaultJavaLanguageVersion(ctx android.EarlyModuleContext) javaVersion {
-	sdk, err := s.effectiveVersion(ctx)
+func defaultJavaLanguageVersion(ctx android.EarlyModuleContext, s android.SdkSpec) javaVersion {
+	sdk, err := s.EffectiveVersion(ctx)
 	if err != nil {
 		ctx.PropertyErrorf("sdk_version", "%s", err)
 	}
@@ -275,103 +60,27 @@
 	}
 }
 
-func sdkSpecFrom(str string) sdkSpec {
-	switch str {
-	// special cases first
-	case "":
-		return sdkSpec{sdkPrivate, sdkVersionNone, str}
-	case "none":
-		return sdkSpec{sdkNone, sdkVersionNone, str}
-	case "core_platform":
-		return sdkSpec{sdkCorePlatform, sdkVersionNone, str}
-	default:
-		// the syntax is [kind_]version
-		sep := strings.LastIndex(str, "_")
-
-		var kindString string
-		if sep == 0 {
-			return sdkSpec{sdkInvalid, sdkVersionNone, str}
-		} else if sep == -1 {
-			kindString = ""
-		} else {
-			kindString = str[0:sep]
-		}
-		versionString := str[sep+1 : len(str)]
-
-		var kind sdkKind
-		switch kindString {
-		case "":
-			kind = sdkPublic
-		case "core":
-			kind = sdkCore
-		case "system":
-			kind = sdkSystem
-		case "test":
-			kind = sdkTest
-		case "module":
-			kind = sdkModule
-		case "system_server":
-			kind = sdkSystemServer
-		default:
-			return sdkSpec{sdkInvalid, sdkVersionNone, str}
-		}
-
-		var version sdkVersion
-		if versionString == "current" {
-			version = sdkVersionCurrent
-		} else if i, err := strconv.Atoi(versionString); err == nil {
-			version = sdkVersion(i)
-		} else {
-			return sdkSpec{sdkInvalid, sdkVersionNone, str}
-		}
-
-		return sdkSpec{kind, version, str}
-	}
-}
-
-func (s sdkSpec) validateSystemSdk(ctx android.EarlyModuleContext) bool {
-	// Ensures that the specified system SDK version is one of BOARD_SYSTEMSDK_VERSIONS (for vendor/product Java module)
-	// Assuming that BOARD_SYSTEMSDK_VERSIONS := 28 29,
-	// sdk_version of the modules in vendor/product that use system sdk must be either system_28, system_29 or system_current
-	if s.kind != sdkSystem || !s.version.isNumbered() {
-		return true
-	}
-	allowedVersions := ctx.DeviceConfig().PlatformSystemSdkVersions()
-	if ctx.DeviceSpecific() || ctx.SocSpecific() || (ctx.ProductSpecific() && ctx.Config().EnforceProductPartitionInterface()) {
-		systemSdkVersions := ctx.DeviceConfig().SystemSdkVersions()
-		if len(systemSdkVersions) > 0 {
-			allowedVersions = systemSdkVersions
-		}
-	}
-	if len(allowedVersions) > 0 && !android.InList(s.version.String(), allowedVersions) {
-		ctx.PropertyErrorf("sdk_version", "incompatible sdk version %q. System SDK version should be one of %q",
-			s.raw, allowedVersions)
-		return false
-	}
-	return true
-}
-
-func decodeSdkDep(ctx android.EarlyModuleContext, sdkContext sdkContext) sdkDep {
-	sdkVersion := sdkContext.sdkVersion()
-	if !sdkVersion.valid() {
-		ctx.PropertyErrorf("sdk_version", "invalid version %q", sdkVersion.raw)
+func decodeSdkDep(ctx android.EarlyModuleContext, sdkContext android.SdkContext) sdkDep {
+	sdkVersion := sdkContext.SdkVersion()
+	if !sdkVersion.Valid() {
+		ctx.PropertyErrorf("sdk_version", "invalid version %q", sdkVersion.Raw)
 		return sdkDep{}
 	}
 
 	if ctx.DeviceSpecific() || ctx.SocSpecific() {
-		sdkVersion = sdkVersion.forVendorPartition(ctx)
+		sdkVersion = sdkVersion.ForVendorPartition(ctx)
 	}
 
-	if !sdkVersion.validateSystemSdk(ctx) {
+	if !sdkVersion.ValidateSystemSdk(ctx) {
 		return sdkDep{}
 	}
 
-	if sdkVersion.usePrebuilt(ctx) {
-		dir := filepath.Join("prebuilts", "sdk", sdkVersion.version.String(), sdkVersion.kind.String())
+	if sdkVersion.UsePrebuilt(ctx) {
+		dir := filepath.Join("prebuilts", "sdk", sdkVersion.Version.String(), sdkVersion.Kind.String())
 		jar := filepath.Join(dir, "android.jar")
 		// There's no aidl for other SDKs yet.
 		// TODO(77525052): Add aidl files for other SDKs too.
-		publicDir := filepath.Join("prebuilts", "sdk", sdkVersion.version.String(), "public")
+		publicDir := filepath.Join("prebuilts", "sdk", sdkVersion.Version.String(), "public")
 		aidl := filepath.Join(publicDir, "framework.aidl")
 		jarPath := android.ExistentPathForSource(ctx, jar)
 		aidlPath := android.ExistentPathForSource(ctx, aidl)
@@ -380,23 +89,23 @@
 		if (!jarPath.Valid() || !aidlPath.Valid()) && ctx.Config().AllowMissingDependencies() {
 			return sdkDep{
 				invalidVersion: true,
-				bootclasspath:  []string{fmt.Sprintf("sdk_%s_%s_android", sdkVersion.kind, sdkVersion.version.String())},
+				bootclasspath:  []string{fmt.Sprintf("sdk_%s_%s_android", sdkVersion.Kind, sdkVersion.Version.String())},
 			}
 		}
 
 		if !jarPath.Valid() {
-			ctx.PropertyErrorf("sdk_version", "invalid sdk version %q, %q does not exist", sdkVersion.raw, jar)
+			ctx.PropertyErrorf("sdk_version", "invalid sdk version %q, %q does not exist", sdkVersion.Raw, jar)
 			return sdkDep{}
 		}
 
 		if !aidlPath.Valid() {
-			ctx.PropertyErrorf("sdk_version", "invalid sdk version %q, %q does not exist", sdkVersion.raw, aidl)
+			ctx.PropertyErrorf("sdk_version", "invalid sdk version %q, %q does not exist", sdkVersion.Raw, aidl)
 			return sdkDep{}
 		}
 
 		var systemModules string
-		if sdkVersion.defaultJavaLanguageVersion(ctx).usesJavaModules() {
-			systemModules = "sdk_public_" + sdkVersion.version.String() + "_system_modules"
+		if defaultJavaLanguageVersion(ctx, sdkVersion).usesJavaModules() {
+			systemModules = "sdk_public_" + sdkVersion.Version.String() + "_system_modules"
 		}
 
 		return sdkDep{
@@ -418,8 +127,8 @@
 		}
 	}
 
-	switch sdkVersion.kind {
-	case sdkPrivate:
+	switch sdkVersion.Kind {
+	case android.SdkPrivate:
 		return sdkDep{
 			useModule:          true,
 			systemModules:      corePlatformSystemModules(ctx),
@@ -427,8 +136,8 @@
 			classpath:          config.FrameworkLibraries,
 			frameworkResModule: "framework-res",
 		}
-	case sdkNone:
-		systemModules := sdkContext.systemModules()
+	case android.SdkNone:
+		systemModules := sdkContext.SystemModules()
 		if systemModules == "" {
 			ctx.PropertyErrorf("sdk_version",
 				`system_modules is required to be set to a non-empty value when sdk_version is "none", did you mean sdk_version: "core_platform"?`)
@@ -444,34 +153,34 @@
 			systemModules:  systemModules,
 			bootclasspath:  []string{systemModules},
 		}
-	case sdkCorePlatform:
+	case android.SdkCorePlatform:
 		return sdkDep{
 			useModule:        true,
 			systemModules:    corePlatformSystemModules(ctx),
 			bootclasspath:    corePlatformBootclasspathLibraries(ctx),
 			noFrameworksLibs: true,
 		}
-	case sdkPublic:
+	case android.SdkPublic:
 		return toModule([]string{"android_stubs_current"}, "framework-res", sdkFrameworkAidlPath(ctx))
-	case sdkSystem:
+	case android.SdkSystem:
 		return toModule([]string{"android_system_stubs_current"}, "framework-res", sdkFrameworkAidlPath(ctx))
-	case sdkTest:
+	case android.SdkTest:
 		return toModule([]string{"android_test_stubs_current"}, "framework-res", sdkFrameworkAidlPath(ctx))
-	case sdkCore:
+	case android.SdkCore:
 		return sdkDep{
 			useModule:        true,
 			bootclasspath:    []string{"core.current.stubs", config.DefaultLambdaStubsLibrary},
 			systemModules:    "core-current-stubs-system-modules",
 			noFrameworksLibs: true,
 		}
-	case sdkModule:
+	case android.SdkModule:
 		// TODO(146757305): provide .apk and .aidl that have more APIs for modules
 		return toModule([]string{"android_module_lib_stubs_current"}, "framework-res", nonUpdatableFrameworkAidlPath(ctx))
-	case sdkSystemServer:
+	case android.SdkSystemServer:
 		// TODO(146757305): provide .apk and .aidl that have more APIs for modules
 		return toModule([]string{"android_system_server_stubs_current"}, "framework-res", sdkFrameworkAidlPath(ctx))
 	default:
-		panic(fmt.Errorf("invalid sdk %q", sdkVersion.raw))
+		panic(fmt.Errorf("invalid sdk %q", sdkVersion.Raw))
 	}
 }
 
diff --git a/java/sdk_library.go b/java/sdk_library.go
index e1ca77d..ebb2154 100644
--- a/java/sdk_library.go
+++ b/java/sdk_library.go
@@ -814,22 +814,22 @@
 	return nil
 }
 
-func (c *commonToSdkLibraryAndImport) selectHeaderJarsForSdkVersion(ctx android.BaseModuleContext, sdkVersion sdkSpec) android.Paths {
+func (c *commonToSdkLibraryAndImport) selectHeaderJarsForSdkVersion(ctx android.BaseModuleContext, sdkVersion android.SdkSpec) android.Paths {
 
 	// If a specific numeric version has been requested then use prebuilt versions of the sdk.
-	if sdkVersion.version.isNumbered() {
+	if sdkVersion.Version.IsNumbered() {
 		return PrebuiltJars(ctx, c.moduleBase.BaseModuleName(), sdkVersion)
 	}
 
 	var apiScope *apiScope
-	switch sdkVersion.kind {
-	case sdkSystem:
+	switch sdkVersion.Kind {
+	case android.SdkSystem:
 		apiScope = apiScopeSystem
-	case sdkModule:
+	case android.SdkModule:
 		apiScope = apiScopeModuleLib
-	case sdkTest:
+	case android.SdkTest:
 		apiScope = apiScopeTest
-	case sdkSystemServer:
+	case android.SdkSystemServer:
 		apiScope = apiScopeSystemServer
 	default:
 		apiScope = apiScopePublic
@@ -932,14 +932,14 @@
 	//
 	// These are turbine generated jars so they only change if the externals of the
 	// class changes but it does not contain and implementation or JavaDoc.
-	SdkHeaderJars(ctx android.BaseModuleContext, sdkVersion sdkSpec) android.Paths
+	SdkHeaderJars(ctx android.BaseModuleContext, sdkVersion android.SdkSpec) android.Paths
 
 	// Get the implementation jars appropriate for the supplied sdk version.
 	//
 	// These are either the implementation jar for the whole sdk library or the implementation
 	// jars for the stubs. The latter should only be needed when generating JavaDoc as otherwise
 	// they are identical to the corresponding header jars.
-	SdkImplementationJars(ctx android.BaseModuleContext, sdkVersion sdkSpec) android.Paths
+	SdkImplementationJars(ctx android.BaseModuleContext, sdkVersion android.SdkSpec) android.Paths
 }
 
 type SdkLibrary struct {
@@ -1147,7 +1147,7 @@
 		return proptools.String(scopeProperties.Sdk_version)
 	}
 
-	sdkDep := decodeSdkDep(mctx, sdkContext(&module.Library))
+	sdkDep := decodeSdkDep(mctx, android.SdkContext(&module.Library))
 	if sdkDep.hasStandardLibs() {
 		// If building against a standard sdk then use the sdk version appropriate for the scope.
 		return apiScope.sdkVersion
@@ -1465,17 +1465,17 @@
 	mctx.CreateModule(sdkLibraryXmlFactory, &props)
 }
 
-func PrebuiltJars(ctx android.BaseModuleContext, baseName string, s sdkSpec) android.Paths {
-	var ver sdkVersion
-	var kind sdkKind
-	if s.usePrebuilt(ctx) {
-		ver = s.version
-		kind = s.kind
+func PrebuiltJars(ctx android.BaseModuleContext, baseName string, s android.SdkSpec) android.Paths {
+	var ver android.SdkVersion
+	var kind android.SdkKind
+	if s.UsePrebuilt(ctx) {
+		ver = s.Version
+		kind = s.Kind
 	} else {
 		// We don't have prebuilt SDK for the specific sdkVersion.
 		// Instead of breaking the build, fallback to use "system_current"
-		ver = sdkVersionCurrent
-		kind = sdkSystem
+		ver = android.SdkVersionCurrent
+		kind = android.SdkSystem
 	}
 
 	dir := filepath.Join("prebuilts", "sdk", ver.String(), kind.String())
@@ -1485,7 +1485,7 @@
 		if ctx.Config().AllowMissingDependencies() {
 			return android.Paths{android.PathForSource(ctx, jar)}
 		} else {
-			ctx.PropertyErrorf("sdk_library", "invalid sdk version %q, %q does not exist", s.raw, jar)
+			ctx.PropertyErrorf("sdk_library", "invalid sdk version %q, %q does not exist", s.Raw, jar)
 		}
 		return nil
 	}
@@ -1502,13 +1502,13 @@
 	return len(otherApexInfo.InApexes) > 0 && reflect.DeepEqual(apexInfo.InApexes, otherApexInfo.InApexes)
 }
 
-func (module *SdkLibrary) sdkJars(ctx android.BaseModuleContext, sdkVersion sdkSpec, headerJars bool) android.Paths {
+func (module *SdkLibrary) sdkJars(ctx android.BaseModuleContext, sdkVersion android.SdkSpec, headerJars bool) android.Paths {
 	// If the client doesn't set sdk_version, but if this library prefers stubs over
 	// the impl library, let's provide the widest API surface possible. To do so,
 	// force override sdk_version to module_current so that the closest possible API
 	// surface could be found in selectHeaderJarsForSdkVersion
-	if module.defaultsToStubs() && !sdkVersion.specified() {
-		sdkVersion = sdkSpecFrom("module_current")
+	if module.defaultsToStubs() && !sdkVersion.Specified() {
+		sdkVersion = android.SdkSpecFrom("module_current")
 	}
 
 	// Only provide access to the implementation library if it is actually built.
@@ -1518,7 +1518,7 @@
 		// Only allow access to the implementation library in the following condition:
 		// * No sdk_version specified on the referencing module.
 		// * The referencing module is in the same apex as this.
-		if sdkVersion.kind == sdkPrivate || withinSameApexesAs(ctx, module) {
+		if sdkVersion.Kind == android.SdkPrivate || withinSameApexesAs(ctx, module) {
 			if headerJars {
 				return module.HeaderJars()
 			} else {
@@ -1531,12 +1531,12 @@
 }
 
 // to satisfy SdkLibraryDependency interface
-func (module *SdkLibrary) SdkHeaderJars(ctx android.BaseModuleContext, sdkVersion sdkSpec) android.Paths {
+func (module *SdkLibrary) SdkHeaderJars(ctx android.BaseModuleContext, sdkVersion android.SdkSpec) android.Paths {
 	return module.sdkJars(ctx, sdkVersion, true /*headerJars*/)
 }
 
 // to satisfy SdkLibraryDependency interface
-func (module *SdkLibrary) SdkImplementationJars(ctx android.BaseModuleContext, sdkVersion sdkSpec) android.Paths {
+func (module *SdkLibrary) SdkImplementationJars(ctx android.BaseModuleContext, sdkVersion android.SdkSpec) android.Paths {
 	return module.sdkJars(ctx, sdkVersion, false /*headerJars*/)
 }
 
@@ -1568,7 +1568,7 @@
 
 	// If this builds against standard libraries (i.e. is not part of the core libraries)
 	// then assume it provides both system and test apis.
-	sdkDep := decodeSdkDep(mctx, sdkContext(&module.Library))
+	sdkDep := decodeSdkDep(mctx, android.SdkContext(&module.Library))
 	hasSystemAndTestApis := sdkDep.hasStandardLibs()
 	module.sdkLibraryProperties.Generate_system_and_test_apis = hasSystemAndTestApis
 
@@ -2069,7 +2069,7 @@
 	}
 }
 
-func (module *SdkLibraryImport) sdkJars(ctx android.BaseModuleContext, sdkVersion sdkSpec, headerJars bool) android.Paths {
+func (module *SdkLibraryImport) sdkJars(ctx android.BaseModuleContext, sdkVersion android.SdkSpec, headerJars bool) android.Paths {
 
 	// For consistency with SdkLibrary make the implementation jar available to libraries that
 	// are within the same APEX.
@@ -2086,13 +2086,13 @@
 }
 
 // to satisfy SdkLibraryDependency interface
-func (module *SdkLibraryImport) SdkHeaderJars(ctx android.BaseModuleContext, sdkVersion sdkSpec) android.Paths {
+func (module *SdkLibraryImport) SdkHeaderJars(ctx android.BaseModuleContext, sdkVersion android.SdkSpec) android.Paths {
 	// This module is just a wrapper for the prebuilt stubs.
 	return module.sdkJars(ctx, sdkVersion, true)
 }
 
 // to satisfy SdkLibraryDependency interface
-func (module *SdkLibraryImport) SdkImplementationJars(ctx android.BaseModuleContext, sdkVersion sdkSpec) android.Paths {
+func (module *SdkLibraryImport) SdkImplementationJars(ctx android.BaseModuleContext, sdkVersion android.SdkSpec) android.Paths {
 	// This module is just a wrapper for the stubs.
 	return module.sdkJars(ctx, sdkVersion, false)
 }
diff --git a/sysprop/sysprop_test.go b/sysprop/sysprop_test.go
index e9d9051..f42f9e9 100644
--- a/sysprop/sysprop_test.go
+++ b/sysprop/sysprop_test.go
@@ -371,6 +371,6 @@
 	android.AssertStringEquals(t, "min_sdk_version forwarding to cc module", "29", propFromCc)
 
 	javaModule := result.ModuleForTests("sysprop-platform", "android_common").Module().(*java.Library)
-	propFromJava := javaModule.MinSdkVersion()
+	propFromJava := javaModule.MinSdkVersionString()
 	android.AssertStringEquals(t, "min_sdk_version forwarding to java module", "30", propFromJava)
 }