diff --git a/aconfig/build_flags/init.go b/aconfig/build_flags/init.go
new file mode 100644
index 0000000..5907f4e
--- /dev/null
+++ b/aconfig/build_flags/init.go
@@ -0,0 +1,78 @@
+// Copyright 2023 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 build_flags
+
+import (
+	"android/soong/android"
+
+	"github.com/google/blueprint"
+)
+
+var (
+	pctx = android.NewPackageContext("android/soong/aconfig/build_flags")
+
+	// For build_flag_declarations: Generate cache file
+	buildFlagRule = pctx.AndroidStaticRule("build-flag-declarations",
+		blueprint.RuleParams{
+			Command: `${buildFlagDeclarations} ` +
+				` ${declarations}` +
+				` --format pb` +
+				` --output ${out}.tmp` +
+				` && ( if cmp -s ${out}.tmp ${out} ; then rm ${out}.tmp ; else mv ${out}.tmp ${out} ; fi )`,
+			CommandDeps: []string{
+				"${buildFlagDeclarations}",
+			},
+			Restat: true,
+		}, "release_version", "declarations")
+
+	buildFlagTextRule = pctx.AndroidStaticRule("build-flag-declarations-text",
+		blueprint.RuleParams{
+			Command: `${buildFlagDeclarations} --format=textproto` +
+				` --intermediate ${in}` +
+				` --format textproto` +
+				` --output ${out}.tmp` +
+				` && ( if cmp -s ${out}.tmp ${out} ; then rm ${out}.tmp ; else mv ${out}.tmp ${out} ; fi )`,
+			CommandDeps: []string{
+				"${buildFlagDeclarations}",
+			},
+			Restat: true,
+		})
+
+	allDeclarationsRule = pctx.AndroidStaticRule("all-build-flag-declarations-dump",
+		blueprint.RuleParams{
+			Command: `${buildFlagDeclarations} ${intermediates} --format pb --output ${out}`,
+			CommandDeps: []string{
+				"${buildFlagDeclarations}",
+			},
+		}, "intermediates")
+
+	allDeclarationsRuleTextProto = pctx.AndroidStaticRule("All_build_flag_declarations_dump_textproto",
+		blueprint.RuleParams{
+			Command: `${buildFlagDeclarations} --intermediate ${in} --format textproto --output ${out}`,
+			CommandDeps: []string{
+				"${buildFlagDeclarations}",
+			},
+		})
+)
+
+func init() {
+	RegisterBuildComponents(android.InitRegistrationContext)
+	pctx.HostBinToolVariable("buildFlagDeclarations", "build-flag-declarations")
+}
+
+func RegisterBuildComponents(ctx android.RegistrationContext) {
+	ctx.RegisterModuleType("build_flag_declarations", DeclarationsFactory)
+	ctx.RegisterParallelSingletonType("all_build_flag_declarations", AllBuildFlagDeclarationsFactory)
+}