diff --git a/BUILD.gn b/BUILD.gn
new file mode 100644
index 000000000..02867ab4e
--- /dev/null
+++ b/BUILD.gn
@@ -0,0 +1,20 @@
+# Part of the Crubit project, under the Apache License v2.0 with LLVM
+# Exceptions. See /LICENSE for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+import("crubit.gni")
+
+group("cpp_api_from_rust_bindings_rs_deps") {
+  # These are the dependencies required by Rust implementations of bindings.
+  public_deps = [
+  ]
+}
+
+group("cpp_api_from_rust_bindings_cpp_deps") {
+  # These are the dependencies required by C++ implementations of bindings.
+  public_deps = [
+    "$crubit_src_dir/support",
+    "$crubit_src_dir/support/rs_std",
+    "$crubit_src_dir/support/internal",
+  ]
+}
diff --git a/crubit.gni b/crubit.gni
new file mode 100644
index 000000000..601fec144
--- /dev/null
+++ b/crubit.gni
@@ -0,0 +1,13 @@
+# Part of the Crubit project, under the Apache License v2.0 with LLVM
+# Exceptions. See /LICENSE for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+import("//build_overrides/crubit.gni")
+
+if (!defined(crubit_src_dir)) {
+  crubit_src_dir = "//third_party/crubit"
+}
+
+if (!defined(crubit_absl_dep_target)) {
+  crubit_absl_dep_target = "//third_party/abseil-cpp:absl"
+}
diff --git a/support/BUILD b/support/BUILD
index e36e82842..2f41f7fc5 100644
--- a/support/BUILD
+++ b/support/BUILD
@@ -295,8 +295,9 @@ filegroup(
 )
 
 bazel_to_builds(
-    name = "generate_cmake",
+    name = "generate_builds",
     cmake = "CMakeLists.txt",
+    gn = "BUILD.gn",
     targets = [
         ":annotations",
         ":annotations_internal",
diff --git a/support/BUILD.gn b/support/BUILD.gn
new file mode 100644
index 000000000..d12a64241
--- /dev/null
+++ b/support/BUILD.gn
@@ -0,0 +1,80 @@
+# Part of the Crubit project, under the Apache License v2.0 with LLVM
+# Exceptions. See /LICENSE for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+# Automatically @generated BUILD.gn.
+
+import("../crubit.gni")
+
+visibility = [ "$crubit_src_dir/*" ]
+
+source_set("annotations") {
+  public_configs = [ "$crubit_src_dir/support:config" ]
+  if (defined(crubit_gn_configs_to_remove)) {
+    configs -= crubit_gn_configs_to_remove
+  }
+  if (defined(crubit_gn_support_configs_to_add)) {
+    configs += crubit_gn_support_configs_to_add
+  }
+
+  public = [
+    "annotations.h",
+  ]
+  deps = [
+    "$crubit_src_dir/support:annotations_internal",
+  ]
+}
+
+source_set("annotations_internal") {
+  public_configs = [ "$crubit_src_dir/support:config" ]
+  if (defined(crubit_gn_configs_to_remove)) {
+    configs -= crubit_gn_configs_to_remove
+  }
+  if (defined(crubit_gn_support_configs_to_add)) {
+    configs += crubit_gn_support_configs_to_add
+  }
+
+  public = [
+    "annotations_internal.h",
+  ]
+  deps = [
+    "$crubit_absl_dep_target",
+  ]
+}
+
+source_set("bridge_cpp") {
+  public_configs = [ "$crubit_src_dir/support:config" ]
+  if (defined(crubit_gn_configs_to_remove)) {
+    configs -= crubit_gn_configs_to_remove
+  }
+  if (defined(crubit_gn_support_configs_to_add)) {
+    configs += crubit_gn_support_configs_to_add
+  }
+
+  public = [
+    "bridge.h",
+  ]
+}
+
+source_set("lifetime_annotations") {
+  public_configs = [ "$crubit_src_dir/support:config" ]
+  if (defined(crubit_gn_configs_to_remove)) {
+    configs -= crubit_gn_configs_to_remove
+  }
+  if (defined(crubit_gn_support_configs_to_add)) {
+    configs += crubit_gn_support_configs_to_add
+  }
+
+  public = [
+    "lifetime_annotations.h",
+  ]
+}
+
+group("support") {
+  public_deps = [
+    ":annotations",
+    ":annotations_internal",
+    ":bridge_cpp",
+    ":lifetime_annotations",
+  ]
+}
diff --git a/support/internal/BUILD b/support/internal/BUILD
index a1eaf91e9..f776dc0e1 100644
--- a/support/internal/BUILD
+++ b/support/internal/BUILD
@@ -86,8 +86,9 @@ crubit_cc_test(
 )
 
 bazel_to_builds(
-    name = "generate_cmake",
+    name = "generate_builds",
     cmake = "CMakeLists.txt",
+    gn = "BUILD.gn",
     targets = [
         ":bindings_support",
     ],
diff --git a/support/internal/BUILD.gn b/support/internal/BUILD.gn
new file mode 100644
index 000000000..9850eddd3
--- /dev/null
+++ b/support/internal/BUILD.gn
@@ -0,0 +1,43 @@
+# Part of the Crubit project, under the Apache License v2.0 with LLVM
+# Exceptions. See /LICENSE for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+# Automatically @generated BUILD.gn.
+
+import("../../crubit.gni")
+
+visibility = [ "$crubit_src_dir/*" ]
+
+source_set("bindings_support") {
+  public_configs = [ "$crubit_src_dir/support:config" ]
+  if (defined(crubit_gn_configs_to_remove)) {
+    configs -= crubit_gn_configs_to_remove
+  }
+  if (defined(crubit_gn_support_configs_to_add)) {
+    configs += crubit_gn_support_configs_to_add
+  }
+
+  public = [
+    "check.h",
+    "check_no_mutable_aliasing.h",
+    "cxx20_backports.h",
+    "fmt.h",
+    "lazy_init.h",
+    "memswap.h",
+    "offsetof.h",
+    "sizeof.h",
+    "slot.h",
+  ]
+  sources = [
+    "check_no_mutable_aliasing.cc",
+  ]
+  deps = [
+    "$crubit_absl_dep_target",
+  ]
+}
+
+group("internal") {
+  public_deps = [
+    ":bindings_support",
+  ]
+}
diff --git a/support/rs_std/BUILD b/support/rs_std/BUILD
index cd1df3982..c089e904a 100644
--- a/support/rs_std/BUILD
+++ b/support/rs_std/BUILD
@@ -279,8 +279,9 @@ cpp_api_from_rust_toolchain_bindings(
 )
 
 bazel_to_builds(
-    name = "generate_cmake",
+    name = "generate_builds",
     cmake = "CMakeLists.txt",
+    gn = "BUILD.gn",
     targets = [
         ":char",
         ":slice_ref",
diff --git a/support/rs_std/BUILD.gn b/support/rs_std/BUILD.gn
new file mode 100644
index 000000000..3960cc407
--- /dev/null
+++ b/support/rs_std/BUILD.gn
@@ -0,0 +1,161 @@
+# Part of the Crubit project, under the Apache License v2.0 with LLVM
+# Exceptions. See /LICENSE for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+# Automatically @generated BUILD.gn.
+
+import("../../crubit.gni")
+
+visibility = [ "$crubit_src_dir/*" ]
+
+source_set("char") {
+  public_configs = [ "$crubit_src_dir/support:config" ]
+  if (defined(crubit_gn_configs_to_remove)) {
+    configs -= crubit_gn_configs_to_remove
+  }
+  if (defined(crubit_gn_support_configs_to_add)) {
+    configs += crubit_gn_support_configs_to_add
+  }
+
+  public = [
+    "char.h",
+  ]
+  sources = [
+    "char.cc",
+  ]
+  deps = [
+    "$crubit_src_dir/support/rs_std:str_ref",
+    "$crubit_src_dir/support:annotations",
+    "$crubit_absl_dep_target",
+  ]
+}
+
+source_set("slice_ref") {
+  public_configs = [ "$crubit_src_dir/support:config" ]
+  if (defined(crubit_gn_configs_to_remove)) {
+    configs -= crubit_gn_configs_to_remove
+  }
+  if (defined(crubit_gn_support_configs_to_add)) {
+    configs += crubit_gn_support_configs_to_add
+  }
+
+  public = [
+    "slice_ref.h",
+  ]
+  deps = [
+    "$crubit_src_dir/support:annotations_internal",
+    "$crubit_src_dir/support/internal:bindings_support",
+    "$crubit_absl_dep_target",
+  ]
+}
+
+source_set("str_ref") {
+  public_configs = [ "$crubit_src_dir/support:config" ]
+  if (defined(crubit_gn_configs_to_remove)) {
+    configs -= crubit_gn_configs_to_remove
+  }
+  if (defined(crubit_gn_support_configs_to_add)) {
+    configs += crubit_gn_support_configs_to_add
+  }
+
+  public = [
+    "str_ref.h",
+  ]
+  deps = [
+    "$crubit_src_dir/support/rs_std:slice_ref",
+    "$crubit_src_dir/support:annotations_internal",
+    "$crubit_src_dir/support/internal:bindings_support",
+    "$crubit_src_dir/support/rs_std/internal:is_utf8",
+    "$crubit_absl_dep_target",
+  ]
+}
+
+source_set("dyn_callable") {
+  public_configs = [ "$crubit_src_dir/support:config" ]
+  if (defined(crubit_gn_configs_to_remove)) {
+    configs -= crubit_gn_configs_to_remove
+  }
+  if (defined(crubit_gn_support_configs_to_add)) {
+    configs += crubit_gn_support_configs_to_add
+  }
+
+  public = [
+    "dyn_callable.h",
+  ]
+  deps = [
+    "$crubit_src_dir/support:bridge_cpp",
+    "$crubit_absl_dep_target",
+  ]
+}
+
+source_set("traits") {
+  public_configs = [ "$crubit_src_dir/support:config" ]
+  if (defined(crubit_gn_configs_to_remove)) {
+    configs -= crubit_gn_configs_to_remove
+  }
+  if (defined(crubit_gn_support_configs_to_add)) {
+    configs += crubit_gn_support_configs_to_add
+  }
+
+  public = [
+    "traits.h",
+  ]
+}
+
+source_set("option") {
+  public_configs = [ "$crubit_src_dir/support:config" ]
+  if (defined(crubit_gn_configs_to_remove)) {
+    configs -= crubit_gn_configs_to_remove
+  }
+  if (defined(crubit_gn_support_configs_to_add)) {
+    configs += crubit_gn_support_configs_to_add
+  }
+
+  public = [
+    "option.h",
+  ]
+}
+
+source_set("result") {
+  public_configs = [ "$crubit_src_dir/support:config" ]
+  if (defined(crubit_gn_configs_to_remove)) {
+    configs -= crubit_gn_configs_to_remove
+  }
+  if (defined(crubit_gn_support_configs_to_add)) {
+    configs += crubit_gn_support_configs_to_add
+  }
+
+  public = [
+    "result.h",
+  ]
+}
+
+source_set("lossy_formatter_for_bindings") {
+  public_configs = [ "$crubit_src_dir/support:config" ]
+  if (defined(crubit_gn_configs_to_remove)) {
+    configs -= crubit_gn_configs_to_remove
+  }
+  if (defined(crubit_gn_support_configs_to_add)) {
+    configs += crubit_gn_support_configs_to_add
+  }
+
+  public = [
+    "lossy_formatter_for_bindings.h",
+  ]
+  deps = [
+    "$crubit_src_dir/support/rs_std:lossy_formatter_cc",
+  ]
+}
+
+group("rs_std") {
+  public_deps = [
+    ":char",
+    ":slice_ref",
+    ":str_ref",
+    ":dyn_callable",
+    ":traits",
+    ":option",
+    ":result",
+    ":lossy_formatter_for_bindings",
+  ]
+}
diff --git a/support/rs_std/internal/BUILD b/support/rs_std/internal/BUILD
index b37d60553..57a165aed 100644
--- a/support/rs_std/internal/BUILD
+++ b/support/rs_std/internal/BUILD
@@ -34,8 +34,9 @@ cc_test(
 )
 
 bazel_to_builds(
-    name = "generate_cmake",
+    name = "generate_builds",
     cmake = "CMakeLists.txt",
+    gn = "BUILD.gn",
     targets = [
         ":is_utf8",
     ],
diff --git a/support/rs_std/internal/BUILD.gn b/support/rs_std/internal/BUILD.gn
new file mode 100644
index 000000000..1745d1f51
--- /dev/null
+++ b/support/rs_std/internal/BUILD.gn
@@ -0,0 +1,32 @@
+# Part of the Crubit project, under the Apache License v2.0 with LLVM
+# Exceptions. See /LICENSE for license information.
+# SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+# Automatically @generated BUILD.gn.
+
+import("../../../crubit.gni")
+
+visibility = [ "$crubit_src_dir/*" ]
+
+source_set("is_utf8") {
+  public_configs = [ "$crubit_src_dir/support:config" ]
+  if (defined(crubit_gn_configs_to_remove)) {
+    configs -= crubit_gn_configs_to_remove
+  }
+  if (defined(crubit_gn_support_configs_to_add)) {
+    configs += crubit_gn_support_configs_to_add
+  }
+
+  public = [
+    "is_utf8.h",
+  ]
+  deps = [
+    "$crubit_absl_dep_target",
+  ]
+}
+
+group("internal") {
+  public_deps = [
+    ":is_utf8",
+  ]
+}