diff --git a/ortools/init/BUILD.bazel b/ortools/init/BUILD.bazel
index efe615cddb4..95b55c918cf 100644
--- a/ortools/init/BUILD.bazel
+++ b/ortools/init/BUILD.bazel
@@ -16,10 +16,12 @@ package(default_visibility = ["//visibility:public"])
 cc_library(
     name = "init",
     hdrs = ["init.h"],
+    srcs = ["init.cc"],
     deps = [
         "//ortools/base",
         "//ortools/gurobi:environment",
         "//ortools/sat:cp_model_solver",
+        "//ortools/sat:cp_model_solver_helpers",
         "@com_google_absl//absl/flags:flag",
         "@com_google_absl//absl/log",
         "@com_google_absl//absl/log:globals",
diff --git a/ortools/init/CMakeLists.txt b/ortools/init/CMakeLists.txt
index f5fbec03c0f..25f6fa98dc5 100644
--- a/ortools/init/CMakeLists.txt
+++ b/ortools/init/CMakeLists.txt
@@ -11,7 +11,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-file(GLOB _SRCS "*.h")
+file(GLOB _SRCS "*.h" "*.cc")
 set(NAME ${PROJECT_NAME}_init)
 
 # Will be merge in libortools.so
diff --git a/ortools/init/init.cc b/ortools/init/init.cc
new file mode 100644
index 00000000000..c02a33f7099
--- /dev/null
+++ b/ortools/init/init.cc
@@ -0,0 +1,46 @@
+// Copyright 2010-2025 Google LLC
+// 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.
+
+#include "ortools/init/init.h"
+
+#include "absl/flags/flag.h"
+#include "absl/flags/usage.h"
+#include "absl/log/globals.h"
+#include "absl/log/initialize.h"
+#include "ortools/gurobi/environment.h"
+#include "ortools/sat/cp_model_solver.h"
+#include "ortools/sat/cp_model_solver_helpers.h"
+
+namespace operations_research {
+  void CppBridge::InitLogging(const std::string& usage) {
+    absl::SetProgramUsageMessage(usage);
+    absl::InitializeLog();
+  }
+
+  void CppBridge::SetFlags(const CppFlags& flags) {
+    absl::SetFlag(&FLAGS_stderrthreshold, flags.stderrthreshold);
+    absl::EnableLogPrefix(flags.log_prefix);
+    if (!flags.cp_model_dump_prefix.empty()) {
+      absl::SetFlag(&FLAGS_cp_model_dump_prefix, flags.cp_model_dump_prefix);
+    }
+    absl::SetFlag(&FLAGS_cp_model_dump_models, flags.cp_model_dump_models);
+    absl::SetFlag(&FLAGS_cp_model_dump_submodels,
+        flags.cp_model_dump_submodels);
+    absl::SetFlag(&FLAGS_cp_model_dump_response, flags.cp_model_dump_response);
+  }
+
+  bool CppBridge::LoadGurobiSharedLibrary(const std::string& full_library_path) {
+    return LoadGurobiDynamicLibrary({full_library_path}).ok();
+  }
+
+}  // namespace operations_research
diff --git a/ortools/init/init.h b/ortools/init/init.h
index 76e182f3bc6..142ecd449e3 100644
--- a/ortools/init/init.h
+++ b/ortools/init/init.h
@@ -18,20 +18,9 @@
 #include <string>
 #include <vector>
 
-#include "absl/flags/flag.h"
-#include "absl/flags/usage.h"
-#include "absl/log/globals.h"
-#include "absl/log/initialize.h"
 #include "ortools/base/logging.h"
 #include "ortools/base/version.h"
-#include "ortools/gurobi/environment.h"
-#include "ortools/sat/cp_model_solver.h"
-
-ABSL_DECLARE_FLAG(std::string, cp_model_dump_prefix);
-ABSL_DECLARE_FLAG(bool, cp_model_dump_models);
-ABSL_DECLARE_FLAG(bool, cp_model_dump_submodels);
-ABSL_DECLARE_FLAG(bool, cp_model_dump_response);
-ABSL_DECLARE_FLAG(int, stderrthreshold);
+#include "ortools/sat/cp_model_solver_helpers.h"
 
 namespace operations_research {
 
@@ -97,10 +86,7 @@ class CppBridge {
    *
    * This must be called once before any other library from OR-Tools are used.
    */
-  static void InitLogging(const std::string& usage) {
-    absl::SetProgramUsageMessage(usage);
-    absl::InitializeLog();
-  }
+  static void InitLogging(const std::string& usage);
 
   /**
    * Shutdown the C++ logging layer.
@@ -115,17 +101,7 @@ class CppBridge {
   /**
    * Sets all the C++ flags contained in the CppFlags structure.
    */
-  static void SetFlags(const CppFlags& flags) {
-    absl::SetFlag(&FLAGS_stderrthreshold, flags.stderrthreshold);
-    absl::EnableLogPrefix(flags.log_prefix);
-    if (!flags.cp_model_dump_prefix.empty()) {
-      absl::SetFlag(&FLAGS_cp_model_dump_prefix, flags.cp_model_dump_prefix);
-    }
-    absl::SetFlag(&FLAGS_cp_model_dump_models, flags.cp_model_dump_models);
-    absl::SetFlag(&FLAGS_cp_model_dump_submodels,
-                  flags.cp_model_dump_submodels);
-    absl::SetFlag(&FLAGS_cp_model_dump_response, flags.cp_model_dump_response);
-  }
+  static void SetFlags(const CppFlags& flags);
 
   /**
    * Load the gurobi shared library.
@@ -135,9 +111,7 @@ class CppBridge {
    * You need to pass the full path, including the shared library file.
    * It returns true if the library was found and correctly loaded.
    */
-  static bool LoadGurobiSharedLibrary(const std::string& full_library_path) {
-    return LoadGurobiDynamicLibrary({full_library_path}).ok();
-  }
+  static bool LoadGurobiSharedLibrary(const std::string& full_library_path);
 
   /**
    * Delete a temporary C++ byte array.
diff --git a/ortools/sat/cp_model_solver.h b/ortools/sat/cp_model_solver.h
index 3bec9b5278e..90ef155a70d 100644
--- a/ortools/sat/cp_model_solver.h
+++ b/ortools/sat/cp_model_solver.h
@@ -21,6 +21,8 @@
 #include "ortools/sat/model.h"
 #include "ortools/sat/sat_parameters.pb.h"
 
+ABSL_DECLARE_FLAG(bool, cp_model_dump_response);
+
 namespace operations_research {
 namespace sat {