Unless otherwise configured, the client libraries useApplication Default Credentialsto authenticate with Google Cloud Services. While this works for most applications, in some cases you may need to override this default. You can do so by providing theUnifiedCredentialsOptionThe following example shows how to explicitly load a service account key file:
[](std::string const& keyfile) {
auto is = std::ifstream(keyfile);
is.exceptions(std::ios::badbit); // Minimal error handling in examples
auto contents = std::string(std::istreambuf_iterator<char>(is.rdbuf()), {});
auto options =
google::cloud::Options{}.set<google::cloud::UnifiedCredentialsOption>(
google::cloud::MakeServiceAccountCredentials(contents));
return google::cloud::cloudbuild_v1::CloudBuildClient(
google::cloud::cloudbuild_v1::MakeCloudBuildConnection(options));
}
Follow these links to find examples for other*Clientclasses:
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-09-04 UTC."],[[["\u003cp\u003eThis page provides documentation for various versions of the Google Cloud Build C++ client library, ranging from version 2.11.0 to the latest release candidate 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003eThe client libraries use Application Default Credentials for authentication by default, but it can be overridden using \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e to specify credentials like a service account key file.\u003c/p\u003e\n"],["\u003cp\u003eThe code example demonstrates how to load a service account key file to create \u003ccode\u003egoogle::cloud::UnifiedCredentialsOption\u003c/code\u003e, which is then used to establish a \u003ccode\u003eCloudBuildClient\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eExamples for overriding authentication are also available for \u003ccode\u003ecloudbuild_v1::CloudBuildClient\u003c/code\u003e and \u003ccode\u003ecloudbuild_v2::RepositoryManagerClient\u003c/code\u003e, within version 2.33.0 of the client library documentation.\u003c/p\u003e\n"],["\u003cp\u003eFor detailed information on creating \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects and managing service account keys, users are advised to refer to the "Authentication Components" documentation and the best practices guide.\u003c/p\u003e\n"]]],[],null,["Version 2.33.0keyboard_arrow_down\n\n- [2.42.0-rc (latest)](/cpp/docs/reference/cloudbuild/latest/cloudbuild-override-authentication)\n- [2.41.0](/cpp/docs/reference/cloudbuild/2.41.0/cloudbuild-override-authentication)\n- [2.40.0](/cpp/docs/reference/cloudbuild/2.40.0/cloudbuild-override-authentication)\n- [2.39.0](/cpp/docs/reference/cloudbuild/2.39.0/cloudbuild-override-authentication)\n- [2.38.0](/cpp/docs/reference/cloudbuild/2.38.0/cloudbuild-override-authentication)\n- [2.37.0](/cpp/docs/reference/cloudbuild/2.37.0/cloudbuild-override-authentication)\n- [2.36.0](/cpp/docs/reference/cloudbuild/2.36.0/cloudbuild-override-authentication)\n- [2.35.0](/cpp/docs/reference/cloudbuild/2.35.0/cloudbuild-override-authentication)\n- [2.34.0](/cpp/docs/reference/cloudbuild/2.34.0/cloudbuild-override-authentication)\n- [2.33.0](/cpp/docs/reference/cloudbuild/2.33.0/cloudbuild-override-authentication)\n- [2.32.0](/cpp/docs/reference/cloudbuild/2.32.0/cloudbuild-override-authentication)\n- [2.31.0](/cpp/docs/reference/cloudbuild/2.31.0/cloudbuild-override-authentication)\n- [2.30.0](/cpp/docs/reference/cloudbuild/2.30.0/cloudbuild-override-authentication)\n- [2.29.0](/cpp/docs/reference/cloudbuild/2.29.0/cloudbuild-override-authentication)\n- [2.28.0](/cpp/docs/reference/cloudbuild/2.28.0/cloudbuild-override-authentication)\n- [2.27.0](/cpp/docs/reference/cloudbuild/2.27.0/cloudbuild-override-authentication)\n- [2.26.0](/cpp/docs/reference/cloudbuild/2.26.0/cloudbuild-override-authentication)\n- [2.25.1](/cpp/docs/reference/cloudbuild/2.25.1/cloudbuild-override-authentication)\n- [2.24.0](/cpp/docs/reference/cloudbuild/2.24.0/cloudbuild-override-authentication)\n- [2.23.0](/cpp/docs/reference/cloudbuild/2.23.0/cloudbuild-override-authentication)\n- [2.22.1](/cpp/docs/reference/cloudbuild/2.22.1/cloudbuild-override-authentication)\n- [2.21.0](/cpp/docs/reference/cloudbuild/2.21.0/cloudbuild-override-authentication)\n- [2.20.0](/cpp/docs/reference/cloudbuild/2.20.0/cloudbuild-override-authentication)\n- [2.19.0](/cpp/docs/reference/cloudbuild/2.19.0/cloudbuild-override-authentication)\n- [2.18.0](/cpp/docs/reference/cloudbuild/2.18.0/cloudbuild-override-authentication)\n- [2.17.0](/cpp/docs/reference/cloudbuild/2.17.0/cloudbuild-override-authentication)\n- [2.16.0](/cpp/docs/reference/cloudbuild/2.16.0/cloudbuild-override-authentication)\n- [2.15.1](/cpp/docs/reference/cloudbuild/2.15.1/cloudbuild-override-authentication)\n- [2.14.0](/cpp/docs/reference/cloudbuild/2.14.0/cloudbuild-override-authentication)\n- [2.13.0](/cpp/docs/reference/cloudbuild/2.13.0/cloudbuild-override-authentication)\n- [2.12.0](/cpp/docs/reference/cloudbuild/2.12.0/cloudbuild-override-authentication)\n- [2.11.0](/cpp/docs/reference/cloudbuild/2.11.0/cloudbuild-override-authentication) \n\nHow to Override the Authentication Credentials\n==============================================\n\nUnless otherwise configured, the client libraries use [Application Default Credentials](https://cloud.google.com/docs/authentication#adc) to authenticate with Google Cloud Services. While this works for most applications, in some cases you may need to override this default. You can do so by providing the [UnifiedCredentialsOption](https://cloud.google.com/cpp/docs/reference/common/latest/structgoogle_1_1cloud_1_1UnifiedCredentialsOption.html) The following example shows how to explicitly load a service account key file: \n\n [](std::string const& keyfile) {\n auto is = std::ifstream(keyfile);\n is.exceptions(std::ios::badbit); // Minimal error handling in examples\n auto contents = std::string(std::istreambuf_iterator\u003cchar\u003e(is.rdbuf()), {});\n auto options =\n google::cloud::Options{}.set\u003cgoogle::cloud::UnifiedCredentialsOption\u003e(\n google::cloud::MakeServiceAccountCredentials(contents));\n return google::cloud::cloudbuild_v1::CloudBuildClient(\n google::cloud::cloudbuild_v1::MakeCloudBuildConnection(options));\n }\n\nFollow these links to find examples for other `*Client` classes:\n\n- [`cloudbuild_v1::CloudBuildClient`](/cpp/docs/reference/cloudbuild/2.33.0/cloudbuild_v1_1_1CloudBuildClient-service-account-snippet)\n- [`cloudbuild_v2::RepositoryManagerClient`](/cpp/docs/reference/cloudbuild/2.33.0/cloudbuild_v2_1_1RepositoryManagerClient-service-account-snippet)\n\nKeep in mind that we chose this as an example because it is relatively easy to understand. Consult the [Best practices for managing service account keys](https://cloud.google.com/iam/docs/best-practices-for-managing-service-account-keys) guide for more details.\n\n###### See Also\n\n[Authentication Components](https://cloud.google.com/cpp/docs/reference/common/latest/group__guac.html) - for more information on the factory functions to create [`google::cloud::Credentials`](https://cloud.google.com/cpp/docs/reference/common/latest/classgoogle_1_1cloud_1_1Credentials.html) objects."]]