An idiomatic C++ client library for the Policy Troubleshooter, a service that makes it easier to understand why a user has access to a resource or doesn't have permission to call an API.
While this library is GA, please note Google Cloud C++ client libraries do not follow Semantic Versioning.
Quickstart
The following shows the code that you'll run in the google/cloud/policytroubleshooter/quickstart/ directory, which should give you a taste of the Policy Troubleshooter API C++ client library API.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14 UTC."],[[["\u003cp\u003eThis webpage details the C++ client library for the Policy Troubleshooter API, which aids in understanding user access to resources and API permissions.\u003c/p\u003e\n"],["\u003cp\u003eThe library's primary class is \u003ccode\u003epolicytroubleshooter_v1::IamCheckerClient\u003c/code\u003e, which exposes all Remote Procedure Calls (RPCs) as member functions.\u003c/p\u003e\n"],["\u003cp\u003eVersion 2.37.0-rc is the latest version available, while the list contains the versions down to 2.11.0.\u003c/p\u003e\n"],["\u003cp\u003eThe provided quickstart example demonstrates how to use the \u003ccode\u003eIamCheckerClient\u003c/code\u003e to check if a principal has a certain permission on a given resource, which is crucial for troubleshooting access.\u003c/p\u003e\n"],["\u003cp\u003eThe documentation includes guides on error handling, overriding default endpoints and authentication credentials, and configuring retry policies and behavior.\u003c/p\u003e\n"]]],[],null,["Version 2.13.0keyboard_arrow_down\n\n- [2.42.0-rc (latest)](/cpp/docs/reference/policytroubleshooter/latest)\n- [2.41.0](/cpp/docs/reference/policytroubleshooter/2.41.0)\n- [2.40.0](/cpp/docs/reference/policytroubleshooter/2.40.0)\n- [2.39.0](/cpp/docs/reference/policytroubleshooter/2.39.0)\n- [2.38.0](/cpp/docs/reference/policytroubleshooter/2.38.0)\n- [2.37.0](/cpp/docs/reference/policytroubleshooter/2.37.0)\n- [2.36.0](/cpp/docs/reference/policytroubleshooter/2.36.0)\n- [2.35.0](/cpp/docs/reference/policytroubleshooter/2.35.0)\n- [2.34.0](/cpp/docs/reference/policytroubleshooter/2.34.0)\n- [2.33.0](/cpp/docs/reference/policytroubleshooter/2.33.0)\n- [2.32.0](/cpp/docs/reference/policytroubleshooter/2.32.0)\n- [2.31.0](/cpp/docs/reference/policytroubleshooter/2.31.0)\n- [2.30.0](/cpp/docs/reference/policytroubleshooter/2.30.0)\n- [2.29.0](/cpp/docs/reference/policytroubleshooter/2.29.0)\n- [2.28.0](/cpp/docs/reference/policytroubleshooter/2.28.0)\n- [2.27.0](/cpp/docs/reference/policytroubleshooter/2.27.0)\n- [2.26.0](/cpp/docs/reference/policytroubleshooter/2.26.0)\n- [2.25.1](/cpp/docs/reference/policytroubleshooter/2.25.1)\n- [2.24.0](/cpp/docs/reference/policytroubleshooter/2.24.0)\n- [2.23.0](/cpp/docs/reference/policytroubleshooter/2.23.0)\n- [2.22.1](/cpp/docs/reference/policytroubleshooter/2.22.1)\n- [2.21.0](/cpp/docs/reference/policytroubleshooter/2.21.0)\n- [2.20.0](/cpp/docs/reference/policytroubleshooter/2.20.0)\n- [2.19.0](/cpp/docs/reference/policytroubleshooter/2.19.0)\n- [2.18.0](/cpp/docs/reference/policytroubleshooter/2.18.0)\n- [2.17.0](/cpp/docs/reference/policytroubleshooter/2.17.0)\n- [2.16.0](/cpp/docs/reference/policytroubleshooter/2.16.0)\n- [2.15.1](/cpp/docs/reference/policytroubleshooter/2.15.1)\n- [2.14.0](/cpp/docs/reference/policytroubleshooter/2.14.0)\n- [2.13.0](/cpp/docs/reference/policytroubleshooter/2.13.0)\n- [2.12.0](/cpp/docs/reference/policytroubleshooter/2.12.0)\n- [2.11.0](/cpp/docs/reference/policytroubleshooter/2.11.0) \n\nPolicy Troubleshooter API C++ Client Library\n============================================\n\nAn idiomatic C++ client library for the [Policy Troubleshooter](https://cloud.google.com/iam/docs/troubleshooting-access), a service that makes it easier to understand why a user has access to a resource or doesn't have permission to call an API.\n\nWhile this library is **GA** , please note Google Cloud C++ client libraries do **not** follow [Semantic Versioning](https://semver.org/).\n\n### Quickstart\n\nThe following shows the code that you'll run in the `google/cloud/policytroubleshooter/quickstart/` directory, which should give you a taste of the Policy Troubleshooter API C++ client library API. \n\n #include \"google/cloud/policytroubleshooter/v1/iam_checker_client.h\"\n #include \u003ciostream\u003e\n\n int main(int argc, char* argv[]) try {\n if (argc != 4) {\n std::cerr \u003c\u003c \"Usage: \" \u003c\u003c argv[0] \u003c\u003c \" principal resource-name\"\n \u003c\u003c \" permission\\n\";\n return 1;\n }\n\n namespace policytroubleshooter = ::google::cloud::policytroubleshooter_v1;\n auto client = policytroubleshooter::IamCheckerClient(\n policytroubleshooter::MakeIamCheckerConnection());\n\n google::cloud::policytroubleshooter::v1::TroubleshootIamPolicyRequest request;\n auto& access_tuple = *request.mutable_access_tuple();\n access_tuple.set_principal(argv[1]);\n access_tuple.set_full_resource_name(argv[2]);\n access_tuple.set_permission(argv[3]);\n auto const response = client.TroubleshootIamPolicy(request);\n if (!response) throw std::move(response).status();\n std::cout \u003c\u003c response-\u003eDebugString() \u003c\u003c \"\\n\";\n\n return 0;\n } catch (google::cloud::Status const& status) {\n std::cerr \u003c\u003c \"google::cloud::Status thrown: \" \u003c\u003c status \u003c\u003c \"\\n\";\n return 1;\n }\n\n### Main classes\n\nThe main class in this library is [`policytroubleshooter_v1::IamCheckerClient`](/cpp/docs/reference/policytroubleshooter/2.13.0/classgoogle_1_1cloud_1_1policytroubleshooter__v1_1_1IamCheckerClient). All RPCs are exposed as member functions of this class. Other classes provide helpers, configuration parameters, and infrastructure to mock [`policytroubleshooter_v1::IamCheckerClient`](/cpp/docs/reference/policytroubleshooter/2.13.0/classgoogle_1_1cloud_1_1policytroubleshooter__v1_1_1IamCheckerClient) when testing your application.\n\n### More Information\n\n- [Error Handling](https://cloud.google.com/cpp/docs/reference/common/latest/common-error-handling.html) - describes how the library reports errors.\n- [How to Override the Default Endpoint](/cpp/docs/reference/policytroubleshooter/2.13.0/policytroubleshooter-override-endpoint) - describes how to override the default endpoint.\n- [How to Override the Authentication Credentials](/cpp/docs/reference/policytroubleshooter/2.13.0/policytroubleshooter-override-authentication) - describes how to change the authentication credentials used by the library.\n- [Override Retry, Backoff, and Idempotency Policies](/cpp/docs/reference/policytroubleshooter/2.13.0/policytroubleshooter-override-retry) - describes how to change the default retry policies.\n- [Environment Variables](/cpp/docs/reference/policytroubleshooter/2.13.0/policytroubleshooter-env) - describes environment variables that can configure the behavior of the library."]]