Many Google Cloud services, such as Cloud Billing, send out notifications to share important information with Google Cloud users. By default, these notifications are sent to members with certain Identity and Access Management (IAM) roles. With theEssential Contacts API, you can customize who receives notifications by providing your own list of contacts.
While this library isGA, please note that the Google Cloud C++ client libraries donotfollowSemantic Versioning.
Quickstart
The following shows the code that you'll run in thegoogle/cloud/essentialcontacts/quickstart/directory, which should give you a taste of the Essential Contacts API C++ client library API.
#include "google/cloud/essentialcontacts/v1/essential_contacts_client.h"
#include "google/cloud/project.h"
#include <iostream>
int main(int argc, char* argv[]) try {
if (argc != 2) {
std::cerr << "Usage: " << argv[0] << " project-id\n";
return 1;
}
namespace essentialcontacts = ::google::cloud::essentialcontacts_v1;
auto client = essentialcontacts::EssentialContactsServiceClient(
essentialcontacts::MakeEssentialContactsServiceConnection());
auto const project = google::cloud::Project(argv[1]);
for (auto r : client.ListContacts(project.FullName())) {
if (!r) throw std::move(r).status();
std::cout << r->DebugString() << "\n";
}
return 0;
} catch (google::cloud::Status const& status) {
std::cerr << "google::cloud::Status thrown: " << status << "\n";
return 1;
}
[[["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 webpage details the Essential Contacts API C++ client library, which allows users to customize who receives important notifications from Google Cloud services.\u003c/p\u003e\n"],["\u003cp\u003eThe latest version of the Essential Contacts API C++ client library is 2.37.0-rc, and the list on this page goes down to version 2.12.0, with links to documentation for each release.\u003c/p\u003e\n"],["\u003cp\u003eThe library's main class is \u003ccode\u003eessentialcontacts_v1::EssentialContactsServiceClient\u003c/code\u003e, which exposes all Remote Procedure Calls (RPCs) as member functions, providing core functionality.\u003c/p\u003e\n"],["\u003cp\u003eThe Google Cloud C++ client libraries, including this Essential Contacts API, do not follow Semantic Versioning conventions.\u003c/p\u003e\n"],["\u003cp\u003eThe webpage offers information on error handling, overriding the default endpoint and authentication, as well as changing the default retry policies.\u003c/p\u003e\n"]]],[],null,["Version 2.26.0keyboard_arrow_down\n\n- [2.42.0-rc (latest)](/cpp/docs/reference/essentialcontacts/latest)\n- [2.41.0](/cpp/docs/reference/essentialcontacts/2.41.0)\n- [2.40.0](/cpp/docs/reference/essentialcontacts/2.40.0)\n- [2.39.0](/cpp/docs/reference/essentialcontacts/2.39.0)\n- [2.38.0](/cpp/docs/reference/essentialcontacts/2.38.0)\n- [2.37.0](/cpp/docs/reference/essentialcontacts/2.37.0)\n- [2.36.0](/cpp/docs/reference/essentialcontacts/2.36.0)\n- [2.35.0](/cpp/docs/reference/essentialcontacts/2.35.0)\n- [2.34.0](/cpp/docs/reference/essentialcontacts/2.34.0)\n- [2.33.0](/cpp/docs/reference/essentialcontacts/2.33.0)\n- [2.32.0](/cpp/docs/reference/essentialcontacts/2.32.0)\n- [2.31.0](/cpp/docs/reference/essentialcontacts/2.31.0)\n- [2.30.0](/cpp/docs/reference/essentialcontacts/2.30.0)\n- [2.29.0](/cpp/docs/reference/essentialcontacts/2.29.0)\n- [2.28.0](/cpp/docs/reference/essentialcontacts/2.28.0)\n- [2.27.0](/cpp/docs/reference/essentialcontacts/2.27.0)\n- [2.26.0](/cpp/docs/reference/essentialcontacts/2.26.0)\n- [2.25.1](/cpp/docs/reference/essentialcontacts/2.25.1)\n- [2.24.0](/cpp/docs/reference/essentialcontacts/2.24.0)\n- [2.23.0](/cpp/docs/reference/essentialcontacts/2.23.0)\n- [2.22.1](/cpp/docs/reference/essentialcontacts/2.22.1)\n- [2.21.0](/cpp/docs/reference/essentialcontacts/2.21.0)\n- [2.20.0](/cpp/docs/reference/essentialcontacts/2.20.0)\n- [2.19.0](/cpp/docs/reference/essentialcontacts/2.19.0)\n- [2.18.0](/cpp/docs/reference/essentialcontacts/2.18.0)\n- [2.17.0](/cpp/docs/reference/essentialcontacts/2.17.0)\n- [2.16.0](/cpp/docs/reference/essentialcontacts/2.16.0)\n- [2.15.1](/cpp/docs/reference/essentialcontacts/2.15.1)\n- [2.14.0](/cpp/docs/reference/essentialcontacts/2.14.0)\n- [2.13.0](/cpp/docs/reference/essentialcontacts/2.13.0)\n- [2.12.0](/cpp/docs/reference/essentialcontacts/2.12.0) \n\nEssential Contacts API C++ Client Library\n=========================================\n\nMany Google Cloud services, such as Cloud Billing, send out notifications to share important information with Google Cloud users. By default, these notifications are sent to members with certain Identity and Access Management (IAM) roles. With the [Essential Contacts API](https://cloud.google.com/essentialcontacts), you can customize who receives notifications by providing your own list of contacts.\n\nWhile this library is **GA** , please note that the 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/essentialcontacts/quickstart/` directory, which should give you a taste of the Essential Contacts API C++ client library API. \n\n #include \"google/cloud/essentialcontacts/v1/essential_contacts_client.h\"\n #include \"google/cloud/project.h\"\n #include \u003ciostream\u003e\n\n int main(int argc, char* argv[]) try {\n if (argc != 2) {\n std::cerr \u003c\u003c \"Usage: \" \u003c\u003c argv[0] \u003c\u003c \" project-id\\n\";\n return 1;\n }\n\n namespace essentialcontacts = ::google::cloud::essentialcontacts_v1;\n auto client = essentialcontacts::EssentialContactsServiceClient(\n essentialcontacts::MakeEssentialContactsServiceConnection());\n\n auto const project = google::cloud::Project(argv[1]);\n for (auto r : client.ListContacts(project.FullName())) {\n if (!r) throw std::move(r).status();\n std::cout \u003c\u003c r-\u003eDebugString() \u003c\u003c \"\\n\";\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 [`essentialcontacts_v1::EssentialContactsServiceClient`](/cpp/docs/reference/essentialcontacts/2.26.0/classgoogle_1_1cloud_1_1essentialcontacts__v1_1_1EssentialContactsServiceClient). All RPCs are exposed as member functions of this class. Other classes provide helpers, configuration parameters, and infrastructure to mock [`essentialcontacts_v1::EssentialContactsServiceClient`](/cpp/docs/reference/essentialcontacts/2.26.0/classgoogle_1_1cloud_1_1essentialcontacts__v1_1_1EssentialContactsServiceClient) 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/essentialcontacts/2.26.0/essentialcontacts-override-endpoint) - describes how to override the default endpoint.\n- [How to Override the Authentication Credentials](/cpp/docs/reference/essentialcontacts/2.26.0/essentialcontacts-override-authentication) - describes how to change the authentication credentials used by the library.\n- [Override Retry, Backoff, and Idempotency Policies](/cpp/docs/reference/essentialcontacts/2.26.0/essentialcontacts-override-retry) - describes how to change the default retry policies.\n- [Environment Variables](/cpp/docs/reference/essentialcontacts/2.26.0/essentialcontacts-env) - describes environment variables that can configure the behavior of the library."]]