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 library is 2.37.0-rc, and the webpage lists versions from 2.12.0 to 2.37.0-rc, with links to the documentation for each.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003eessentialcontacts_v1::EssentialContactsServiceClient\u003c/code\u003e class is the main class in this library, with all RPCs accessible as member functions.\u003c/p\u003e\n"],["\u003cp\u003eThe provided quickstart guide demonstrates how to use the API to list contacts associated with a project.\u003c/p\u003e\n"],["\u003cp\u003eThe Google Cloud C++ client libraries do not follow Semantic Versioning, and this page provides links to information on error handling, how to override the default endpoint, authentication credentials, retry policies, and environment variables.\u003c/p\u003e\n"]]],[],null,["Version 2.19.0keyboard_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/2.19.0/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/2.19.0/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/2.19.0/essentialcontacts-override-endpoint) - describes how to override the default endpoint.\n- [How to Override the Authentication Credentials](/cpp/docs/reference/essentialcontacts/2.19.0/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/2.19.0/essentialcontacts-override-retry) - describes how to change the default retry policies.\n- [Environment Variables](/cpp/docs/reference/essentialcontacts/2.19.0/essentialcontacts-env) - describes environment variables that can configure the behavior of the library."]]