An idiomatic C++ client library for thereCAPTCHA Enterprise API. This service helps protect your website from fraudulent activity, spam, and abuse without creating friction.
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/recaptchaenterprise/quickstart/directory, which should give you a taste of the reCAPTCHA Enterprise API C++ client library API.
#include "google/cloud/recaptchaenterprise/v1/recaptcha_enterprise_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 recaptchaenterprise = ::google::cloud::recaptchaenterprise_v1;
auto client = recaptchaenterprise::RecaptchaEnterpriseServiceClient(
recaptchaenterprise::MakeRecaptchaEnterpriseServiceConnection());
auto const project = google::cloud::Project(argv[1]);
for (auto r : client.ListKeys(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;
}
The library automatically retries requests that fail with transient errors, and usesexponential backoffto backoff between retries. Application developers can override the default policies.
More Information
Error Handling- describes how the library reports errors.
[[["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 C++ client library for the reCAPTCHA Enterprise API, designed to protect websites from fraud, spam, and abuse without impacting user experience.\u003c/p\u003e\n"],["\u003cp\u003eThe latest version of the library is 2.37.0-rc, and the page includes documentation and links to past versions such as 2.36.0 down to 2.12.0, allowing users to browse all versions listed.\u003c/p\u003e\n"],["\u003cp\u003eThe library provides the main class \u003ccode\u003erecaptchaenterprise_v1::RecaptchaEnterpriseServiceClient\u003c/code\u003e, which is key for accessing the API's functionalities, including other classes that provide helpers, configuration parameters, and testing infrastructure.\u003c/p\u003e\n"],["\u003cp\u003eThe C++ library automatically manages request retries with exponential backoff for transient errors, but allows developers to customize the default retry policies.\u003c/p\u003e\n"],["\u003cp\u003eThe documentation provides additional information regarding error handling, how to override the default endpoint and authentication, and how environment variables can configure the library's behavior.\u003c/p\u003e\n"]]],[],null,["Version 2.12.0keyboard_arrow_down\n\n- [2.42.0-rc (latest)](/cpp/docs/reference/recaptchaenterprise/latest)\n- [2.41.0](/cpp/docs/reference/recaptchaenterprise/2.41.0)\n- [2.40.0](/cpp/docs/reference/recaptchaenterprise/2.40.0)\n- [2.39.0](/cpp/docs/reference/recaptchaenterprise/2.39.0)\n- [2.38.0](/cpp/docs/reference/recaptchaenterprise/2.38.0)\n- [2.37.0](/cpp/docs/reference/recaptchaenterprise/2.37.0)\n- [2.36.0](/cpp/docs/reference/recaptchaenterprise/2.36.0)\n- [2.35.0](/cpp/docs/reference/recaptchaenterprise/2.35.0)\n- [2.34.0](/cpp/docs/reference/recaptchaenterprise/2.34.0)\n- [2.33.0](/cpp/docs/reference/recaptchaenterprise/2.33.0)\n- [2.32.0](/cpp/docs/reference/recaptchaenterprise/2.32.0)\n- [2.31.0](/cpp/docs/reference/recaptchaenterprise/2.31.0)\n- [2.30.0](/cpp/docs/reference/recaptchaenterprise/2.30.0)\n- [2.29.0](/cpp/docs/reference/recaptchaenterprise/2.29.0)\n- [2.28.0](/cpp/docs/reference/recaptchaenterprise/2.28.0)\n- [2.27.0](/cpp/docs/reference/recaptchaenterprise/2.27.0)\n- [2.26.0](/cpp/docs/reference/recaptchaenterprise/2.26.0)\n- [2.25.1](/cpp/docs/reference/recaptchaenterprise/2.25.1)\n- [2.24.0](/cpp/docs/reference/recaptchaenterprise/2.24.0)\n- [2.23.0](/cpp/docs/reference/recaptchaenterprise/2.23.0)\n- [2.22.1](/cpp/docs/reference/recaptchaenterprise/2.22.1)\n- [2.21.0](/cpp/docs/reference/recaptchaenterprise/2.21.0)\n- [2.20.0](/cpp/docs/reference/recaptchaenterprise/2.20.0)\n- [2.19.0](/cpp/docs/reference/recaptchaenterprise/2.19.0)\n- [2.18.0](/cpp/docs/reference/recaptchaenterprise/2.18.0)\n- [2.17.0](/cpp/docs/reference/recaptchaenterprise/2.17.0)\n- [2.16.0](/cpp/docs/reference/recaptchaenterprise/2.16.0)\n- [2.15.1](/cpp/docs/reference/recaptchaenterprise/2.15.1)\n- [2.14.0](/cpp/docs/reference/recaptchaenterprise/2.14.0)\n- [2.13.0](/cpp/docs/reference/recaptchaenterprise/2.13.0)\n- [2.12.0](/cpp/docs/reference/recaptchaenterprise/2.12.0) \n\nreCAPTCHA Enterprise API C++ Client Library\n===========================================\n\nAn idiomatic C++ client library for the [reCAPTCHA Enterprise API](https://cloud.google.com/recaptcha-enterprise). This service helps protect your website from fraudulent activity, spam, and abuse without creating friction.\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/recaptchaenterprise/quickstart/` directory, which should give you a taste of the reCAPTCHA Enterprise API C++ client library API. \n\n #include \"google/cloud/recaptchaenterprise/v1/recaptcha_enterprise_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 recaptchaenterprise = ::google::cloud::recaptchaenterprise_v1;\n auto client = recaptchaenterprise::RecaptchaEnterpriseServiceClient(\n recaptchaenterprise::MakeRecaptchaEnterpriseServiceConnection());\n\n auto const project = google::cloud::Project(argv[1]);\n for (auto r : client.ListKeys(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 [`recaptchaenterprise_v1::RecaptchaEnterpriseServiceClient`](/cpp/docs/reference/recaptchaenterprise/2.12.0/classgoogle_1_1cloud_1_1recaptchaenterprise__v1_1_1RecaptchaEnterpriseServiceClient). All RPCs are exposed as member functions of this class. Other classes provide helpers, configuration parameters, and infrastructure to mock [`recaptchaenterprise_v1::RecaptchaEnterpriseServiceClient`](/cpp/docs/reference/recaptchaenterprise/2.12.0/classgoogle_1_1cloud_1_1recaptchaenterprise__v1_1_1RecaptchaEnterpriseServiceClient) when testing your application.\n\n### Retry, Backoff, and Idempotency Policies.\n\nThe library automatically retries requests that fail with transient errors, and uses [exponential backoff](https://en.wikipedia.org/wiki/Exponential_backoff) to backoff between retries. Application developers can override the default policies.\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/recaptchaenterprise/2.12.0/recaptchaenterprise-override-endpoint) - describes how to override the default endpoint.\n- [How to Override the Authentication Credentials](/cpp/docs/reference/recaptchaenterprise/2.12.0/recaptchaenterprise-override-authentication) - describes how to change the authentication credentials used by the library.\n- [Environment Variables](/cpp/docs/reference/recaptchaenterprise/2.12.0/recaptchaenterprise-env) - describes environment variables that can configure the behavior of the library."]]