A number of environment variables can be used to configure the behavior of the library. There are also functions to configure this behavior in code. The environment variables are convenient when troubleshooting problems.
Endpoint Overrides
GOOGLE_CLOUD_CPP_API_KEYS_ENDPOINT=...overrides theEndpointOption(which defaults to "apikeys.googleapis.com") used byMakeApiKeysConnection().
GOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc: turns on tracing for most gRPC calls. The library injects an additional Stub decorator that prints each gRPC request and response. Unless you have configured your own logging backend, you should also setGOOGLE_CLOUD_CPP_ENABLE_CLOGto produce any output on the program's console.
See Also
google::cloud::LoggingComponentsOptionGOOGLE_CLOUD_CPP_TRACING_OPTIONS=...: modifies the behavior of gRPC tracing, including whether messages will be output on multiple lines, or whether string/bytes fields will be truncated.
See Also
google::cloud::GrpcTracingOptionsOptionGOOGLE_CLOUD_CPP_ENABLE_CLOG=yes: turns on logging in the library, basically the library always "logs" but the logging infrastructure has no backend to actually print anything until the application sets a backend or they set this environment variable.
[[["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 document provides environment variable configurations and version history for the Google Cloud C++ API Keys library, specifically focusing on versions ranging from 2.11.0 to 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003eGOOGLE_CLOUD_CPP_API_KEYS_ENDPOINT\u003c/code\u003e environment variable can be used to override the default endpoint for \u003ccode\u003eMakeApiKeysConnection()\u003c/code\u003e, allowing customization of the API endpoint.\u003c/p\u003e\n"],["\u003cp\u003eTracing for gRPC calls can be enabled by setting \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc\u003c/code\u003e, and it requires setting \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG\u003c/code\u003e for console output, alongside enabling logging in the library.\u003c/p\u003e\n"],["\u003cp\u003e\u003ccode\u003eGOOGLE_CLOUD_CPP_TRACING_OPTIONS\u003c/code\u003e allows you to modify gRPC tracing, such as adjusting the format of the output, and \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG=yes\u003c/code\u003e turns on the logging infrastructure for the library to be able to output the logs to the console.\u003c/p\u003e\n"],["\u003cp\u003eThe \u003ccode\u003eGOOGLE_CLOUD_PROJECT\u003c/code\u003e allows setting the project used in examples and integration tests.\u003c/p\u003e\n"]]],[],null,["Version 2.35.0keyboard_arrow_down\n\n- [2.42.0-rc (latest)](/cpp/docs/reference/apikeys/latest/apikeys-env)\n- [2.41.0](/cpp/docs/reference/apikeys/2.41.0/apikeys-env)\n- [2.40.0](/cpp/docs/reference/apikeys/2.40.0/apikeys-env)\n- [2.39.0](/cpp/docs/reference/apikeys/2.39.0/apikeys-env)\n- [2.38.0](/cpp/docs/reference/apikeys/2.38.0/apikeys-env)\n- [2.37.0](/cpp/docs/reference/apikeys/2.37.0/apikeys-env)\n- [2.36.0](/cpp/docs/reference/apikeys/2.36.0/apikeys-env)\n- [2.35.0](/cpp/docs/reference/apikeys/2.35.0/apikeys-env)\n- [2.34.0](/cpp/docs/reference/apikeys/2.34.0/apikeys-env)\n- [2.33.0](/cpp/docs/reference/apikeys/2.33.0/apikeys-env)\n- [2.32.0](/cpp/docs/reference/apikeys/2.32.0/apikeys-env)\n- [2.31.0](/cpp/docs/reference/apikeys/2.31.0/apikeys-env)\n- [2.30.0](/cpp/docs/reference/apikeys/2.30.0/apikeys-env)\n- [2.29.0](/cpp/docs/reference/apikeys/2.29.0/apikeys-env)\n- [2.28.0](/cpp/docs/reference/apikeys/2.28.0/apikeys-env)\n- [2.27.0](/cpp/docs/reference/apikeys/2.27.0/apikeys-env)\n- [2.26.0](/cpp/docs/reference/apikeys/2.26.0/apikeys-env)\n- [2.25.1](/cpp/docs/reference/apikeys/2.25.1/apikeys-env)\n- [2.24.0](/cpp/docs/reference/apikeys/2.24.0/apikeys-env)\n- [2.23.0](/cpp/docs/reference/apikeys/2.23.0/apikeys-env)\n- [2.22.1](/cpp/docs/reference/apikeys/2.22.1/apikeys-env)\n- [2.21.0](/cpp/docs/reference/apikeys/2.21.0/apikeys-env)\n- [2.20.0](/cpp/docs/reference/apikeys/2.20.0/apikeys-env)\n- [2.19.0](/cpp/docs/reference/apikeys/2.19.0/apikeys-env)\n- [2.18.0](/cpp/docs/reference/apikeys/2.18.0/apikeys-env)\n- [2.17.0](/cpp/docs/reference/apikeys/2.17.0/apikeys-env)\n- [2.16.0](/cpp/docs/reference/apikeys/2.16.0/apikeys-env)\n- [2.15.1](/cpp/docs/reference/apikeys/2.15.1/apikeys-env)\n- [2.14.0](/cpp/docs/reference/apikeys/2.14.0/apikeys-env)\n- [2.13.0](/cpp/docs/reference/apikeys/2.13.0/apikeys-env)\n- [2.12.0](/cpp/docs/reference/apikeys/2.12.0/apikeys-env)\n- [2.11.0](/cpp/docs/reference/apikeys/2.11.0/apikeys-env) \n\nEnvironment Variables\n=====================\n\nA number of environment variables can be used to configure the behavior of the library. There are also functions to configure this behavior in code. The environment variables are convenient when troubleshooting problems.\n\nEndpoint Overrides\n------------------\n\n- `GOOGLE_CLOUD_CPP_API_KEYS_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"apikeys.googleapis.com\") used by `MakeApiKeysConnection()`.\n\n###### See Also\n\n[`google::cloud::EndpointOption`](https://cloud.google.com/cpp/docs/reference/common/latest/structgoogle_1_1cloud_1_1EndpointOption.html)\n\nLogging\n-------\n\n`GOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc`: turns on tracing for most gRPC calls. The library injects an additional Stub decorator that prints each gRPC request and response. Unless you have configured your own logging backend, you should also set `GOOGLE_CLOUD_CPP_ENABLE_CLOG` to produce any output on the program's console.\n\n###### See Also\n\n[`google::cloud::LoggingComponentsOption`](https://cloud.google.com/cpp/docs/reference/common/latest/structgoogle_1_1cloud_1_1LoggingComponentsOption.html)`GOOGLE_CLOUD_CPP_TRACING_OPTIONS=...`: modifies the behavior of gRPC tracing, including whether messages will be output on multiple lines, or whether string/bytes fields will be truncated.\n\n###### See Also\n\n[`google::cloud::GrpcTracingOptionsOption`](https://cloud.google.com/cpp/docs/reference/common/latest/structgoogle_1_1cloud_1_1GrpcTracingOptionsOption.html)`GOOGLE_CLOUD_CPP_ENABLE_CLOG=yes`: turns on logging in the library, basically the library always \"logs\" but the logging infrastructure has no backend to actually print anything until the application sets a backend or they set this environment variable.\n\n###### See Also\n\n[`google::cloud::LogBackend`](https://cloud.google.com/cpp/docs/reference/common/latest/classgoogle_1_1cloud_1_1LogBackend.html)\n\n###### See Also\n\n[`google::cloud::LogSink`](https://cloud.google.com/cpp/docs/reference/common/latest/classgoogle_1_1cloud_1_1LogSink.html)\n\nSetting the Default Project\n---------------------------\n\n`GOOGLE_CLOUD_PROJECT=...`: is used in examples and integration tests to configure the GCP project. This has no effect in the library."]]
