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_CLOUD_FUNCTIONS_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "cloudfunctions.googleapis.com") used byMakeCloudFunctionsServiceConnection().
GOOGLE_CLOUD_CPP_FUNCTION_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "cloudfunctions.googleapis.com") used byMakeFunctionServiceConnection().
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::TracingComponentsOptionGOOGLE_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 reference information for configuring the behavior of the library using environment variables, including versions ranging from 2.11.0 up to the latest release candidate 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003eEnvironment variables can override default settings, such as endpoint options for both \u003ccode\u003eMakeCloudFunctionsServiceConnection()\u003c/code\u003e and \u003ccode\u003eMakeFunctionServiceConnection()\u003c/code\u003e, using \u003ccode\u003eGOOGLE_CLOUD_CPP_CLOUD_FUNCTIONS_SERVICE_ENDPOINT\u003c/code\u003e and \u003ccode\u003eGOOGLE_CLOUD_CPP_FUNCTION_SERVICE_ENDPOINT\u003c/code\u003e, respectively.\u003c/p\u003e\n"],["\u003cp\u003eTracing for gRPC calls can be enabled with \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_TRACING=rpc\u003c/code\u003e, and logging can be turned on via \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG=yes\u003c/code\u003e, which requires a configured logging backend to actually print output.\u003c/p\u003e\n"],["\u003cp\u003eThe environment variable \u003ccode\u003eGOOGLE_CLOUD_PROJECT\u003c/code\u003e is used to set the GCP project in examples and tests, but does not affect library behavior.\u003c/p\u003e\n"]]],[],null,["Version 2.14.0keyboard_arrow_down\n\n- [2.42.0-rc (latest)](/cpp/docs/reference/functions/latest/functions-env)\n- [2.41.0](/cpp/docs/reference/functions/2.41.0/functions-env)\n- [2.40.0](/cpp/docs/reference/functions/2.40.0/functions-env)\n- [2.39.0](/cpp/docs/reference/functions/2.39.0/functions-env)\n- [2.38.0](/cpp/docs/reference/functions/2.38.0/functions-env)\n- [2.37.0](/cpp/docs/reference/functions/2.37.0/functions-env)\n- [2.36.0](/cpp/docs/reference/functions/2.36.0/functions-env)\n- [2.35.0](/cpp/docs/reference/functions/2.35.0/functions-env)\n- [2.34.0](/cpp/docs/reference/functions/2.34.0/functions-env)\n- [2.33.0](/cpp/docs/reference/functions/2.33.0/functions-env)\n- [2.32.0](/cpp/docs/reference/functions/2.32.0/functions-env)\n- [2.31.0](/cpp/docs/reference/functions/2.31.0/functions-env)\n- [2.30.0](/cpp/docs/reference/functions/2.30.0/functions-env)\n- [2.29.0](/cpp/docs/reference/functions/2.29.0/functions-env)\n- [2.28.0](/cpp/docs/reference/functions/2.28.0/functions-env)\n- [2.27.0](/cpp/docs/reference/functions/2.27.0/functions-env)\n- [2.26.0](/cpp/docs/reference/functions/2.26.0/functions-env)\n- [2.25.1](/cpp/docs/reference/functions/2.25.1/functions-env)\n- [2.24.0](/cpp/docs/reference/functions/2.24.0/functions-env)\n- [2.23.0](/cpp/docs/reference/functions/2.23.0/functions-env)\n- [2.22.1](/cpp/docs/reference/functions/2.22.1/functions-env)\n- [2.21.0](/cpp/docs/reference/functions/2.21.0/functions-env)\n- [2.20.0](/cpp/docs/reference/functions/2.20.0/functions-env)\n- [2.19.0](/cpp/docs/reference/functions/2.19.0/functions-env)\n- [2.18.0](/cpp/docs/reference/functions/2.18.0/functions-env)\n- [2.17.0](/cpp/docs/reference/functions/2.17.0/functions-env)\n- [2.16.0](/cpp/docs/reference/functions/2.16.0/functions-env)\n- [2.15.1](/cpp/docs/reference/functions/2.15.1/functions-env)\n- [2.14.0](/cpp/docs/reference/functions/2.14.0/functions-env)\n- [2.13.0](/cpp/docs/reference/functions/2.13.0/functions-env)\n- [2.12.0](/cpp/docs/reference/functions/2.12.0/functions-env)\n- [2.11.0](/cpp/docs/reference/functions/2.11.0/functions-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_CLOUD_FUNCTIONS_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"cloudfunctions.googleapis.com\") used by `MakeCloudFunctionsServiceConnection()`.\n- `GOOGLE_CLOUD_CPP_FUNCTION_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"cloudfunctions.googleapis.com\") used by `MakeFunctionServiceConnection()`.\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::TracingComponentsOption`](https://cloud.google.com/cpp/docs/reference/common/latest/structgoogle_1_1cloud_1_1TracingComponentsOption.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."]]
