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_LANGUAGE_SERVICE_ENDPOINT=... overrides the EndpointOption (which defaults to "language.googleapis.com") used by MakeLanguageServiceConnection().
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.
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"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14 UTC."],[[["\u003cp\u003eThis page provides documentation for various versions of the C++ language library, ranging from version 2.11.0 up to the latest release candidate, 2.37.0-rc.\u003c/p\u003e\n"],["\u003cp\u003eThe content details how to configure the library's behavior using environment variables, especially for troubleshooting, including overriding endpoints with \u003ccode\u003eGOOGLE_CLOUD_CPP_LANGUAGE_SERVICE_ENDPOINT\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe documentation explains how to enable gRPC tracing for requests and responses with \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_TRACING\u003c/code\u003e and configure logging behavior with \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eIt outlines how to customize gRPC tracing output using \u003ccode\u003eGOOGLE_CLOUD_CPP_TRACING_OPTIONS\u003c/code\u003e to adjust message formatting and field truncation.\u003c/p\u003e\n"],["\u003cp\u003eIt highlights the use of the \u003ccode\u003eGOOGLE_CLOUD_PROJECT\u003c/code\u003e environment variable in examples and integration tests, clarifying that it does not directly impact the library's functionality.\u003c/p\u003e\n"]]],[],null,[]]
