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_COMPLETION_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "discoveryengine.googleapis.com") used byMakeCompletionServiceConnection().
GOOGLE_CLOUD_CPP_CONTROL_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "discoveryengine.googleapis.com") used byMakeControlServiceConnection().
GOOGLE_CLOUD_CPP_CONVERSATIONAL_SEARCH_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "discoveryengine.googleapis.com") used byMakeConversationalSearchServiceConnection().
GOOGLE_CLOUD_CPP_DATA_STORE_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "discoveryengine.googleapis.com") used byMakeDataStoreServiceConnection().
GOOGLE_CLOUD_CPP_DOCUMENT_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "discoveryengine.googleapis.com") used byMakeDocumentServiceConnection().
GOOGLE_CLOUD_CPP_ENGINE_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "discoveryengine.googleapis.com") used byMakeEngineServiceConnection().
GOOGLE_CLOUD_CPP_GROUNDED_GENERATION_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "discoveryengine.googleapis.com") used byMakeGroundedGenerationServiceConnection().
GOOGLE_CLOUD_CPP_PROJECT_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "discoveryengine.googleapis.com") used byMakeProjectServiceConnection().
GOOGLE_CLOUD_CPP_RANK_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "discoveryengine.googleapis.com") used byMakeRankServiceConnection().
GOOGLE_CLOUD_CPP_RECOMMENDATION_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "discoveryengine.googleapis.com") used byMakeRecommendationServiceConnection().
GOOGLE_CLOUD_CPP_SCHEMA_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "discoveryengine.googleapis.com") used byMakeSchemaServiceConnection().
GOOGLE_CLOUD_CPP_SEARCH_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "discoveryengine.googleapis.com") used byMakeSearchServiceConnection().
GOOGLE_CLOUD_CPP_SITE_SEARCH_ENGINE_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "discoveryengine.googleapis.com") used byMakeSiteSearchEngineServiceConnection().
GOOGLE_CLOUD_CPP_USER_EVENT_SERVICE_ENDPOINT=...overrides theEndpointOption(which defaults to "discoveryengine.googleapis.com") used byMakeUserEventServiceConnection().
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 page details environment variables and version information for the C++ Discovery Engine library, including version history from 2.15.1 to 2.37.0-rc, with 2.37.0-rc being the latest release candidate.\u003c/p\u003e\n"],["\u003cp\u003eSeveral environment variables allow users to override default endpoints for different Discovery Engine services such as Completion, Control, Conversational Search, Data Store, Document, Engine, Grounded Generation, Project, Rank, Recommendation, Schema, Search, Site Search Engine, and User Event.\u003c/p\u003e\n"],["\u003cp\u003eThe environment variables \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_TRACING\u003c/code\u003e, \u003ccode\u003eGOOGLE_CLOUD_CPP_TRACING_OPTIONS\u003c/code\u003e, and \u003ccode\u003eGOOGLE_CLOUD_CPP_ENABLE_CLOG\u003c/code\u003e can be used to configure logging and tracing behaviors for the library, providing tools for troubleshooting and monitoring.\u003c/p\u003e\n"],["\u003cp\u003eWhile \u003ccode\u003eGOOGLE_CLOUD_PROJECT\u003c/code\u003e is used in examples and tests, it does not directly affect the library's functionality, instead allowing for configuration of the GCP project for use in those areas.\u003c/p\u003e\n"]]],[],null,["Version 2.29.0keyboard_arrow_down\n\n- [2.42.0-rc (latest)](/cpp/docs/reference/discoveryengine/latest/discoveryengine-env)\n- [2.41.0](/cpp/docs/reference/discoveryengine/2.41.0/discoveryengine-env)\n- [2.40.0](/cpp/docs/reference/discoveryengine/2.40.0/discoveryengine-env)\n- [2.39.0](/cpp/docs/reference/discoveryengine/2.39.0/discoveryengine-env)\n- [2.38.0](/cpp/docs/reference/discoveryengine/2.38.0/discoveryengine-env)\n- [2.37.0](/cpp/docs/reference/discoveryengine/2.37.0/discoveryengine-env)\n- [2.36.0](/cpp/docs/reference/discoveryengine/2.36.0/discoveryengine-env)\n- [2.35.0](/cpp/docs/reference/discoveryengine/2.35.0/discoveryengine-env)\n- [2.34.0](/cpp/docs/reference/discoveryengine/2.34.0/discoveryengine-env)\n- [2.33.0](/cpp/docs/reference/discoveryengine/2.33.0/discoveryengine-env)\n- [2.32.0](/cpp/docs/reference/discoveryengine/2.32.0/discoveryengine-env)\n- [2.31.0](/cpp/docs/reference/discoveryengine/2.31.0/discoveryengine-env)\n- [2.30.0](/cpp/docs/reference/discoveryengine/2.30.0/discoveryengine-env)\n- [2.29.0](/cpp/docs/reference/discoveryengine/2.29.0/discoveryengine-env)\n- [2.28.0](/cpp/docs/reference/discoveryengine/2.28.0/discoveryengine-env)\n- [2.27.0](/cpp/docs/reference/discoveryengine/2.27.0/discoveryengine-env)\n- [2.26.0](/cpp/docs/reference/discoveryengine/2.26.0/discoveryengine-env)\n- [2.25.1](/cpp/docs/reference/discoveryengine/2.25.1/discoveryengine-env)\n- [2.24.0](/cpp/docs/reference/discoveryengine/2.24.0/discoveryengine-env)\n- [2.23.0](/cpp/docs/reference/discoveryengine/2.23.0/discoveryengine-env)\n- [2.22.1](/cpp/docs/reference/discoveryengine/2.22.1/discoveryengine-env)\n- [2.21.0](/cpp/docs/reference/discoveryengine/2.21.0/discoveryengine-env)\n- [2.20.0](/cpp/docs/reference/discoveryengine/2.20.0/discoveryengine-env)\n- [2.19.0](/cpp/docs/reference/discoveryengine/2.19.0/discoveryengine-env)\n- [2.18.0](/cpp/docs/reference/discoveryengine/2.18.0/discoveryengine-env)\n- [2.17.0](/cpp/docs/reference/discoveryengine/2.17.0/discoveryengine-env)\n- [2.16.0](/cpp/docs/reference/discoveryengine/2.16.0/discoveryengine-env)\n- [2.15.1](/cpp/docs/reference/discoveryengine/2.15.1/discoveryengine-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_COMPLETION_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"discoveryengine.googleapis.com\") used by `MakeCompletionServiceConnection()`.\n- `GOOGLE_CLOUD_CPP_CONTROL_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"discoveryengine.googleapis.com\") used by `MakeControlServiceConnection()`.\n- `GOOGLE_CLOUD_CPP_CONVERSATIONAL_SEARCH_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"discoveryengine.googleapis.com\") used by `MakeConversationalSearchServiceConnection()`.\n- `GOOGLE_CLOUD_CPP_DATA_STORE_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"discoveryengine.googleapis.com\") used by `MakeDataStoreServiceConnection()`.\n- `GOOGLE_CLOUD_CPP_DOCUMENT_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"discoveryengine.googleapis.com\") used by `MakeDocumentServiceConnection()`.\n- `GOOGLE_CLOUD_CPP_ENGINE_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"discoveryengine.googleapis.com\") used by `MakeEngineServiceConnection()`.\n- `GOOGLE_CLOUD_CPP_GROUNDED_GENERATION_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"discoveryengine.googleapis.com\") used by `MakeGroundedGenerationServiceConnection()`.\n- `GOOGLE_CLOUD_CPP_PROJECT_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"discoveryengine.googleapis.com\") used by `MakeProjectServiceConnection()`.\n- `GOOGLE_CLOUD_CPP_RANK_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"discoveryengine.googleapis.com\") used by `MakeRankServiceConnection()`.\n- `GOOGLE_CLOUD_CPP_RECOMMENDATION_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"discoveryengine.googleapis.com\") used by `MakeRecommendationServiceConnection()`.\n- `GOOGLE_CLOUD_CPP_SCHEMA_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"discoveryengine.googleapis.com\") used by `MakeSchemaServiceConnection()`.\n- `GOOGLE_CLOUD_CPP_SEARCH_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"discoveryengine.googleapis.com\") used by `MakeSearchServiceConnection()`.\n- `GOOGLE_CLOUD_CPP_SITE_SEARCH_ENGINE_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"discoveryengine.googleapis.com\") used by `MakeSiteSearchEngineServiceConnection()`.\n- `GOOGLE_CLOUD_CPP_USER_EVENT_SERVICE_ENDPOINT=...` overrides the `EndpointOption` (which defaults to \"discoveryengine.googleapis.com\") used by `MakeUserEventServiceConnection()`.\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."]]
