> For the complete documentation index, see [llms.txt](https://docs.postgresql.tw/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.postgresql.tw/server-programming/oauth-validators/oauth-validator-init.md).

# 50.2. Initialization Functions \#

OAuth validator modules are dynamically loaded from the shared libraries listed in [oauth\_validator\_libraries](/server-administration/runtime-config/runtime-config-connection.md#GUC-OAUTH-VALIDATOR-LIBRARIES). Modules are loaded on demand when requested from a login in progress. The normal library search path is used to locate the library. To provide the validator callbacks and to indicate that the library is an OAuth validator module a function named `_PG_oauth_validator_module_init` must be provided. The return value of the function must be a pointer to a struct of type `OAuthValidatorCallbacks`, which contains a magic number and pointers to the module's token validation functions. The returned pointer must be of server lifetime, which is typically achieved by defining it as a `static const` variable in global scope.

```

typedef struct OAuthValidatorCallbacks
{
    uint32        magic;            /* must be set to PG_OAUTH_VALIDATOR_MAGIC */

    ValidatorStartupCB startup_cb;
    ValidatorShutdownCB shutdown_cb;
    ValidatorValidateCB validate_cb;
} OAuthValidatorCallbacks;

typedef const OAuthValidatorCallbacks *(*OAuthValidatorModuleInit) (void);
```

Only the `validate_cb` callback is required, the others are optional.

***

原文：[PostgreSQL 18.6 Documentation](https://www.postgresql.org/docs/18/oauth-validator-init.html)（英文原文，待翻譯）


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