# Type Alias: SystemAuthenticationDef

> **SystemAuthenticationDef** = `AsAuthDef`\<[`HeaderBearerTokenAuthentication`](../../interfaces/HeaderBearerTokenAuthentication/)> | `AsAuthDef`\<[`CustomHeaderTokenAuthentication`](../../interfaces/CustomHeaderTokenAuthentication/)> | `AsAuthDef`\<[`MultiHeaderTokenAuthentication`](../../interfaces/MultiHeaderTokenAuthentication/)> | `AsAuthDef`\<[`QueryParamTokenAuthentication`](../../interfaces/QueryParamTokenAuthentication/)> | `AsAuthDef`\<[`MultiQueryParamTokenAuthentication`](../../interfaces/MultiQueryParamTokenAuthentication/)> | `AsAuthDef`\<[`WebBasicAuthentication`](../../interfaces/WebBasicAuthentication/)> | `AsAuthDef`\<[`AWSAccessKeyAuthentication`](../../interfaces/AWSAccessKeyAuthentication/)> | `AsAuthDef`\<[`AWSAssumeRoleAuthentication`](../../interfaces/AWSAssumeRoleAuthentication/)> | `AsAuthDef`\<`GoogleServiceAccountAuthentication`> | `AsAuthDef`\<[`CustomAuthentication`](../../interfaces/CustomAuthentication/)> | `AsAuthDef`\<[`OAuth2ClientCredentialsAuthentication`](../../interfaces/OAuth2ClientCredentialsAuthentication/)>

Defined in: [types.ts:1006](https://github.com/coda/packs-sdk/blob/44f7744bb692307d51cf2020a7058f343a7e25e8/types.ts#L1006)

The union of supported system authentication definitions. These represent simplified configurations a pack developer can specify when calling [PackDefinitionBuilder.setSystemAuthentication](../../classes/PackDefinitionBuilder/#setsystemauthentication) when using a pack definition builder. The builder massages these definitions into the form of an [SystemAuthentication](../SystemAuthentication/) value, which is the value the platform ultimately cares about.