## Refresh customer token --- This method refreshes the customer’s current token.
Returns an error if the token has expired and cannot be refreshed.
**Declared In:** Headers/SNRClient.h **Class:** [Client](/developers/mobile-sdk/class-reference/ios/modules#client) **Declaration:**
```Swift static func refreshToken(success: (() -> Void), failure: ((ApiError) -> Void)) -> Void ```
```Objective-C + (void)refreshTokenWithSuccess:(nonnull void (^)(void))success failure:(nonnull void (^)(NSError *error))failure ```
**Parameters:** | Parameter | Type | Mandatory | Default | Description | | --- | --- | --- | --- | --- | | **success** | (() -> Void) | yes | - | Closure/Block to be executed when the operation is completed successfully | | **failure** | (([ApiError](/developers/mobile-sdk/class-reference/ios/miscellaneous#snrapierror)) -> Void) | yes | - | Closure/Block to be executed when the operation is completed with an error | **Return Value:** No value is returned. **Example:**
```Swift Client.refreshToken(success: { _ in Client.retrieveToken(success: { (token) in // success let tokenString: String = token.tokenString let tokenOrigin: TokenOrigin = token.tokenOrigin }, failure: { (error) in // failure }) }, failure: { (error) in // failure }) ```
```Objective-C [SNRClient refreshTokenWithSuccess:^() { [SNRClient retrieveTokenWithSuccess:^(SNRToken *token) { // success NSString *tokenString = token.tokenString; SNRTokenOrigin tokenOrigin = token.tokenOrigin; } failure:^(SNRApiError *error) { // failure }]; } failure:^(SNRApiError *error) { // failure }]; ```
## Retrieve customer token --- This method retrieves the customer’s current, active token.
Returns an error if the token has expired and cannot be retrieved.
**Declared In:** Headers/SNRClient.h **Related To:** [Token](/developers/mobile-sdk/class-reference/ios/client#token) **Class:** [Client](/developers/mobile-sdk/class-reference/ios/modules#client) **Declaration:**
```Swift static func retrieveToken(success: ((Token) -> Void), failure: ((ApiError) -> Void)) -> Void ```
```Objective-C + (void)retrieveTokenWithSuccess:(nonnull void (^)(SNRToken *token))success failure:(nonnull void (^)(NSError *error))failure ```
**Parameters:** | Parameter | Type | Mandatory | Default | Description | | **success** | ((Token) -> Void) | yes | - | Closure/Block to be executed when the operation is completed successfully | | **failure** | (([ApiError](/developers/mobile-sdk/class-reference/ios/miscellaneous#snrapierror)) -> Void) | yes | - | Closure/Block to be executed when the operation is completed with an error | **Return Value:** No value is returned. **Example:**
```Swift Client.retrieveToken(success: { (token) in // success let tokenString: String = token.tokenString let tokenOrigin: TokenOrigin = token.tokenOrigin }, failure: { (error) in // failure }) ```
```Objective-C [SNRClient retrieveTokenWithSuccess:^(SNRToken *token) { // success NSString *tokenString = token.tokenString; SNRTokenOrigin tokenOrigin = token.tokenOrigin; } failure:^(SNRApiError *error) { // failure }]; ```
## Get current customer UUID --- This method retrieves the customer’s current UUID. **Declared In:** Headers/SNRClient.h **Class:** [Client](/developers/mobile-sdk/class-reference/ios/modules#client) **Declaration:**
```Swift static func getUUID() -> String ```
```Objective-C + (NSString *)getUUID; ```
**Return Value:** The method returns the customer's UUID as string. **Example:**
```Swift let clientUUID: String = Client.getUUID() ```
```Objective-C NSString *clientUUID = [SNRClient getUUID]; ```
## Get customer UUID for use in authentication --- This method retrieves the current UUID or generates a new one from a seed. | | **iOS SDK** | **Android SDK** | **React Native SDK** | **Flutter SDK** | | --- | --- | --- | --- | --- | | Introduced in: | 4.15.0 | 5.15.0 | n/a | n/a |
This operation doesn't affect the customer session in the SDK.
**Declared In:** Headers/SNRClient.h **Class:** [Client](/developers/mobile-sdk/class-reference/ios/modules#client) **Declaration:**
```Swift static func getUUIDForAuthentication(authID: String) -> String ```
```Objective-C + (NSString *)getUUIDForAuthenticationWithAuthID:(NSString *)authID ```
**Parameters:** | Parameter | Type | Mandatory | Default | Description | | --- | --- | --- | --- | --- | | **authID** | String | yes | - | Seed for UUID generation | **Return Value:** The method returns the UUID for use in authentication as a string. **Example:**
```Swift let clientUUID: String = Client.getUUIDForAuthentication(authID: "AUTH_ID") ```
```Objective-C NSString *clientUUID = [SNRClient getUUIDForAuthenticationWithAuthID:@"AUTH_ID"]; ```
## Regenerate customer --- This method regenerates the UUID and clears the authentication token, login session, custom email, and custom identifier. This operation works only if the customer is anonymous. This operation clears the authentication token, login (if applicable), custom email, and custom identifier. | | **iOS SDK** | **Android SDK** | **React Native SDK** | **Flutter SDK** | | --- | --- | --- | --- | --- | | Introduced in: | 3.3.10 | 3.3.5 | 0.9.0 | 0.7.0 | **Declared In:** Headers/SNRClient.h **Class:** [Client](/developers/mobile-sdk/class-reference/ios/modules#client) **Declaration:**
```Swift static func regenerateUUID() -> Void ```
```Objective-C + (void)regenerateUUID; ```
**Return Value:** No value is returned. ## Regenerate customer with identifier --- This method regenerates the UUID and clears the authentication token, login session, custom email, and custom identifier. This operation works only if the customer is anonymous. This operation clears the authentication token, login (if applicable), custom email, and custom identifier The optional `clientIdentifier` parameter is a seed for UUID generation. | | **iOS SDK** | **Android SDK** | **React Native SDK** | **Flutter SDK** | | --- | --- | --- | --- | --- | | Introduced in: | 3.6.5 | 3.6.4 | 0.9.10 | 0.7.2 | **Declared In:** Headers/SNRClient.h **Class:** [Client](/developers/mobile-sdk/class-reference/ios/modules#client) **Declaration:**
```Swift static func regenerateUUID(clientIdentifier: String?) -> Void ```
```Objective-C + (void)regenerateUUIDWithClientIdentifier:(NSString *)clientIdentifier; ```
**Parameters:** | Parameter | Type | Mandatory | Default | Description | | --- | --- | --- | --- | --- | | **clientIdentifier** | String | no | - | Seed for UUID generation |
The **clientIdentifier** parameter is used for decreasing the number of UUID refreshes, so it must be unique for every customer.
**Return Value:** No value is returned. ## Destroy current session --- This method destroys the session completely. This method clears all session data (both client and anonymous) and removes cached data. Then, it regenerates the UUID and creates the new anonymous session. **Declared In:** Headers/SNRClient.h **Class:** [Client](/developers/mobile-sdk/class-reference/ios/modules#client) **Declaration:**
```Swift static func destroySession() ```
```Objective-C + (void)destroySession ```
**Return Value:** No value is returned. **Example:**
```Swift Client.destroySession() ```
```Objective-C [SNRClient destroySession]; ```