1# Verifying API Access Permissions 2 3## When to Use 4 5To protect sensitive data and eliminate security threats on core abilities, you can use the permissions in the [Application Permission List](permission-list.md) to protect the related API from unauthorized calling. Each time before the API is called, a permission verification is performed to check whether the caller has the required permission. 6 7## Available APIs 8 9The following describes only the API used for permission verification. For more information about the APIs, see [Application Access Control](../reference/apis/js-apis-abilityAccessCtrl.md). 10 11checkAccessToken(tokenID: number, permissionName: Permissions): Promise<GrantStatus> 12 13| Name | Type | Mandatory| Description | 14| -------- | ------------------- | ---- | ------------------------------------------ | 15| tokenID | number | Yes | Token ID of the application. You can obtain the value from the [ApplicationInfo](../reference/apis/js-apis-bundleManager-applicationInfo.md) of the application. | 16| permissionName | Permissions | Yes | Name of the permission to verify. Valid permission names are defined in the [Application Permission List](permission-list.md).| 17 18 19## Example 20 21The procedure is as follows: 22 231. Obtain the caller's identity (**tokenId**). 24 > **NOTE** 25 > 26 > You can use **getCallingTokenId** to obtain the caller's **tokenId**. For details, see [RPC](../reference/apis/js-apis-rpc.md). 272. Determine the permission to verify, which is **ohos.permission.ACCELEROMETER** in this example. 283. Call **checkAccessToken()** to perform a permission verification for the caller. 294. Proceed based on the permission verification result. 30 31```ts 32 import abilityAccessCtrl from '@ohos.abilityAccessCtrl' 33 import { BusinessError } from '@ohos.base'; 34 import rpc from '@ohos.rpc' 35 36 class Stub extends rpc.RemoteObject { 37 onRemoteMessageRequest(code: number, data: rpc.MessageSequence, reply: rpc.MessageSequence, option: rpc.MessageOption) { 38 let callerTokenId: number = rpc.IPCSkeleton.getCallingTokenId(); 39 console.log("RpcServer: getCallingTokenId result: " + callerTokenId); 40 let atManager: abilityAccessCtrl.AtManager = abilityAccessCtrl.createAtManager(); 41 try { 42 atManager.checkAccessToken(callerTokenId, "ohos.permission.ACCELEROMETER").then((data: abilityAccessCtrl.GrantStatus) => { 43 console.log(`checkAccessToken success, data->${JSON.stringify(data)}`); 44 }).catch((err: BusinessError) => { 45 console.log(`checkAccessToken fail, err->${JSON.stringify(err)}`); 46 }); 47 } catch(err) { 48 console.log(`catch err->${JSON.stringify(err)}`); 49 } 50 return true; 51 } 52 } 53``` 54