1# (Optional) Using canOpenLink to Check Application Accessibility 2## When to Use 3Before starting application B, application A can call **canOpenLink** to check whether application B is accessible. 4## Constraints 5A maximum of 50 URL schemes can be configured in the [querySchemes](../quick-start/module-configuration-file.md) field in the **module.json5** file of the entry module. 6## Available APIs 7**canOpenLink** is provided by the [bundleManager](../reference/apis-ability-kit/js-apis-bundleManager.md#bundlemanagercanopenlink12) module to check whether a target application is accessible. 8 9For details about the matching rules, see [Matching Rules of Explicit Want and Implicit Want](explicit-implicit-want-mappings.md). 10 11## How to Develop 12### Procedure for the Caller Application 13 141. Configure the [querySchemes](../quick-start/module-configuration-file.md) field in the **module.json5** file of the entry module to declare the URL schemes. 15 16 ```json 17 { 18 "module": { 19 //... 20 "querySchemes": [ 21 "app1Scheme" 22 ] 23 } 24 } 25 ``` 26 272. Import the **ohos.bundle.bundleManager** module. 283. Call **canOpenLink**. 29 30 ```ts 31 import { bundleManager } from '@kit.AbilityKit'; 32 import { BusinessError } from '@kit.BasicServicesKit'; 33 import { hilog } from '@kit.PerformanceAnalysisKit'; 34 try { 35 let link = 'app1Scheme://test.example.com/home'; 36 let canOpen = bundleManager.canOpenLink(link); 37 hilog.info(0x0000, 'testTag', 'canOpenLink successfully: %{public}s', JSON.stringify(canOpen)); 38 } catch (err) { 39 let message = (err as BusinessError).message; 40 hilog.error(0x0000, 'testTag', 'canOpenLink failed: %{public}s', message); 41 } 42 ``` 43 44### Procedure for the Target Application 45Configure the [uris](../quick-start/module-configuration-file.md#skills) field in the **module.json5** file. 46 47```json 48{ 49 "module": { 50 //... 51 "abilities": [ 52 { 53 //... 54 "skills": [ 55 { 56 "uris": [ 57 { 58 "scheme": "app1Scheme", 59 "host": "test.example.com", 60 "pathStartWith": "home" 61 } 62 ] 63 } 64 ] 65 } 66 ] 67 } 68} 69``` 70