Amazon Cognito is a web service that delivers scoped temporary credentials to mobile devices and other untrusted environments. Amazon Cognito uniquely identifies a device and supplies the user with a consistent identity over the lifetime of an application.
Using Amazon Cognito, you can enable authentication with one or more third-party identity providers (Facebook, Google, or Login with Amazon), and you can also choose to support unauthenticated access from your app. Cognito delivers a unique identifier for each user and acts as an OpenID token provider trusted by AWS Security Token Service (STS) to access temporary, limited-privilege AWS credentials.
To provide end-user credentials, first make an unsigned call to GetId. If the end user is authenticated with one of the supported identity providers, set the Logins map with the identity provider token. GetId returns a unique identifier for the user.
Next, make an unsigned call to GetCredentialsForIdentity. This call expects the same Logins map as the GetId call, as well as the IdentityID originally returned by GetId. Assuming your identity pool has been configured via the SetIdentityPoolRoles operation, GetCredentialsForIdentity will return AWS credentials for your use. If your pool has not been configured with SetIdentityPoolRoles, or if you want to follow legacy flow, make an unsigned call to GetOpenIdToken, which returns the OpenID token necessary to call STS and retrieve AWS credentials. This call expects the same Logins map as the GetId call, as well as the IdentityID originally returned by GetId. The token returned by GetOpenIdToken can be passed to the STS operation AssumeRoleWithWebIdentity to retrieve AWS credentials.
If you want to use Amazon Cognito in an Android, iOS, or Unity application, you will probably want to make API calls via the AWS Mobile SDK. To learn more, see the AWS Mobile SDK Developer Guide.
\n\n## Installing\n\nTo install the this package using NPM, simply type the following into a terminal window: \n\n```\nnpm install @aws-sdk/client-cognito-identity-browser\n```\n\n## Getting Started\n\n### Import\n\nThe AWS SDK is modulized by clients and commends in CommonJS modules. To send a request, you only need to import the client(`CognitoIdentityClient`) and the commands you need, for example `CreateIdentityPoolCommand`:\n\n```javascript\n//javascript\nconst { CognitoIdentityClient } = require('@aws-sdk/client-cognito-identity-browser/CognitoIdentityClient');\nconst { CreateIdentityPoolCommand } = require('@aws-sdk/client-cognito-identity-browser/CreateIdentityPoolCommand');\n```\n\n```javascript\n//typescript\nconst { CognitoIdentityClient } = import '@aws-sdk/client-cognito-identity-browser/CognitoIdentityClient';\nconst { CreateIdentityPoolCommand } = import '@aws-sdk/client-cognito-identity-browser/commands/CreateIdentityPoolCommand';\n```\n\n### Usage\n\nTo send a request, you:\n\n* Initiate client with configurations.(credentials, region). For more information you can refer to the [API reference][].\n* Initiate command with input parameters.\n* Call `send` operation of client with command object as input.\n* If you are using a custom http handler, you may call `destroy()` to close open connections. \n\n```javascript\nconst cognitoIdentity = new CognitoIdentityClient({region: 'region'});\n//clients can be shared by different commands\nconst params = {\n IdentityPoolName: /**a string value*/,\n AllowUnauthenticatedIdentities: /**a boolean value*/,\n};\nconst createIdentityPoolCommand = new CreateIdentityPoolCommand(params);\ncognitoIdentity.send(createIdentityPoolCommand).then(data => {\n // do something\n}).catch(error => {\n // error handling\n})\n```\n\nBesides using promise style, there are 2 other ways to send a request:\n\n```javascript\n// async/await\ntry {\n const data = await cognitoIdentity.send(createIdentityPoolCommand);\n // do something\n} catch(error) {\n // error handling\n}\n```\n\n```javascript\n// callback\ncognitoIdentity.send(createIdentityPoolCommand, (err, data) => {\n //do something\n})\n```\n \nBesides using `send()`, the SDK can also send requests using the simplified callback style in version 2 of the SDK.\n\n```javascript\nimport * as AWS from '@aws-sdk/@aws-sdk/client-cognito-identity-browser/CognitoIdentity';\nconst cognitoIdentity = new AWS.CognitoIdentity({region: 'region'})\ncognitoIdentity.createIdentityPool(params, (err, data) => {\n //do something\n})\n\n```\n\n### Troubleshooting \n\nWhen the service returns an exception, inpecting the exceptions is always helpful. You can not only access the exception information but also response metadata(i.e request id).\n\n```javascript\ntry {\n const data = await cognitoIdentity.send(createIdentityPoolCommand);\n // do something\n} catch(error) {\n const metadata = error.$metadata;\n console.log(\n`requestId: ${metadata.requestId}\ncfId: ${metadata.cfId}\nextendedRequestId: ${metadata.extendedRequestId}`\n );\n/*\nThe keys within exceptions are also parsed, you can access them by specifying exception names like below:\n if(error.name === 'SomeServiceException') {\n const value = error.specialKeyInException;\n }\n*/\n}\n```\n\n## Getting Help\n\nPlease use these community resources for getting help. We use the GitHub issues for tracking bugs and feature requests and have limited bandwidth to address them.\n\n * Ask a question on [StackOverflow](https://stackoverflow.com/) and tag it with `aws-sdk-js`\n * Come join the AWS JavaScript community on [gitter](https://gitter.im/aws/aws-sdk-js-v3)\n * If it turns out that you may have found a bug, please [open an issue](https://github.com/aws/aws-sdk-js-v3/issues)\n\n## Contributing\n \nThis client code is generated automatically. Any modifications will be overwritten the next time the `@aws-sdk/@aws-sdk/client-cognito-identity-browser' package is updated. To contribute to SDK you can checkout our [code generator package][].\n\n## License\n\nThis SDK is distributed under the\n[Apache License, Version 2.0](http://www.apache.org/licenses/LICENSE-2.0),\nsee LICENSE for more information.\n\n[code generator package]: https://github.com/aws/aws-sdk-js-v3/tree/master/packages/service-types-generator\n\n[API reference]: https://docs.aws.amazon.com/AWSJavaScriptSDK/latest/\n","_attachments":{},"license":"Apache-2.0"}