Unified Data Access
AWS AppSync uses GraphQL, a data language that enables client apps to fetch, change and subscribe to data from servers. In a GraphQL query, the client specifies how the data is to be structured when it is returned by the server. This makes it possible for the client to query only for the data it needs, in the format that it needs it in. GraphQL also includes a feature called “introspection” which lets new developers on a project discover the data available without requiring knowledge of the backend.
AWS AppSync’s server-side data caching capabilities reduce the need to directly access data sources by making data available in high speed in-memory managed caches, delivering data at low latency. Being fully managed, it eliminates the operational overhead of managing cache clusters. By providing the flexibility to selectively cache data fields and operations defined in the GraphQL schema with customizable expiration, data caching further enables developers to configure optimal performance for their business needs.
Offline data synchronization
The Amplify DataStore is a queryable on-device DataStore for web, mobile and IoT developers that enables a local-first and familiar programming model to interact with data seamlessly whether you’re online or offline. Powered by AWS AppSync, the DataStore provides versioning, conflict detection and resolution in the cloud to automatically merge data from different clients as well as provide data consistency and integrity.
A Merged API composes multiple GraphQL schemas, imports AppSync data sources and resolvers from multiple APIs, and consolidates all resources, combining all the APIs into a single Merged API endpoint that can be exposed to clients. This improves multi-service isolation and minimizes the need for service teams to interact with each other by automating the integration and composition of GraphQL schemas.
Real-time data access and updates
AWS AppSync lets you specify which portions of your data should be available in a real-time manner using GraphQL Subscriptions. GraphQL Subscriptions are simple statements in the application code that tell the service what data should be updated in real-time.
With the subscriptions filtering capabilities in available with AWS AppSync, you can create a broad range of real-time experiences in your applications by leveraging filter operators, server-side filtering, and the ability to trigger subscription invalidations.
Simple pub/sub APIs
If all you want is a an ephemeral API that receives messages published to a channel and delivers those messages in real-time to subscribed clients, you can set up your API without any GraphQL knowledge or experience using AWS AppSyncs PubSub API wizard.
Fine-grained access to control
AWS AppSync allows several levels of data access and authorization depending on the needs of an application. Simple access can be protected by a key and more restrictive permission can be done with AWS Identity and Access Management using Roles. Additionally, AWS AppSync integrates with Amazon Cognito User Pools for email and password functionality, social providers (Facebook, Google+, and Login with Amazon), and enterprise federation with SAML. Customers can use the Group functionality for logical organization of users and roles as well as OAuth features for application access.
Custom domain names
AWS AppSync enables customers to use custom domain names with their AWS AppSync API to access their GraphQl endpoint and real-time endpoint. To create a custom domain name in AppSync, you simply provide a domain name you own and indicate a valid AWS Certificate Manager (ACM) certificate that covers your domain. Once the custom domain name is created, you can associate the domain name with any available AppSync API in your account. After you have updated your DNS record to map to to the AppSync-provided domain name, you can configure your applications to use the new GraphQL and real-time endpoints. You can change the API association on your custom domain at any time without having to update your applications. When AppSync receives a request on the custom domain endpoint, it routes it to the associated API for handling.
With AWS AppSync you can easily configure AWS CloudWatch and AWS X-Ray to provide comprehensive logging and tracing for your GraphQL API.
AWS AppSync offers support for private APIs that can be used to limit API exposure to only within a customer's VPC. Traffic to a private API uses connections that are designed to be secure and does not leave the Amazon network. Customers can also use AWS web application firewall(WAF) to protect their web application and AppSync API from common web exploits, such as SQL injection and cross-site scripting (XSS) attacks.