Should I use VTL resolvers or JavaScript resolvers in AppSync?

AWS AppSync now supports JavaScript resolvers as an alternative to VTL. JavaScript resolvers are generally easier to write and test. However, VTL resolvers are still widely used in existing projects and are fully supported. Choose based on your team's expertise and project requirements.

What data sources can AppSync resolvers connect to?

AppSync resolvers support DynamoDB, Lambda, OpenSearch (Elasticsearch), Aurora Serverless (via RDS Data API), HTTP endpoints, and EventBridge. Each data source type has its own VTL utility functions and request/response patterns.

AWS AppSync Resolver Builder

ServerlessAWS

Build VTL and JavaScript resolver mapping templates for AppSync GraphQL.

AppSync Configuration

Build VTL and JavaScript resolver mapping templates for AppSync GraphQL.

Required Fields

resolverNamedataSourcerequestTemplaterequestTemplate.versionresponseTemplate

Generated Output

Output will appear here...

About This Tool

The AppSync Resolver Builder helps you construct AWS AppSync VTL (Velocity Template Language) resolver mapping templates for connecting GraphQL operations to data sources. VTL resolvers map GraphQL requests to DynamoDB, Lambda, Elasticsearch, RDS, and HTTP data sources. This tool provides templates for common resolver patterns and guides you through building request and response mapping templates with the correct VTL syntax and utility functions.

When to Use This Tool

•Build DynamoDB resolver templates for GetItem, PutItem, Query, and Scan operations with proper key expressions.
•Create pipeline resolver configurations that chain multiple data sources in a single GraphQL operation.
•Generate resolver templates for batch operations like BatchGetItem and BatchPutItem on DynamoDB tables.
•Build HTTP resolver templates for integrating AppSync with external REST APIs or other AWS services.

Frequently Asked Questions

Should I use VTL resolvers or JavaScript resolvers in AppSync?: AWS AppSync now supports JavaScript resolvers as an alternative to VTL. JavaScript resolvers are generally easier to write and test. However, VTL resolvers are still widely used in existing projects and are fully supported. Choose based on your team's expertise and project requirements.
What data sources can AppSync resolvers connect to?: AppSync resolvers support DynamoDB, Lambda, OpenSearch (Elasticsearch), Aurora Serverless (via RDS Data API), HTTP endpoints, and EventBridge. Each data source type has its own VTL utility functions and request/response patterns.

Related Learning Guides

AWS IAM Best Practices25 min read

Disclaimer: This tool runs entirely in your browser. No data is sent to our servers. Always verify outputs before using them in production. AWS, Azure, and GCP are trademarks of their respective owners.

AWS AppSync Resolver Builder

ServerlessAWS

Build VTL and JavaScript resolver mapping templates for AppSync GraphQL.

AppSync Configuration

Build VTL and JavaScript resolver mapping templates for AppSync GraphQL.

Required Fields

resolverNamedataSourcerequestTemplaterequestTemplate.versionresponseTemplate

Generated Output

Output will appear here...

About This Tool

When to Use This Tool

•Build DynamoDB resolver templates for GetItem, PutItem, Query, and Scan operations with proper key expressions.
•Create pipeline resolver configurations that chain multiple data sources in a single GraphQL operation.
•Generate resolver templates for batch operations like BatchGetItem and BatchPutItem on DynamoDB tables.
•Build HTTP resolver templates for integrating AppSync with external REST APIs or other AWS services.

Frequently Asked Questions

Should I use VTL resolvers or JavaScript resolvers in AppSync?: AWS AppSync now supports JavaScript resolvers as an alternative to VTL. JavaScript resolvers are generally easier to write and test. However, VTL resolvers are still widely used in existing projects and are fully supported. Choose based on your team's expertise and project requirements.
What data sources can AppSync resolvers connect to?: AppSync resolvers support DynamoDB, Lambda, OpenSearch (Elasticsearch), Aurora Serverless (via RDS Data API), HTTP endpoints, and EventBridge. Each data source type has its own VTL utility functions and request/response patterns.

Related Learning Guides

AWS IAM Best Practices25 min read