Macro appsync_lambda_main

appsync_lambda_main!() { /* proc-macro */ }

Generates the code required to handle AWS AppSync Direct Lambda resolver events based on a GraphQL schema.

This macro takes a path to a GraphQL schema file and generates the complete foundation for implementing an AWS AppSync Direct Lambda resolver:

• Rust types for all GraphQL types (enums, inputs, objects)
• Query/Mutation/Subscription operation enums
• AWS Lambda runtime setup with logging to handle the AWS AppSync event
• Optional AWS SDK client initialization

Example Usage

use lambda_appsync::appsync_lambda_main;

// If the function returns Some(AppsyncResponse), the Lambda function will immediatly return it
// Else, the normal flow of the AppSync operation processing will continue
// This is primarily intended for advanced authentication checks that AppSync cannot perform,
// such as verifying that a user is requesting their own ID for example.
async fn before_request(
    event: &lambda_appsync::AppsyncEvent<Operation>
) -> Option<lambda_appsync::AppsyncResponse> {
    todo!()
}

appsync_lambda_main!(
    // Path to GraphQL schema file
    "path/to/schema.gql",

    // Optional AWS SDK clients
    dynamodb() -> aws_sdk_dynamodb::Client,
    s3() -> aws_sdk_s3::Client,

    // Options
    batch = true,  // Enable batch request handling
    hook = before_request, // Add custom request hook, typically used for authentication
    field_type_override = MyType.field: CustomType // Override generated field types
);