README.md

Goa.Functions.Dynamo

Process DynamoDB Streams events in AWS Lambda with high performance and native AOT support. This package provides a streamlined way to handle DynamoDB change data capture events, supporting both single-record and batch processing patterns with built-in error handling and integration with the Goa DynamoDB mapper for seamless object deserialization.

Quick Start

dotnet new install Goa.Templates
dotnet new goa.dynamodb -n "MyDynamoFunction"

Features

• Flexible Processing Modes: Choose between processing records one at a time or as a batch
• DynamoDB Mapper Integration: Seamlessly deserialize DynamoDB records to strongly-typed objects
• Stream Event Support: Handle INSERT, MODIFY, and REMOVE operations from DynamoDB Streams
• Native AOT Ready: Optimized for ahead-of-time compilation with minimal cold starts
• Error Handling: Built-in support for marking individual records as failed for partial batch failures
• Dependency Injection: Full integration with .NET's dependency injection container
• Type-Safe: Strongly-typed stream records with full IntelliSense support

Basic Usage

using Goa.Functions.Core;
using Goa.Functions.Dynamo;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.DependencyInjection;
using System.Text.Json.Serialization;

await Host.CreateDefaultBuilder()
    .UseLambdaLifecycle()
    .ForDynamoDB()
    .ProcessOneAtATime()
    .HandleWith<IMyService>(async (service, record) =>
    {
        // Process each DynamoDB stream record        if (record.EventName == DynamoStreamOperation.INSERT)
        {
            // DynamoMapper.MyItem is generated by the source generator
            var item = DynamoMapper.MyItem.FromDynamoRecord(record.Dynamodb!.NewImage!);
            await service.ProcessNewItem(item);
        }
    })
    .WithServices(services =>
    {
        // Register your services
        services.AddScoped<IMyService, MyService>();
    })
    .RunAsync();

// Define your model with DynamoDB attributes for source generation
[DynamoModel(PK = "ITEM#<Id>", SK = "META")]
public record MyItem(string Id, string Name, DateTime CreatedAt);

public interface IMyService
{
    Task ProcessNewItem(MyItem item);
}

Documentation

For more information and examples, visit the main Goa documentation.