durable-execution-sdk-macros

Procedural macros for the AWS Durable Execution SDK.

Overview

This crate provides the #[durable_execution] attribute macro that transforms an async function into a Lambda handler compatible with the AWS Durable Execution service. You typically don't need to depend on this crate directly — it's re-exported by durable-execution-sdk when the macros feature is enabled (on by default).

Usage

use durable_execution_sdk::{durable_execution, DurableContext, DurableError};
use serde::{Deserialize, Serialize};

#[derive(Deserialize)]
struct MyEvent {
    order_id: String,
}

#[derive(Serialize)]
struct MyResult {
    status: String,
}

#[durable_execution]
async fn my_handler(event: MyEvent, ctx: DurableContext) -> Result<MyResult, DurableError> {
    let result = ctx.step(|_| Ok("processed".to_string()), None).await?;
    Ok(MyResult { status: result })
}

What the macro does

The #[durable_execution] attribute generates two functions from your handler:

An inner async function (__<name>_inner) containing your original logic
A Lambda handler wrapper that accepts LambdaEvent<DurableExecutionInvocationInput> and delegates to run_durable_handler with the inner function

All runtime concerns (event deserialization, state management, context creation, result/error/suspend handling) are encapsulated in run_durable_handler.

Function signature requirements

The decorated function must:

Be async
Have exactly two parameters: (event: EventType, ctx: DurableContext)
Return Result<T, DurableError> where T: Serialize
EventType must implement Deserialize

License