AWS Durable Execution SDK for Python

Build reliable, long-running AWS Lambda workflows with checkpointed steps, waits, callbacks, and parallel execution.

✨ Key Features

Automatic checkpointing - Resume execution after Lambda pauses or restarts
Durable steps - Run work with retry strategies and deterministic replay
Waits and callbacks - Pause for time or external signals without blocking Lambda
Parallel and map operations - Fan out work with configurable completion criteria
Child contexts - Structure complex workflows into isolated subflows
Replay-safe logging - Use context.logger for structured, de-duplicated logs
Local and cloud testing - Validate workflows with the testing SDK

📦 Packages

Package	Description	Version
`aws-durable-execution-sdk-python`	Execution SDK for Lambda durable functions
`aws-durable-execution-sdk-python-testing`	Local/cloud test runner and pytest helpers

🚀 Quick Start

Install the execution SDK:

pip install aws-durable-execution-sdk-python

Create a durable Lambda handler:

from aws_durable_execution_sdk_python import (
    DurableContext,
    StepContext,
    durable_execution,
    durable_step,
)
from aws_durable_execution_sdk_python.config import Duration

@durable_step
def validate_order(step_ctx: StepContext, order_id: str) -> dict:
    step_ctx.logger.info("Validating order", extra={"order_id": order_id})
    return {"order_id": order_id, "valid": True}

@durable_execution
def handler(event: dict, context: DurableContext) -> dict:
    order_id = event["order_id"]
    context.logger.info("Starting workflow", extra={"order_id": order_id})

    validation = context.step(validate_order(order_id), name="validate_order")
    if not validation["valid"]:
        return {"status": "rejected", "order_id": order_id}

    # simulate approval (real world: use wait_for_callback)
    context.wait(duration=Duration.from_seconds(5), name="await_confirmation")

    return {"status": "approved", "order_id": order_id}

📚 Documentation

Migrating from 2.x to 3.0 - Upgrade Core and OTel together, migrate plugin registrations and providers, read subtypes as strings, and handle None in batch results
Migrating from 1.x to 2.0 - Earlier breaking changes for applications upgrading from 1.x

The complete documentation for the AWS Durable Execution SDK for Python lives on the AWS Documentation site:

AWS Durable Execution Documentation - Concepts, getting started, core operations, advanced topics, and API reference
AWS Lambda Durable Functions Guide - How durable functions work on Lambda

💬 Feedback & Support

📄 License

See the LICENSE file for our project’s licensing.