capo-lambda 0.5.0

Python SDK for AWS Lambda.

Getting Started

Installation

pip install capo-lambda

Usage

from capo_lambda import AsyncLambdaClient


async def main():
    async with AsyncLambdaClient() as s3:
        # Example: call the checkpoint_durable_execution operation
        response = await s3.checkpoint_durable_execution()
        print(response["checkpoint_token"])

Pagination

Some operations in this SDK support pagination. If the operation supports pagination it will have an iter_ prefixed method that returns an async iterator.

from capo_lambda import AsyncLambdaClient


async def main():
    async with AsyncLambdaClient() as s3:
        # Example: paginate over get_durable_execution_history
        async for item in s3.iter_get_durable_execution_history():
            print(item)

Error Handling

The SDK raises exceptions for errors returned by the API. Catch them to handle failures gracefully.

from capo_lambda import AsyncLambdaClient
from capo_lambda.error import InvalidParameterValueException


async def main():
    async with AsyncLambdaClient() as s3:
        try:
            await s3.checkpoint_durable_execution()
        except InvalidParameterValueException as e:
            print(f"Error: {e}")
            print(e.data)  # additional error data

Retrying

The SDK retries failed operations automatically. Retry behaviour follows the Smithy specification: errors are retried based on their is_retryable and is_throttling_error attributes. Throttling errors use a longer base delay. Network-level failures (connection errors and timeouts) are also retried. Non-retryable errors, such as client errors without the @retryable trait, are raised immediately without further attempts.

The number of attempts defaults to 3 and can be changed at the client level via retry_max_attempts, or per call via config_overrides.

from capo_lambda import AsyncLambdaClient


async def main():
    async with AsyncLambdaClient() as s3:
        # Default: 3 attempts for every operation
        response = await s3.checkpoint_durable_execution()

        # Override per operation
        response = await s3.checkpoint_durable_execution(config_overrides={"retry_max_attempts": 5})

        # Disable retries for this call
        response = await s3.checkpoint_durable_execution(config_overrides={"retry_max_attempts": 1})