capo-lambda-core: typed, async Python SDK for AWS Lambda Core¶

capo-lambda-core is a typed Python SDK for AWS Lambda Core. It has an async client, AsyncLambdaCoreClient, for asyncio and trio, and a sync client, LambdaCoreClient, with the same methods. Requests and responses are typed with TypedDicts, so your editor and type checker know every field.

It is part of capo, a community-driven alternative to boto3 and aioboto3, built on its own HTTP stack instead of botocore and generated from the official AWS Smithy models. Documentation: https://capo-sdk.dev/services/lambda-core/

Installation¶

pip install capo-lambda-core

Usage¶

from capo_lambda_core import AsyncLambdaCoreClient


async def main():
    async with AsyncLambdaCoreClient() as lambda_core:
        # Example: call the create_network_connector operation
        response = await lambda_core.create_network_connector()
        print(response["arn"])

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_core import AsyncLambdaCoreClient


async def main():
    async with AsyncLambdaCoreClient() as lambda_core:
        # Example: paginate over list_network_connectors
        async for item in lambda_core.iter_list_network_connectors():
            print(item)

Error Handling¶

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

from capo_lambda_core import AsyncLambdaCoreClient
from capo_lambda_core.error import InvalidParameterValueException


async def main():
    async with AsyncLambdaCoreClient() as lambda_core:
        try:
            await lambda_core.create_network_connector()
        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_core import AsyncLambdaCoreClient


async def main():
    async with AsyncLambdaCoreClient() as lambda_core:
        # Default: 3 attempts for every operation
        response = await lambda_core.create_network_connector()

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

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