aiomoto

aiomoto is Moto for aiobotocore (while staying compatible with classic botocore / boto3). It adapts Moto's stubber so async and sync clients share the same in-memory backend: you can write to a mock S3 bucket with boto3 and read it back via aiobotocore in the same process.

📖 Full documentation: https://aiomoto.pages.dev/

Supported today

• mock_aws() usable as with or async with, guarding against real HTTP requests.
• Actively exercised in tests: S3 (CRUD + listings + streaming reads), DynamoDB (create/describe/put/get), Secrets Manager, SES, SNS, SQS, KMS, STS, Lambda, Events, Kafka/MSK, and s3fs async integration — all sharing one Moto backend between sync boto3/botocore and async aiobotocore clients.
• Other Moto services often work out of the box through the same patch layer; if you hit a service-specific gap, open an issue with a minimal repro so we can add a focused slice.

Installation

pip install aiomoto
# or, in a uv project:
uv add aiomoto

aiomoto re-exposes Moto's service extras (for example aiomoto[s3], aiomoto[dynamodb], or aiomoto[all]), plus aiomoto-specific extras (aiomoto[server], aiomoto[pandas], aiomoto[polars]). See the installation guide for details.

Usage

Use aiomoto.mock_aws as a drop-in replacement for Moto's mock_aws that works with both synchronous boto3/botocore clients and asynchronous aiobotocore clients in the same process. It supports with, async with, and decorating sync/async callables.

import boto3
from aiobotocore.session import AioSession
from aiomoto import mock_aws


async def demo() -> None:
    async with mock_aws():
        # Write with a synchronous boto3 client.
        boto3.client("s3", region_name="us-east-1").create_bucket(Bucket="example")

        # Read it back with an async aiobotocore client.
        session = AioSession()
        async with session.create_client("s3", region_name="us-east-1") as s3:
            result = await s3.list_buckets()
            assert any(b["Name"] == "example" for b in result["Buckets"])

The documentation covers more:

• Contexts and decorators — with / async with, @mock_aws, reset / remove_data, and the AWS_ENDPOINT_URL gotcha.
• Server mode — run a local Moto server, endpoint-injection modes, and attaching to an existing server.
• Pandas and Polars — s3:// DataFrame I/O.
• Examples — S3, DynamoDB, SQS, SNS, s3fs, and streaming reads.
• API reference — mock_aws, mock_aws_decorator, AutoEndpointMode, and the exception types.

Motivation

Like many others I've wanted to use Moto with aiobotocore but found that wasn't supported. The motivation page explains the background and why aiomoto avoids depending on Moto's server mode by default.

Limitations

aiomoto keeps version ranges narrow and tested together, and a few integrations (notably pandas/polars S3 I/O) only work in server mode. See the limitations page for the full list, including free-threaded CPython support.