moto-ext
A library that allows you to easily mock out tests based on AWS infrastructure
Decision gist · record as of 2026-08-14
Yes. Active maintenance, low friction, permissive license, and no known vulnerabilities make this a solid choice for local AWS testing. The fork's LocalStack patches add value if you use LocalStack; otherwise, consider whether the upstream Moto project better suits your needs.AI-flagged interpretation of the facts on this page — verify before relying
Before you install
- Requires Python 3.9 or later.
- Active maintenance with a release 4 days ago.
- Low install friction via a pure-Python wheel.
License · maintenance · safety
Apache-2.0 (permissive) — Licensed under Apache-2.0 (permissive), allowing use in commercial and proprietary projects with minimal restrictions.
last release 2026-08-10 (4 days) · last repo commit 2026-08-12 · 27 stars
0 known vulnerabilities (OSV.dev, 2026-08-14) · 253,622 downloads/mo, #8,513 on PyPI
Alternatives
Verify before relying
pip install moto-ext
from moto import mock_s3
import boto3
@mock_s3
def test_s3():
client = boto3.client('s3', region_name='us-east-1')
client.create_bucket(Bucket='test-bucket')
response = client.list_buckets()
assert len(response['Buckets']) == 1- Whether all LocalStack patches are documented or discoverable compared to upstream Moto.
- Performance characteristics when mocking large numbers of AWS resources or complex state.
- Compatibility guarantees with specific AWS service versions or boto3 releases.
What it is and what it does
Moto-ext is a fork of Moto that mocks AWS services for local testing. It intercepts boto3 calls and simulates AWS behavior in-process, letting you test code that depends on AWS without provisioning real infrastructure or incurring costs. The fork includes patches tailored for LocalStack for AWS.
You use it by decorating test functions or context managers to enable mocking for specific services (S3, EC2, DynamoDB, etc.). Your boto3 client calls then hit the mock instead of AWS. It supports a broad surface of AWS services and maintains active development with recent releases.
Use it for
- Unit test code that reads/writes to S3 without creating real buckets or objects.
- Test EC2 instance lifecycle logic (launch, terminate, describe) in isolation.
- Mock DynamoDB tables and queries for rapid iteration on data layer code.
- Integration test multi-service workflows (e.g., Lambda triggering SNS) locally.
- Validate IAM policy logic and role assumptions before deployment.
Worth the install?
AI-flagged interpretation of the facts on this page. Verify before relying on it.
Yes.
Active maintenance, low friction, permissive license, and no known vulnerabilities make this a solid choice for local AWS testing. The fork's LocalStack patches add value if you use LocalStack; otherwise, consider whether the upstream Moto project better suits your needs.
Install
moto-ext on PyPI
Before you install
Active maintenance with a release 4 days ago. Low install friction via a pure-Python wheel. Depends on boto3, botocore, and several common libraries (cryptography, requests, werkzeug, Jinja2, responses) that are widely used and well-maintained.
Requires Python 3.9 or later.
License in practice
Licensed under Apache-2.0 (permissive), allowing use in commercial and proprietary projects with minimal restrictions.
Quickstart
pip install moto-ext
from moto import mock_s3
import boto3
@mock_s3
def test_s3():
client = boto3.client('s3', region_name='us-east-1')
client.create_bucket(Bucket='test-bucket')
response = client.list_buckets()
assert len(response['Buckets']) == 1Verify before relying
- Whether all LocalStack patches are documented or discoverable compared to upstream Moto.
- Performance characteristics when mocking large numbers of AWS resources or complex state.
- Compatibility guarantees with specific AWS service versions or boto3 releases.
Package facts
| License | Apache-2.0 permissive |
| Python support | Supports the current Python release >=3.9 |
| Install friction | Low. Pure-Python wheel |
| Runtime dependencies | 9 packagesboto3botocorecryptographyrequestsxmltodictwerkzeugpython-dateutilresponsesJinja2 |
| Maintenance | Actively maintained 4 days since the last release |
| Last repo commit | |
| First released | |
| Downloads | 253,622 / month, #8,513 on PyPI 30-day window, as of 2026-08-14 |
| Known vulnerabilities | None known OSV.dev, checked 2026-08-14 |
| Classifiers | Programming Language :: Python :: 3Programming Language :: Python :: 3.10Programming Language :: Python :: 3.11Programming Language :: Python :: 3.12Programming Language :: Python :: 3.13Programming Language :: Python :: 3.14Programming Language :: Python :: 3.9Topic :: Software Development :: Testing |
Evidence: moto_ext-5.1.45-py3-none-any.whl
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