AWS, locally.

98 services. One binary. Built-in devtools.

$ npx cloudmock

Three steps. No configuration.

1

Install

One command. No dependencies, no Docker, no cloud account.

npx cloudmock
2

Point your SDK

Override the endpoint in your AWS SDK config.

const client = new S3Client({
  endpoint: "http://localhost:4566",
});
3

Open Devtools

Inspect services, trace requests, and test failure scenarios in the browser.

http://localhost:4500

Everything you need to develop locally

98 AWS Services

S3, DynamoDB, SQS, Lambda, and 94 more. Full API emulation, not stubs. Test your integrations without an AWS account.

Built-in Devtools

Topology map, request tracing, metrics dashboard, and chaos engineering. All accessible at localhost:4500.

6 Language SDKs

Node, Go, Python, Swift, Kotlin, and Dart. Use your existing AWS SDK -- just change the endpoint.

Zero Config

Works out of the box. No Docker required. No cloud account. No YAML files. Start building in seconds.

98 fully emulated AWS services

Complete API coverage for the services you use most. Each service runs in-process with persistent state.

API Gateway
AppSync
CloudFormation
CloudWatch
CloudWatch Logs
Cognito
DynamoDB
ECR
ECS
EventBridge
Firehose
IAM
Kinesis
KMS
Lambda
RDS
Route 53
S3
Secrets Manager
SES
SNS
SQS
SSM
Step Functions
STS

Apache-2.0. Free forever for local development.

CloudMock is open source. Run it locally without limits, inspect the code, and contribute.