LocalEmu

What is LocalEmu?

LocalEmu emulates 132 AWS services on your machine. Use the same AWS CLI, boto3, Terraform, or CDK you already know - just point to localhost:4566.

Build and test against AWS APIs from your laptop with no account, no credentials, no internet. The iteration loop is seconds instead of minutes; you can break, reset, and rebuild as often as you want at zero cost.

Where it counts, the behavior is real, not stubbed: Lambda runs your code in the official AWS runtime images, EC2 instances are real containers on a real VPC with security groups enforced by actual packet filtering, RDS is a real PostgreSQL or MySQL you can open a connection to, and (with IAM_ENFORCEMENT=1) your identity and resource policies actually deny.

Install

pip install localemu[runtime]

That's it. No Java. No tokens. No accounts. Docker is required for services that emulate by running a real engine in a sidecar (Lambda, ECS, EKS via k3d, RDS, OpenSearch, EC2). Everything else is pure Python and needs no Docker.

Start

Foreground (see the banner and logs)

localemu start

Detached mode (runs in background)

localemu start -d

Custom port

localemu start --port 4567

Stop

localemu stop

Use

LocalEmu ships awsemu - a drop-in replacement for the AWS CLI that automatically points to LocalEmu. No configuration needed:

S3

awsemu s3 mb s3://my-bucket awsemu s3 cp file.txt s3://my-bucket/

DynamoDB

awsemu dynamodb create-table --table-name Users
--key-schema AttributeName=id,KeyType=HASH
--attribute-definitions AttributeName=id,AttributeType=S
--billing-mode PAY_PER_REQUEST

SQS

awsemu sqs create-queue --queue-name my-queue

Lambda

awsemu lambda create-function --function-name hello
--runtime python3.12 --handler handler.handler
--role arn:aws:iam::000000000000:role/role
--zip-file fileb://function.zip

Any of the 132 supported services...

awsemu ecs create-cluster --cluster-name my-cluster awsemu rds describe-db-instances awsemu cognito-idp create-user-pool --pool-name my-pool

awsemu sets credentials, region, and endpoint automatically. You can also use the standard AWS CLI, boto3, Terraform, CDK, or Pulumi - just point to http://localhost:4566.

Documentation & examples

The full documentation lives at localemu.cloud/docs: prerequisites, install guide, per-service API reference, and end-to-end use case walkthroughs.

For runnable code, clone the companion examples repository:

git clone https://github.com/localemu/localemu-examples

It ships self-contained tutorials covering common patterns: public + private VPC with EC2 / nginx / NACL, image pipelines, scheduled jobs, IAM least-privilege drills, Step Functions sagas, EKS + kubectl, chaos resilience tests, and more.