MiniStack

MiniStack is a local AWS emulator that runs 60+ services in a single container on port 4566. It's built as a free, permanent alternative to LocalStack, which moved most of its core services behind a paid plan. No account, no API key, no telemetry. MIT-licensed with no feature gates.

It starts in under 2 seconds, idles at roughly 30MB of RAM, and ships a Docker image around 270MB. Compare that to LocalStack's ~500MB idle footprint and ~1GB image.

What sets it apart is real infrastructure where it counts:

• RDS spins up actual Postgres or MySQL Docker containers you can connect to with any database client
• ElastiCache starts a real Redis or Memcached container, usable as a session store or pub/sub broker
• ECS RunTask pulls and runs real Docker containers via the Docker socket
• Athena executes genuine SQL through DuckDB when installed, returning real result sets from S3 data
• Lambda runs actual Python with warm workers, SQS event source mapping, and Layers support

Services that were Pro-only on LocalStack, including EMR, EBS, EFS, ALB/ELBv2, EC2, Cognito, CloudFormation, and WAF v2, are all free here.

The full list covers S3, SQS, SNS, DynamoDB, IAM, STS, Secrets Manager, CloudWatch Logs and Metrics, SSM, EventBridge, Kinesis, Step Functions, API Gateway v1 and v2, Glue, Firehose, Route53, Cognito, EC2 with full VPC support, ECR, AppSync, CloudFront, Bedrock (with proxy to Ollama or llama.cpp), IoT Core with MQTT over WebSocket, MWAA with real Airflow containers, and more.

SDK and tooling compatibility is broad:

• Works with boto3, AWS CLI, Terraform, CDK, Pulumi, Java SDK v2, and Go SDK v2
• Terraform users point the aws provider's endpoints at http://localhost:4566 with no other changes
• An official Testcontainers Java module is available on Maven Central for JUnit 5 and Spring Boot setups
• 5,700+ tests pass across Python and Java

Multi-account and multi-region support is included. CloudFormation supports change sets, rollback, and cross-stack export support. Step Functions runs a full ASL engine with sync execution and all state types.

The license is MIT, not BSL. Every service listed is free to use, fork, or embed with no restrictions.