MiniStack — Free Open-Source Local AWS Emulator

MiniStack is a free, MIT-licensed local AWS emulator offering 33 AWS services on a single port. Positioned as a free alternative to LocalStack (which moved to a paid model), it runs real infrastructure: RDS uses actual Postgres/MySQL containers, ElastiCache runs real Redis, and ECS starts real Docker containers. Key advantages over LocalStack include ~2-second startup time, ~30MB idle memory, a 150MB Docker image, and $0 cost. Supported services include S3, SQS, DynamoDB, Lambda, IAM, SSM, EventBridge, Cognito, EC2, API Gateway, Athena (via DuckDB), Glue, EMR, EBS, EFS, ALB, and more — all free with no account, license key, or telemetry required.