Ministack is a free, open-source local AWS emulator that runs over 60 AWS services on a single port and is compatible with Terraform, AWS SDKs, and infrastructure-as-code tools.
The tool addresses the need for local AWS development and testing without cloud costs or account requirements. It emulates AWS services by running real infrastructure components where practical: RDS spins up actual Postgres or MySQL containers, ElastiCache provisions real Redis or Valkey instances, and ECS executes genuine Docker containers. The emulator supports multi-account and multi-region isolation on a single endpoint by using 12-digit access keys to denote accounts and SigV4 region headers to scope state, mirroring AWS's actual behavior. It includes local Bedrock support that proxies to Ollama, llama.cpp, or vLLM for real language model completions through the standard Bedrock API.
Ministack suits teams that previously relied on LocalStack Community and need a free alternative for local development and CI/CD pipelines. It works as a drop-in replacement with boto3, the AWS CLI, Terraform, CDK, and Pulumi without code changes. The tool's small footprint—around 270MB image size and 30MB idle RAM—and fast startup under two seconds make it practical for resource-constrained environments and rapid test cycles. An internal reset endpoint allows test suites to obtain clean state between runs without container restarts, and optional init script re-execution restores seeded resources.
The project maintains active continuous integration workflows and Docker image distribution. Development activity shows regular updates to the codebase and responsiveness to the build pipeline.
