faiscadev/fakecloud

What it solves

fakecloud provides a completely free, open-source local emulator for AWS services. It allows developers to perform integration testing and local development without needing an AWS account, authentication tokens, or paying for cloud resources, serving as a drop-in replacement for tools like LocalStack.

How it works

It runs as a single, lightweight binary that emulates 105 AWS services (including S3, DynamoDB, and Lambda) by listening on http://localhost:4566. Developers point their AWS SDKs or CLI to this local endpoint using dummy credentials. For stateful services like RDS or EC2, it manages real containers via Docker or Kubernetes. It also includes first-party test SDKs for multiple languages to allow developers to assert side effects (like sent emails or Lambda invocations) directly in their tests.

Who it’s for

Software engineers and DevOps teams who need a local AWS environment for testing and development, particularly those seeking a fully open-source alternative to proprietary cloud emulators.

Highlights

• Extensive Service Coverage: Emulates 105 services and over 7,000 operations with high conformance validated against AWS Smithy models.
• Zero Friction: No account or auth token required; starts in ~300ms with a tiny memory footprint.
• Bedrock Support: Includes a full emulator for AWS Bedrock, supporting streaming, guardrails, agents, and flows.
• Cross-Service Integration: Supports end-to-end execution for integrations like EventBridge to Step Functions or S3 to Lambda.
• Multi-Language Test SDKs: Dedicated libraries for TypeScript, Python, Go, PHP, Java, and Rust to simplify test assertions.