hiraeth / sqs / aws emulator

Hiraeth is a local AWS emulator focused on fast integration testing, currently targeting SQS compatibility. It accepts SigV4-signed SDK requests at a local HTTP endpoint, stores state in SQLite, and offers an optional web admin UI for inspecting queues, messages, attributes, and tags. The project provides Docker/Docker Compose images (also published to GitHub Container Registry), a quickstart with seeded test credentials, and instructions for running from source with environment-configurable ports and database path. Many SQS operations are implemented (create/list/send/receive/delete, visibility changes, batch operations), with varying parity to AWS noted. Hiraeth is explicitly for local development and not a production AWS replacement.

A developer launched Hiraeth, a lightweight AWS emulator focused initially on SQS as an alternative to LocalStack after recent pricing/licensing changes. The project emphasizes a small 4MB Docker image, instant startup, AWS SigV4 authentication, and an admin UI for development and troubleshooting. Most of the SQS API is already implemented, with additional AWS services planned. This matters for teams seeking low-cost, fast local testing of AWS services and for developers wary of vendor lock-in or escalating costs from LocalStack. Hiraeth could reduce development friction and resource overhead when building or testing cloud-native apps locally.

A developer published Hiraeth, a lightweight AWS emulator focused on SQS, as an alternative after LocalStack changed its pricing/licensing. The project aims for a minimal footprint—a 4MB Docker image with instant startup—implements AWS SigV4 authentication, provides a small admin UI for debugging, and supports most of the SQS API with more services planned. The post appeared on Hacker News and prompted questions about use cases (local integration testing vs. using real AWS with smaller instances) and suggestions like adding simulated billing. Hiraeth matters because teams seeking low-cost, local emulation for cloud-dependent development and CI may prefer compact, fast emulators over heavier commercial tools.

Fakecloud is a new free, open-source local AWS emulator that provides a single-binary, fully local testing environment compatible with AWS SDKs at http://localhost:4566. It was created after LocalStack moved its community edition to a proprietary image in March 2026. Fakecloud implements 22 AWS services (1,668 operations) with Smithy-model validation, Terraform TestAcc compatibility, and real cross-service wiring (e.g., EventBridge→Step Functions, S3→Lambda). It runs stateful components using Docker where needed (Lambda runtimes, RDS, ElastiCache), offers first-party test SDKs for major languages, and optional SigV4 and IAM enforcement. The project aims to preserve offline, account-free integration testing for teams relying on AWS-like infrastructure locally.

Fakecloud, a free open-source AWS emulator, launched to provide a fully local integration testing environment after LocalStack made its community edition proprietary in March 2026. Distributed as a single ~19 MB binary (no account or auth token required), fakecloud exposes an AWS-compatible endpoint (localhost:4566) and implements 22 services with 1,668 operations, validating each operation against AWS Smithy models and running extensive Terraform acceptance tests. It supports real cross-service wiring (EventBridge→Step Functions, S3→Lambda, SES inbound flows), runs stateful services in real containers (Lambda, RDS, ElastiCache), and offers first-party test SDKs (TS, Python, Go, Java, Rust). Optional SigV4 verification and IAM enforcement aim to balance test convenience with fidelity. The project targets teams needing reliable, local AWS testing without vendor lock-in.