LocalStack

Everyone's building AI agents. Most of them break in production. Not because the model is bad. Not because the prompt isn't clever enough. But because there's a missing layer between what you tell the agent to do and how it actually does it consistently. That layer is Agent Skills. We just published a new video — "WTH Are Agent Skills?" — that unpacks exactly this. Here's what we cover: → Why agents break (and it's not what you think) → What Agent Skills are and how they fill the gap → Skill file anatomy — what goes in them and why structure matters → MCP vs Skills — how they relate and when to use each → Live demo: deploying skills and smoke testing the results Agent Skills aren't just another abstraction. They're how you take an agent from "impressive demo" to something you'd actually trust in production. Whether you're building with AI agents or considering it, check it out 🎬 https://lnkd.in/ejJqkYgQ

The LocalStack team was meeting the developer community across the 🌍️ today: attending AWS Summit Bengaluru, sponsoring AWS Summit London and keynoting at DevOps Days Atlanta. If you just learned about LocalStack through one of these events (or even if you didn't), be sure to check out our upcoming intro to LocalStack session to get hands-on: https://lnkd.in/euF24BxR

Testing authentication locally is awkward. You need an identity provider running somewhere. Your Lambda functions need to validate tokens against it. Your API Gateway needs to enforce authorization. Most teams either point at a shared dev identity provider — which drifts and conflicts across developers — or skip auth testing locally entirely and hope staging catches the gaps. We built a Keycloak extension for LocalStack that solves this. Install it once, and Keycloak starts automatically alongside your emulated AWS services. It comes pre-configured with a realm, a client, and OIDC provider registration in IAM. Your Lambda authorizers validate real JWTs. Your API Gateway enforces real token-based access. And every LocalStack restart gives you a fresh, deterministic environment — no shared state, no external credentials. In our latest tutorial, we walk through a full example: a user management API built with API Gateway, Lambda, and DynamoDB, protected by Keycloak JWT authorization with role-based access control. You'll see how to: → Install and configure the Keycloak extension → Deploy the stack locally with AWS CDK → Issue tokens via the OAuth2 client credentials flow → Validate JWTs in a Lambda authorizer → Enforce role-based access (admin vs. user) in your CRUD handlers → Test the full auth flow — including what happens without a token If your application uses JWTs for authorization, this extension lets you test those flows properly before they ever touch the cloud. Read the full tutorial: https://lnkd.in/e9siEKGu

Join our April meetup where John Nguyen from E.ON demonstrates how Testcontainers and LocalStack let you run integration tests against realistic AWS services locally. He'll walk through the pitfalls of mock-based testing and show how spinning up real services in Docker containers gives you confidence that your code actually works against emulated services. This session will give you practical techniques for writing integration tests that catch the bugs your unit tests miss.

You've been there. Unit tests pass. CI is green. You deploy with confidence. Then staging reveals bugs that only show up with actual AWS service behavior that your mocks never captured. We're excited to host John Nguyen, Full-Stack Engineer at E.ON, at our next LocalStack Community Meetup. Talk: "Test Your Cloud Like You Mean It: Integrating Testcontainers and LocalStack" 📅 Thursday, April 30 · 11:00 AM – 12:00 PM EDT 🎥 Streaming live on YouTube John will show you how Testcontainers lets you spin up fully emulated AWS services (not mocks) using LocalStack and AWS CDK to write integration tests that actually catch the bugs your unit tests miss. Register for free and get the YouTube Live link in your inbox: https://lnkd.in/ez-rRfpj

Shifting FinOps Concerns: Cost-Governance via Local Cloud Emulation 💻️ Non-production environments often represent a significant portion of AWS expenditures. Over-provisioned resources in dev/test sandboxes contribute to cloud waste... the OPPOSITE of direct business value. 😅 LocalStack emulates AWS services locally on your laptop, empowering engineering teams to shift FinOps concerns to the earliest stages of the Software Development Life Cycle (SDLC). With LocalStack you get... 💸 Zero-Marginal Cost Experimentation Developers can prototype with high-cost services (such as EKS, Kinesis, or MSK) without triggering cloud billing or requiring budget approvals. 🏗️ Infrastructure-as-Code (IaC) Validation Test Terraform or CDK templates locally to catch configuration errors before they reach a live environment, preventing costly "failed state" cleanups. 🔄 Automated Lifecycle Management Local environments are ephemeral by design. A docker-compose down ensures 100% resource reclamation, eliminating the risk of persistent "zombie" resources in the cloud. 🧪 Deterministic CI/CD Running integration tests against a local containerized cloud prevents the accumulation of non-production costs during the continuous testing phase. Decoupling the development loop from the AWS billing console allows you to enforce strict cost-governance while simultaneously increasing developer autonomy. 😎 💪

LocalStack Extensions can facilitate specialized workflows or development needs. This guide walks through using LocalStack's Extensions API to create a mock API for Anthropic, a popular LLM provider, that allows you to test your application code without relying on the live service. Read Here 👉 https://lnkd.in/gjk-PZdg #LocalStack #Extensions #Anthropic #APIMocking #LocalCloudDevelopment #CloudDevelopment

We’re opening applications for the LocalStack Champions program 👩🏽🚀 If you’re building with AWS locally, creating content, or helping other devs, this is for you! Apply here: https://lnkd.in/esr6ykFy ➡️ Applications CLOSE April 30 at 11:59 PM PT.

🚀 New Docs: Snowflake Help & Support We overhauled the Snowflake Help & Support documentation to transition from a hard to find FAQ page to a task-oriented discovery model. The new task-oriented structure highlights... ❄️ Overview A high-level entry point for the Snowflake emulator. ❄️ Get Help Dedicated paths for general troubleshooting and community-led guidance. ❄️ Report an Issue A standardized, efficient workflow for submitting bugs. ❄️ Support Plans Clear technical differentiation between support tiers. ❄️ Enterprise Support Targeted resources specifically for scale and high-availability customers. We're excited to simplify your path to resolutions, allowing you to quickly identify your support resources without friction. 🙌 Explore the new docs here: https://lnkd.in/gSwkaPcb