# Announcing App Config, Version 2

We're excited to announce a new major version of App Config, a simple but powerful configuration loading library and CLI.

App Config is a great choice for solving the age old configuration question. If you build software applications, you've ran into this need before.

You might have different databases for production and staging, or different API keys for a third party service, or maybe you just want the app to behave differently in different deployments.

What kind of apps? We consider everything from frontend SPAs, Node.js servers, CLI utilities, to non-JavaScript servers. "Jack of all trades" is a stretch, but we're confident that the vast majority of use cases are achievable.

# History

At Launchcode, we had a lot of client applications. Most projects required at least some backend services, one or more frontends, and very often mobile apps. The amount of duplication and repetitiveness of this can easily be imagined. One side of that was configuration. With every service and web page needing to be different between QA, staging and production, it's apparent that something was needed to manage all of it.

As it stands, the ecosystem tends to revolve around .env files. You clone a repo, copy a .env.sample file, and away you go. Then when you need different environments, you make whatever changes are necessary in a somewhat "hardcoded" feeling way. Oftentimes that means statically configuring ENV in dockerfiles, or using custom bash scripts in deployment. Maybe you've gone past that, and implement a "merging" strategy.

Well, if it's not obvious, we weren't happy with that solution. And it turns out, most libraries that solve a similar problem are a bit too specific, niche, or tied to a language. That's not exactly ideal.

Beyond that, it felt like there were no guards in place when using .env. You'd write validation logic manually. That's extremely easy to forget, and easy to mess up.

So instead of re-inventing yet another config library with a JavaScript schema, we went about using JSON Schema. That way, we get the benefit of language agnosticism, strong type constraints, and a highly standard format that's easy to teach.

The evolution of this was very gradual, starting with loading an APP_CONFIG environment variable containing JSON. As needs have arisen, we've found ways to make the developer experience better. The goal of App Config honestly is to make configuration something so easy that you're encouraged to use it more. Anything that could be adjustable, a feature flag, or just environment-specific should be instrumented in your app. This makes DevOps way easier, and reduces a lot of need for re-deployments and small code changes.

# Version 2

We're proud to make a new major version available. It was a full rewrite, using the lessons we learnt in v1. All of that was done with the goal of enabling "encrypted values". By making the workflow of tools like git-crypt (opens new window) a first class citizen, we can ease the onboarding process in new projects. Just trust another user's public key, and now they can deploy to production.

Of course, a central solution like Hashicorp Vault might suit you best. App Config actually intends to support Vault as a config provider in the future! That will enable you to use a "local" workflow, but depend on Vault for production, without ever feeling like switching gears.

Alongside these big features, is the doc pages you're reading right now! We've tried to make App Config accessible to a much wider audience, and hope to get feedback for improvement.

Head on over to the introduction for more about App Config and how you can use it.