Goenv

goenv

A Go library that reads a single environment variable — ENV — and answers one question: are you in prod or dev? That's the whole package. os.Getenv("ENV") with a fail-safe default and three named helpers, zero dependencies. Import it and call goenv.Get().

For install, the exact match/default behavior, and a worked example, see references/setup.md.

Security & safety

• It reads exactly one environment variable — ENV — and nothing else. No other env vars are read, nothing is written to disk, no network calls are made at runtime, and no data leaves your process. Its only import is the stdlib os.
• It's a library you compile into your own binary — it has no runtime surface of its own. Whatever your program does with the prod/dev answer is on you, same as any code you'd write by hand.
• Fail-safe by design: an unrecognized or unset ENV resolves to prod, so a misconfigured environment errs toward production-grade behavior rather than accidentally enabling dev-only shortcuts.

When to use

• A Go program needs a small, dependency-free way to branch behavior between two environments (prod vs dev) — e.g. verbose logging in dev, stricter defaults in prod.
• The project already imports github.com/psyb0t/goenv and you want to add or read a prod/dev check consistently (goenv.IsProd() / goenv.IsDev() instead of hand-rolled os.Getenv comparisons).
• You want the fail-safe "default to prod" semantics without writing the switch yourself.

When NOT to use

• You need more than two environments (staging, test, ci, local, …) — goenv only knows dev and prod; everything that isn't exactly "dev" collapses to prod.
• You need to read env vars other than ENV, or a configurable variable name — goenv reads the hardcoded ENV and nothing else. Reach for a real config library (e.g. gonfiguration) for anything richer.
• You expect compile-time type safety from the Type type — it's a string alias, so goenv.Type is string; the constants are conveniences, not an enum, and any string is assignable. If you need a distinct nominal type, this isn't it.

Usage

import "github.com/psyb0t/goenv"

// The current environment as a string ("prod" or "dev"):
switch goenv.Get() {
case goenv.Dev:
    // dev-only behavior
default: // goenv.Prod
    // prod behavior
}

// Or the boolean shortcuts:
if goenv.IsDev() {
    logger.SetLevel("debug")
}
if goenv.IsProd() {
    enableStrictMode()
}

// The recognized values and the variable name are exported constants:
_ = goenv.Prod         // "prod"
_ = goenv.Dev          // "dev"
_ = goenv.EnvVarName   // "ENV"

The mapping is exact: Get() returns Dev only when ENV is precisely "dev"; every other value — unset, empty, "DEV", "development", "prod", or anything else — returns Prod. Set it before your process starts:

ENV=dev  ./yourapp     # dev
ENV=prod ./yourapp     # prod
./yourapp              # ENV unset → prod (the default)

For the module path, supported Go version, and the full behavior table, see references/setup.md.