goenv

The most over-engineered environment variable reader in the history of Go programming.

goenv reads one environment variable, ENV, and tells you whether you’re in prod or dev. ENV=dev gets you dev. Anything else gets you prod: unset, empty, staging, DEV, a typo. That is on purpose, because if you didn’t explicitly ask for dev I’m not handing it to you.

Install

go get github.com/psyb0t/goenv

The module declares go 1.26 in its go.mod, so you need Go 1.26 or newer. The only import is the standard library os.

Quick look

package main

import (
    "fmt"

    "github.com/psyb0t/goenv"
)

func main() {
    fmt.Println("running in", goenv.Get()) // "prod" or "dev"

    if goenv.IsDev() {
        fmt.Println("break whatever you want")
    }

    if goenv.IsProd() {
        fmt.Println("don't fuck this up")
    }
}

ENV=dev go run .   # running in dev
go run .           # running in prod

Where to go next

You want to	Read
Look up every function and constant, and see which ENV values count as dev	API reference
Install the goenv agent skill in Claude Code, Codex or OpenClaw	Agent integrations
Build, lint and test the library itself, or see how CI and releases run	Development

The Go package docs are on pkg.go.dev, and the source is on GitHub.