Set environment variables

The current environment variables can be accessed via process.env or Bun.env.

index.ts

Bun.env.API_TOKEN; // => "secret"
process.env.API_TOKEN; // => "secret"

Set these variables in a .env file. Bun reads the following files automatically (listed in order of increasing precedence).

.env
.env.production, .env.development, .env.test (depending on value of NODE_ENV)
.env.local (not loaded when NODE_ENV=test)

.env

FOO=hello
BAR=world

Variables can also be set via the command line.

FOO=helloworld bun run dev

# Using CMD
set FOO=helloworld && bun run dev

# Using PowerShell
$env:FOO="helloworld"; bun run dev

See Docs > Runtime > Environment variables for more information on using environment variables with Bun.