.env File Syntax

How envapt parses .env files, including keys, quoting, escapes, multi-line values, and inline comments.

envapt ships its own .env parser with zero dependencies. This page is the grammar it accepts. For which files load, see Configuration; for ${VAR} interpolation, see Templates.

Keys and values

Each line is KEY=value. An optional export prefix is allowed, so a file you also source in a shell works unchanged.

APP_NAME=envapt
export PORT=3000

A key is letters, digits, and underscores, and does not start with a digit. Leading whitespace around the key and = is ignored. An empty value resolves to an empty string.

EMPTY=

Comments

A line whose first non-whitespace character is # is a comment. An inline # after an unquoted value also starts a comment, but only when preceded by whitespace, so a # inside a value is kept.

# full-line comment
HOST=localhost # inline comment, stripped
COLOR=#ff0000 # kept: the # has no leading space before it

COLOR reads as #ff0000.

Quoting

A value can be wrapped in single quotes, double quotes, or backticks. The quote style decides escape handling, not whether multi-line works (all three support it).

Quote	Escapes	Use it for
`"double"`	decodes `\n` `\r` `\t` `\\` `\"`	values where you want `\n` to become a real newline
`'single'`	none, fully literal	values that should stay exactly as written
`backtick`	none, fully literal	same as single, when the value contains `'`

WARNING

Only double quotes interpret escapes. Inside single quotes or backticks, \n stays as the two characters backslash-n, it does not become a newline. Use double quotes when you want escape decoding.

Multi-line values

A quoted value runs across as many lines as you need: one opening quote, the content, one closing quote. This is how you store a certificate or private key.

TLS_CERT="-----BEGIN CERTIFICATE-----
MIIBkTCB+wIJAKHH...
...more base64...
-----END CERTIFICATE-----"

You read it back as one string, newlines intact:

const cert = .('TLS_CERT');      
const cert: string | undefined

With double quotes you can also keep it on one line and write \n between segments; envapt decodes them. With single quotes or backticks the line breaks must be real (a literal \n stays literal).

Unescaped inner quotes

Like dotenv, envapt matches a quoted value to the rightmost matching quote on the value, so unescaped inner quotes are tolerated.

JSON="{"name":"envapt","port":3000}"

TIP

JSON above round-trips to {"name":"envapt","port":3000} without escaping the inner quotes. Pair it with the Json converter to parse it.

NOTE

The parser stores values literally; it does not expand ${VAR} here. That interpolation runs when you read a value, covered in Templates.