Learn the YINI Config Format

A clear, 10–15 minute step-by-step guide to the YINI configuration format — covering syntax, structure, and practical features.

Prefer examples? See real YINI configs.

1. Sections

Group settings under a named header. A section header name starts with ^.

Start a section with ^, e.g.:

^ App
title = "AppName"

Alternative section markers to ^ are also supported if ^ is unavailable: <, §, € (e.g. < Section).

See section 9 for more advanced marker and naming options.

2. Key = Value

Each line inside a section is a key (name) and value, separated by =.

Write settings as key = value:

maxConnections = 100
enableLogging  = true

See section 9 for more advanced marker and naming options.

💡Tip

Use backticks (`) to quote section or key names that contain spaces or special characters.

Key names with spaces/special characters can be backticked:

 user id  = 1            # Invalid ❌
`user id` = 1            # Valid ✅

3. Values

Values can be:

  • Strings (always quoted): 'hello', "world", or "C:\Users\john"

    👉 Strings are raw by default — no escape sequences are interpreted.
    Backslashes (\), slashes (/), and even \n are treated as normal text.

  • Numbers: 42, 3.14 or -10

  • Booleans: true, false, on, off, yes, no (all case-insensitive)

  • Nulls: Use null or leave the value blank after = (in lenient mode)

  • Lists:

    • JSON‑style: ["red", "green", "blue"]
    • Colon‑style: (Planned – not yet implemented in parser)

4. Comments

Various commenting styles are supported:

// This is a line comment
timeout = 30  // inline comment
# This is also a line comment (must have a space after #)
interval = 30  # inline comment (must have a space after #)
/* Block comment spanning
   multiple lines */
; Full line comment (must be whole line).

Tip: You can add comments anywhere—above, beside, or below any setting or section.

👆 Caveat 1: If you use # for comments, always put a space after the #. (Otherwise, the parser might misinterpret it as part of a value.)

👆 Caveat 2: ; is used only for full-line comments. The ; must be the first non-whitespace character on a line (only spaces or tabs are allowed before it). (If ; appears later in the line, the parser may treat it as part of a value or as a line delimiter, not as a comment.)

💡Tip: You can use any comment style in your file. For best readability, try to stick to one style per file.

5. Nested Sections

Use extra carets ^ for sub‑sections:

^ Parent
^^ Child

// Add another caret `^` and you get a sub-section
// of the previous section, and so...
^^^ SubChild

If you prefer, you can indent the nested section for visibility:

^ Main
    ^^ Sub
    host = "db.example.com"

One can nest multiple sections:

^ Root
^^ Sub
^^^ SubSub
^ BackToRoot

Example with indented sections:

^ Root
value = 'At level 1'
    ^^ Sub
    value = 'At level 2'
        ^^^ SubSub
        value = 'At level 3'

^ BackToRoot
value = 'Back at level 1'

The above Yini code will produce the following JavaScript object:

// JS object
{
  Root: {
    value: 'At level 1',
    Sub: { value: 'At level 2', SubSub: { value: 'At level 3' } }
  },
  BackToRoot: { value: 'Back at level 1' }
}

See section 9 for more advanced marker and naming options.

6. Lists

// JSON‑style lists
colors = ["red", "green", "blue"]

numberList = [
    10,
    20,
    30
]


// Colon‑style list
// 👆 Colon‑style list support is planned for an upcoming release.
fruits:
  "Pear",
  "Cherry",
  "Banana"

You can use either single or double quotes for string values in YINI.

7. Document Terminator (strict mode)

The /END marker is optional in both lenient (default) and in strict mode.

End a file explicitly with:

^ App
title = "MyTitle"

/END    // Is only optional.

8. Disabled Lines

Prefix any valid line with -- to skip it entirely:

--maxRetries = 5

9. Advanced: Alternative Section Markers & Naming

In addition to the standard syntax, YINI supports several advanced options:

  • (a.) Alternative section markers:
    Besides ^, you can use <, §, or € as section header markers.

    < MySection
§ Settings
€ MyApp

  • (b.) Backticked section names and key names:
    Use backticks (`) to allow spaces or special characters in section or key names:

      ^ `Section name with spaces`
  `user id` = 42

  • (c.) Numeric shorthand section markers:
    To create deeply nested sections (beyond 6 levels), use numeric shorthand:

    ^7 DeepSection    # Equivalent to 7 carets: ^^^^^^^ DeepSection
<10 VeryDeep      # Equivalent to <<<<<<<<<<< VeryDeep

    👆 Though, can not mix standard/classic and numeric shorthand markers in the same section header.

  • (d.) More features:
    The YINI format supports even more features than listed here, such as additional number notations, string types, and advanced escaping. For full details, see the YINI Specification.

10. Complete Example

@yini       # Optional marker to identify YINI format.

^ App
name    = "MyApp"
version = "1.0.0"
debug   = off  // Turn on for debugging.

^^ Database
host     = "db.local"
port     = 5432
--user   = "secret"  # This line is disabled due to --.
userList = ["alice", "bob", "carol"]

/END // (optional)

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