v__VERSION__

A small, strict language for config and messages.

ANVL — Attributed · Node · Variadic · Language

ANVL is a text format with two dialects — AML for declarative modelling and configuration, and AMP for restricted, scalar-only messaging payloads. This is the JavaScript parser and serializer: pure JS, no runtime dependencies, and a real, working parser you can drop into a browser with one <script> tag.

Try it live → Read the docs Download the bundle

Why not just JSON?

JSON is a fine wire format. It's a rough config format — no comments, no way to reference a value you already defined, no restricted subset for contexts where a payload shouldn't be able to grow arbitrary structure. ANVL exists for the cases where those gaps actually cost you something.

	JSON	ANVL
Comments	Not allowed	`//` and `/* */`
Reference a value you already defined	Copy-paste, or a non-standard `$ref` convention	Native `$identifier`, resolved once at parse time
Extend or override a template	Not supported	Single inheritance — `Child : Base := {...}`
A restricted subset for untrusted-ish payloads	None — any valid JSON is valid JSON	AMP dialect: scalars and scalar collections only, rejected otherwise at parse time
Metadata attached to a field	Invent your own convention	Native `@[key=value]` attributes
Bare identifiers as values	Always quoted strings	Unquoted wherever unambiguous

None of this is exotic on its own — TOML and YAML each solve pieces of it too. ANVL's bet is doing all of it under one strict, unambiguous grammar, plus a second, deliberately restricted dialect for when you want structure but not arbitrary structure.

Why ANVL

Strict by design

Required statement terminators, no ambiguous comment characters, no silent coercions. Mistakes fail to parse instead of quietly meaning the wrong thing.

Two dialects, one grammar core

AML allows full nesting — objects, arrays, tuples, inheritance, one-time $ references. AMP strips it down to scalars and scalar collections only, enforced at parse time, not by convention.

Round-trip capable

Parse to a read-only AnvilNode tree, then write it back out — pretty-printed or minified — and re-parse to the same structure.

A look at AML

#!aml
server @[env = production] := {
    host := localhost;
    port := 8080;
    tags := [edge, cache];
};

// variables can be defined and referenced
var_ref    := 42;
derived_var := $var_ref;

Try it now

The playground runs the actual bundle in your browser — paste ANVL source, parse it, and see the structure and the re-serialized output, live.