RDX

The official parser and toolchain for RDX (Reactive Document eXpressions) — a strictly typed, declarative document format built on CommonMark.

RDX documents are pure data. No import, no code execution, no JavaScript runtime. Parse .rdx files into a typed AST from Rust, Node.js, Python, or the browser.

Install

Rust

cargo add rdx-parser

Node.js (native)

npm install @rdx-lang/node

Python

pip install rdx-parser

Browser / Deno / Edge

npm install @rdx-lang/wasm

CLI

cargo install rdx-cli

Usage

use rdx_parser::parse;

let root = parse("# Hello\n\n<Notice type=\"warning\">\n  Be careful.\n</Notice>\n");
println!("{:#?}", root);

import rdx
ast = rdx.parse("# Hello\n\n<Notice type=\"warning\">\n  Be careful.\n</Notice>\n")
print(ast["children"][0]["type"])  # heading

import { parse } from "@rdx-lang/node";
const ast = parse(
  '# Hello\n\n<Notice type="warning">\n  Be careful.\n</Notice>\n',
);
console.log(ast.children[0].type); // heading

Crates

Crate	Description
rdx-ast	AST type definitions with serde serialization
rdx-parser	Parses .rdx documents into a spec-compliant AST
rdx-schema	Schema validation for components — required props, types, enum values
rdx-transform	Composable AST transform pipeline (auto-slug, table of contents)
rdx-github	Optional transform — converts #123, @user, and commit SHAs to links
rdx-wasm	WebAssembly bindings for browsers, Deno, and edge runtimes
rdx-node	Native Node.js bindings via napi-rs
rdx-py	Python bindings via PyO3 — pip install rdx-parser
rdx-cli	CLI — parse, validate, convert MDX→RDX, format

What RDX parses

• Frontmatter — YAML metadata between --- delimiters
• Components — <Notice type="warning"> with five attribute types (string, primitive, JSON, variable, boolean shorthand)
• Context variables — {$frontmatter.title} interpolation in text and attributes
• GFM extensions — tables, strikethrough, task lists, footnotes
• Math — inline $x^2$ and display $$..$$ LaTeX
• Escaping — \{$, \{{, \}}, \{, \\
• Code blocks — fenced code with language tags (variables are not interpolated inside code)
• HTML pass-through — lowercase tags handled per CommonMark rules

All constructs produce dedicated AST node types — no stringly-typed fallbacks.

Schema validation

Define what components your project allows and validate at build time:

use rdx_schema::{Schema, ComponentSchema, PropSchema, PropType, validate};
use rdx_parser::parse;

let schema = Schema::new()
    .strict(true)
    .component("Notice", ComponentSchema::new()
        .prop("type", PropSchema::enum_required(vec!["info", "warning", "error"]))
    );

let root = parse("<Notice type=\"info\">\nContent.\n</Notice>\n");
let diagnostics = validate(&root, &schema);
assert!(diagnostics.is_empty());

Transforms

use rdx_transform::{Pipeline, AutoSlug, TableOfContents};

let root = Pipeline::new()
    .add(AutoSlug::new())
    .add(TableOfContents { min_depth: 2, max_depth: 3, auto_insert: true })
    .run("## Setup\n\n## Usage\n");

CLI

rdx parse document.rdx --pretty        # Output AST as JSON
rdx validate document.rdx --schema s.json  # Validate against schema
rdx convert page.mdx --in-place        # Convert MDX → RDX

Prebuilt binaries available on GitHub Releases.

Building

cargo build
cargo test

Requires Rust 2024 edition (1.85+).

Ecosystem

Repo	Description
rdx	Parser, schema, transforms, and language bindings (this repo)
rdx-js	TypeScript types, JS transform pipeline, and JS-native extensions
tree-sitter-rdx	Syntax highlighting for Neovim, Helix, Zed

Specification

The full language specification is in SPECIFICATION.md.

License

Licensed under either of Apache License, Version 2.0 or MIT License at your option.