synchrony-rs

This project is a Rust port of relative/synchrony with additional enhancements for performance and analysis robustness. It targets obfuscation outputs primarily from javascript-obfuscator / obfuscator.io.

Features

• Multiple transformer passes (string decoder, array map, control-flow recovery)
• Fast Rust implementation
• Available as both a CLI and a library

Usage (CLI)

# Install
cargo install synchrony-rs
# cargo install synchrony-rs --locked # (alternative)

# Build from source
cargo build --release

# Run
synchrony ./input.js
# ./target/release/synchrony ./input.js

# Output defaults to ./input.cleaned.js

Usage (Library)

use synchrony_rs::Deobfuscator;

let deob = Deobfuscator::new();
let output = deob.deobfuscate_source("var a = 1;", None).unwrap();
println!("{output}");

Usage (WASM: Browser / Workers)

Build the wasm package (no CLI, wasm-only bindings). On stable Rust, avoid --out-dir and copy the generated pkg/ instead:

# Browser (web target)
wasm-pack build --target web --no-default-features --features wasm
cp -R pkg examples/wasm-web/

# Cloudflare Workers (bundler target)
wasm-pack build --target bundler --no-default-features --features wasm
cp -R pkg examples/wasm-workers/

Note: do not mix web/bundler outputs. The web target is for browsers, the bundler target is for Workers (and other bundlers).

JS example (browser or Workers):

import init, { deobfuscate } from "./pkg/synchrony_rs.js";

await init();
const output = deobfuscate("var a = 1 + 2 + 3;", {
  rename: false,
  sourceType: "script",
  ecmaVersion: "es2020",
});
console.log(output);

See the ready-to-run examples:

• examples/wasm-web
• examples/wasm-workers

Web UI (Cloudflare Pages)

A static web UI lives in public/ and is meant to be deployed with Cloudflare Pages.

Build command (from repo root):

./scripts/build-pages.sh

Pages settings:

• Build command: cargo install wasm-pack --locked && ./scripts/build-pages.sh
• Build output directory: public

Notes:

• The script builds the WASM web target and copies pkg/ into public/pkg/.
• Use --target web for the browser UI. Do not use the bundler output here.

Notes

• Outputs from very old versions of javascript-obfuscator may not deobfuscate correctly. If that happens, try another synchrony version or a different deobfuscator.
• The pipeline runs automatically; user configuration is intentionally minimal.

Troubleshooting

If a transformer fails, you will see a message like:

Error: Transformer error: ...

Please share the full terminal output and the input file (plus a minimal reproduction if possible). Avoid screenshots or partial logs.

Tip: build with the tracing feature (enabled by default) and set RUST_LOG=debug to get more detail about which transformer ran last.