Syntax Transformer

ANTLR Grammar for OpenFGA DSL and JSON Syntax Parser in JavaScript

GrowingOpen SourceLow lock-in

Pricing

Free tier

Flat rate

Adoption

Stable

License

Open Source

Data freshness

Aging · Jun 8, 2026

Overview

What is Syntax Transformer?

Provides a JavaScript implementation of ANTLR Grammar for the OpenFGA DSL, enabling parsing from and to the OpenFGA JSON syntax. Useful for developers working with policy-based access control systems.

Key differentiator

The only JavaScript library providing ANTLR Grammar and JSON Syntax parsing capabilities specifically tailored for the OpenFGA access control system.

Capability profile

Capability Radar

Ease of StartEcosystemValueMaturityFlexibilityScale Ready

Honest assessment

Strengths & Weaknesses

↑ Strengths

ANTLR Grammar for OpenFGA DSLmedium

Parser from and to the OpenFGA JSON Syntaxmedium

Useful for developers working with policy-based access control systemsmedium

↓ Weaknesses

Steep learning curve for non-ANTLR developershigh

Understanding and customizing ANTLR grammars requires deep knowledge of both ANTLR and the OpenFGA DSL.

Limited documentation on advanced use casesmedium

The official documentation lacks detailed examples for complex policy scenarios, making it hard to implement sophisticated access control rules.

Performance overhead due to parsing complexityhigh

ANTLR-based parsing can introduce significant latency in high-throughput applications, impacting real-time performance.

Dependency on ANTLR version compatibilitymedium

The tool's functionality may break or require manual adjustments when upgrading ANTLR versions due to changes in the underlying framework.

Fit analysis

Who is it for?

✓ Best for

Teams building applications that need precise policy-based access controls using the OpenFGA framework

Developers who require a JavaScript library to parse and generate OpenFGA JSON syntax for their projects

✕ Not a fit for

Projects requiring real-time streaming of authorization decisions (this tool is not designed for real-time operations)

Applications that do not use or plan to integrate with the OpenFGA framework

Cost structure

Pricing

Free Tier

Available

Open source — free to use

Starts at

$0

Model

Flat rate

Enterprise

None

Performance benchmarks

How Fast Is It?

Ecosystem

Relationships

Next step

Get Started with Syntax Transformer

Step-by-step setup guide with code examples and common gotchas.

View Setup Guide →