Documentation

Melange is an OpenFGA-to-PostgreSQL compiler. It takes your authorization model (written in OpenFGA DSL) and compiles it into specialized PostgreSQL functions that run permission checks directly inside your database.

What is an Authorization Compiler?

If you’ve used Protocol Buffers, GraphQL Code Generator, or similar tools, you’re familiar with the pattern: define a schema, run a compiler, get optimized code tailored to your exact definitions.

Melange applies this pattern to authorization:

  flowchart LR
    schema["schema.fga<br/>(OpenFGA DSL)"] --> melange["melange<br/>compile"]
    melange --> funcs["PostgreSQL Functions<br/>(check_permission, etc)"]

Instead of a generic runtime that interprets your model at query time, Melange generates purpose-built SQL functions for each relation in your schema. The result is authorization logic that runs as native PostgreSQL code, with all the benefits that brings: transaction awareness, query planning, and zero network hops.

How It Works

Define your model - Write an OpenFGA schema (.fga file) describing types, relations, and permission rules
Compile to SQL - Run melange migrate to generate and install specialized PostgreSQL functions
Query permissions - Call the generated functions from any language or directly in SQL

Read more about Melange’s architecture and how it works here.

Why Compile to PostgreSQL?

Traditional FGA	Melange
Separate authorization service	Authorization lives in your database
Network round-trip for every check	Single SQL query
Eventual consistency with your data	Transaction-aware, always consistent
Generic graph traversal at runtime	Specialized functions per relation
Sync tuples to external store	Query your existing tables directly

Key Features

Specialized Code Generation - Each relation gets its own optimized check function, not a generic interpreter
Works with Your Tables - Permissions derived from a view over your existing data (no tuple sync)
Transaction Aware - Permission checks see uncommitted changes within the same transaction
Language Agnostic - Generated SQL functions callable from Go, Python, Node.js, or any PostgreSQL client
OpenFGA Compatible - Use familiar OpenFGA DSL syntax for authorization models

Quick Start

Getting Started

Install Melange, set up your first schema, and run permission checks

Concepts

Understand the core architecture and design of Melange.

How It Works

Specialized SQL generation, precomputed closures, and sub-millisecond checks

Authorization Modelling

Write OpenFGA schemas to define your permission model

Tuples View

Map your domain tables to authorization tuples

Client Libraries

Melange includes client libraries for convenient access to the generated SQL functions. For direct SQL access from any language, see the SQL API reference.

Checking Permissions

Validate access using the Checker API

Listing Objects

Find all objects a subject can access

Listing Subjects

Find all subjects with access to an object