JSSON Language

The universal configuration meta-format. Write once, transpile to JSON, YAML, TOML, or TypeScript.

config.jsson

@preset "api" {
  timeout = 30
  retries = 3
}

users [
  template { id, role }
  map (u) = @use "api" {
    id = @uuid
    email = @email
    role = u.role
    active = yes
  }
  1..5, "admin"
  6..100, "user"
]

Output (100 users)

{
  "users": [
    {
      "timeout": 30,
      "retries": 3,
      "id": "a1b2c3d4-...",
      "email": "user_x@example.com",
      "role": "admin",
      "active": true
    },
    // ... 99 more users
  ]
}

Philosophy

Configuration should be expressive, logic-first, and completely type-safe. Stop repeating yourself across formats.

Key Features

Universal Output

One source file for JSON, YAML, TOML, and TypeScript. Never sync configs manually again.

Logic Built-In

Variables, ranges, map transformations, arithmetic, and conditionals. No external tools needed.

Presets & Validators

Reusable templates with @preset/@use. Auto-generate UUIDs, emails, dates with validators.

HTTP Server

Built-in REST API for transpilation. Perfect for playgrounds, CI/CD, and microservices.

VS Code Extension

Full LSP support with syntax highlighting, diagnostics, auto-complete, and go-to-definition.

Schema Validation

Validate transpiled output against JSON Schema. Catch errors before deployment.

v0.0.6— Presets, Validators, LSP Support