Skir is a modern declarative schema language for data models and APIs.
Write once in a .skir file - instantly generate clean, idiomatic, and fully type-safe code in TypeScript, Python, Java, Go, C++, and more languages.
- 🧩 One schema, 10+ languages, zero headaches - One YAML config, one command, and watch mode that refreshes generated code on every change.
- 🛡️ End-to-end type safety - Shared method and type definitions keep client/server contracts aligned before runtime.
- ⚡ SkirRPC + Studio - Lightweight HTTP RPC with a built-in Studio app for browsing and testing methods.
- 📦 GitHub imports - Import types directly from GitHub repositories to share data structures across projects.
- 🔁 Serialization modes - Dense JSON for APIs/DBs, readable JSON for debugging, and binary for raw performance.
- 🧬 Polymorphism done right - Sum types let variants be constants or carry typed payloads for clean, explicit polymorphism.
- 🕰️ Safe schema evolution - Built-in checks and clear rules so old and new data remain deserializable.
- 🔒 Prioritizes immutability - Skir generates deeply immutable types with all fields required at construction time.
- 🗂️ Key-indexed arrays - Declare arrays like
[User|user_id]and get fast key-based lookup APIs. - 🛠️ First-class tooling - VS Code extension + LSP with validation, completion, and auto-formatting.
- 🧱 Easy to extend - Generators are regular NPM modules, so custom generators plug in cleanly.
// robot.skir
enum RobotAction {
wave;
say: string;
move: Point;
}
struct Point {
x: int32;
y: int32;
}
const GREET_ACTIONS: [RobotAction] = [
"wave",
{
kind: "say",
value: "Hi!",
},
];
method PerformAction(RobotAction): bool = 12345;Skir compiles these definitions into native, type-safe code you can use in your project:
# my_project.py
from skirout.robot_skir import Point, RobotAction
wave = RobotAction.WAVE
say_hi = RobotAction.wrap_say("Hi!")
move_origin = RobotAction.wrap_move(Point(x=0, y=0))
# Round-trip serialization to JSON
action_json = RobotAction.serializer.to_json(say_hi)
restored = RobotAction.serializer.from_json(action_json)
assert restored == say_hi
assert move_origin.union.kind == "move"- Getting started: setup & workflow
- Language reference
- Serialization
- Schema evolution
- SkirRPC
- Github imports
- Coming from Protocol Buffer
| Language | Documentation | Example |
|---|---|---|
| 🟦 TypeScript | Documentation | Example |
| 🐍 Python | Documentation | Example |
| ⚡ C++ | Documentation | Example |
| ☕ Java | Documentation | Example |
| #️⃣ C# | Documentation | Example |
| 💜 Kotlin | Documentation | Example |
| 🦀 Rust | Documentation | Example |
| 🐹 Go | Documentation | Example |
| 🎯 Dart | Documentation | Example |
| 🐦 Swift | Documentation | Example |
| ✨ Gleam | Documentation | Example |
| ⚡ Zig | Documentation | Example |
| 🌙 MoonBit | Documentation | Example |