Tsonic

Tsonic compiles a strict, deterministic subset of TypeScript into C#, then builds native binaries or .NET outputs from that generated project.

Stack

• tsonic is the compiler and CLI.
• @tsonic/core provides primitive intent types and compiler intrinsics.
• @tsonic/js is the JavaScript ambient surface.
• @tsonic/nodejs is a first-party TypeScript source package for Node-style modules.
• @tsonic/express is a first-party TypeScript source package for Express-style routing and middleware.
• tsbindgen generates CLR binding packages such as @tsonic/dotnet, @tsonic/aspnetcore, @tsonic/microsoft-extensions, and @tsonic/efcore*.
• Release quality is verified across compiler tests, package selftests, generated binding packages, and downstream applications.

Documentation model

This site mounts product documentation from the owning repositories instead of duplicating it locally.

• tsonic.org owns cross-repo synthesis pages.
• tsonic/docs owns compiler, CLI, workspace, and architecture docs.
• tsbindgen/docs owns generated binding pipeline docs.
• js/docs owns @tsonic/js docs.
• nodejs/docs owns @tsonic/nodejs docs.
• express/docs owns @tsonic/express docs.

Start here

• /architecture/ — architecture and package model
• /ecosystem/ — repo, package, and ownership map
• /testing-and-releases/ — release gates and wave flow
• /tsonic/ — compiler, CLI, workspaces, build modes, examples
• /js/ — @tsonic/js
• /nodejs/ — @tsonic/nodejs
• /express/ — @tsonic/express
• /tsbindgen/ — generated CLR binding packages

Quick starts

CLR-first workspace

mkdir hello-clr
cd hello-clr
tsonic init
tsonic run

import { Console } from "@tsonic/dotnet/System.js";

export function main(): void {
  Console.WriteLine("Hello from Tsonic.");
}

JS-surface workspace

mkdir hello-js
cd hello-js
tsonic init --surface @tsonic/js
tsonic run

export function main(): void {
  const message = "  hello from tsonic  ".trim().toUpperCase();
  console.log(message);
}

JS + Node modules

mkdir hello-node
cd hello-node
tsonic init --surface @tsonic/js
tsonic add npm @tsonic/nodejs
tsonic run

import * as fs from "node:fs";
import * as path from "node:path";

export function main(): void {
  const file = path.join("src", "App.ts");
  console.log(file, fs.existsSync(file));
}

ASP.NET Core workspace

tsonic init
tsonic add framework Microsoft.AspNetCore.App @tsonic/aspnetcore
tsonic restore

import { WebApplication } from "@tsonic/aspnetcore/Microsoft.AspNetCore.Builder.js";
import type { ExtensionMethods } from "@tsonic/aspnetcore/Microsoft.AspNetCore.Builder.js";

export function main(): void {
  const builder = WebApplication.CreateBuilder();
  const app = builder.Build() as ExtensionMethods<WebApplication>;
  app.MapGet("/", () => "Hello from ASP.NET Core");
  app.Run("http://localhost:8080");
}

EF Core + SQLite workspace

tsonic init
tsonic add nuget Microsoft.EntityFrameworkCore.Sqlite 10.0.0 @tsonic/efcore-sqlite
tsonic restore

import { DbContext, DbContextOptionsBuilder } from "@tsonic/efcore/Microsoft.EntityFrameworkCore.js";
import { SqliteDbContextOptionsBuilderExtensions } from "@tsonic/efcore-sqlite/Microsoft.EntityFrameworkCore.js";

export class AppDbContext extends DbContext {
}

export function configure(builder: DbContextOptionsBuilder): void {
  SqliteDbContextOptionsBuilderExtensions.UseSqlite(builder, "Data Source=app.db");
}