The cycle analysis gave a header to every type that could reach a cycle, and its construction-only facts gave up on a whole hierarchy as soon as a constructor let `this` escape or a type could cross into checked-dynamic code. Four refinements, all derived from the final IR: - A constructor's stores stay construction-only up to the first top-level statement in which `this` escapes. Statements run in order, so earlier stores complete while the object is private; stores from the escaping statement on, and every store of a constructor whose ancestor let `this` escape, are writes. Compound-assignment receiver temporaries count as `this`. An all-immutable cycle is still impossible: each immutable edge a -> b is stored before a escapes while b has escaped already. - Crossing into checked-dynamic code only makes types mutable when the program contains a runtime store into a dynamic value (int32-slots' audit, now shared as dynamicFieldStores): typed-ref capsules write native fields only through such a commit. Without one, hidden property bags stay empty and add no edges. FFI operands and intrinsics other than publish stay conservative. - A type is traced iff it lies in a cycle-capable component or reaches an intrinsic reference. A type that merely holds a cycle cannot be reached back from it: its references are external counts. - Reachability is per class: a slot of static type C reaches C's subtree, not the whole hierarchy; header presence stays uniform per hierarchy. tsc-ts (e469e33): traced classes 603 -> 469 of 700, records 64 -> 10 of 202, unions 344 -> 93 of 482; scr_cyc_alloc sites 659 -> 471. Mutable hierarchy units 243 -> 4. Collector candidates on the self-check (single-threaded) 6.02M -> 5.55M.
scriptc
scriptc compiles TypeScript and JavaScript to native executables and WebAssembly. It uses TypeScript's type information to compile supported code to native instructions. Static builds run without Node.js or a JavaScript engine.
For npm dependencies and any-typed code, enable --dynamic to include the embedded quickjs-ng engine. Dependency JavaScript is included at build time.
scriptc is experimental and supports a subset of JavaScript, TypeScript, and Node.js APIs. See the limitations and Node.js compatibility reference before using it for an existing project.
Installation
Install with Node.js 24 or later and npm:
$ npm install -g scriptc
The installed compiler runs natively on supported macOS, Linux, and Windows hosts. Native compilation and execution do not require Node.js. Standalone compiler archives are also available from GitHub Releases.
Executable builds require a platform linker and SDK/sysroot. See the quickstart for prerequisites and platform support for host requirements, cross-compilation, and WebAssembly.
Build a program
Create hello.ts:
const who = process.argv.length > 2 ? process.argv[2] : "world";
console.log(`hello, ${who}`);
Compile and run it in one step:
$ scriptc run hello.ts
hello, world
Or write a standalone executable:
$ scriptc build hello.ts -o hello
$ ./hello scriptc
hello, scriptc
These examples use POSIX shell syntax. On Windows, build hello.exe and run it with .\hello.exe.
Use scriptc coverage hello.ts to check which operations compile statically, require dynamic execution, or are unsupported. See coverage reports for details.
Use Node APIs
Supported Node APIs compile to the native runtime. For example, server.ts:
import { createServer } from "node:http";
const server = createServer((req, res) => {
res.setHeader("content-type", "application/json");
res.end(JSON.stringify({ path: req.url }));
});
server.listen(8080, () => {
console.log("listening on http://localhost:8080");
});
$ scriptc build server.ts -o server
$ ./server
listening on http://localhost:8080
Use npm packages
Pass --dynamic to embed an npm package's JavaScript in the executable. The result does not read node_modules at runtime.
Create cli.ts:
import pc from "picocolors";
console.log(pc.green("hello from scriptc"));
$ npm install picocolors
$ scriptc build cli.ts --dynamic -o cli
$ ./cli
hello from scriptc
Enabling --dynamic does not add support for unsupported statically typed calls. See npm dependencies for package resolution and the boundary between static and dynamic code.
Documentation
- Quickstart: installation and your first executable.
- CLI reference: commands, options, and output formats.
- Native program objects: use compiler output in external builds.
- Native FFI: call C ABI functions from compiled programs.
- WebAssembly modules: build and embed WASI modules.
- Examples: programs and integration examples in this repository.
Contributing
See CONTRIBUTING.md for source setup, testing, native artifact builds, and docs development.