A warm rebuild ran about 3.5 MB of the native compiler's code, but the code was spread over its 69 MB text, so 64 KB fault-around mapped about 20 MB of it. The emitter can now take a function layout: a list of functions in tiers. It writes the listed definitions, generated helpers included, first and by tier, each in a `layout-<tier>` partition group. The LLVM helper compiles each partition's definitions in text order, so the listed ones come first in their partitions, and a helper that places functions by group keeps a tier's definitions in the same partitions. The rest keep their order and their source-file groups. - compile() takes a `functionLayout` file (`<tier> <symbol>` lines, gzip-compressed when the name ends in .gz). Keys leave out module numbers. - build-native-cli.mts uses the committed packages/compiler/native/cli.layout.gz, or the file SCRIPTC_NATIVE_LAYOUT names; an empty value and instrumented builds use none. - scripts/refresh-cli-layout.mjs builds an instrumented compiler, builds the runtime workloads and a corpus slice cold and then unchanged, and reads the functions each run executed from the raw profiles. Tier 1 is `--version` and rebuilds that hit both caches; tier 2 is the other builds. - The release workflow's cli-profile job also collects a layout on the release commit, and the CLI builds use it. Names of closures and generated helpers change with nearby edits, so a committed layout matches fewer functions as main moves on. - Forked lowering and emission workers reset the profile counters after fork and write their profile before _exit, so instrumented builds also count the work done in workers. This applies to refresh-cli-profile.mjs too. Executables the compiler produces are unchanged.
scriptc
scriptc compiles TypeScript and JavaScript to native executables and WebAssembly. It uses the types checked by the TypeScript compiler to generate machine code, and the output runs without Node.js installed. npm packages your program imports compile along with it. Code scriptc can't compile is reported at build time with a diagnostic and, where available, a rewrite hint.
scriptc is experimental and supports a subset of JavaScript, TypeScript, and Node.js APIs. Run scriptc coverage on an existing program to see how much of it compiles, and see the limitations and Node.js compatibility reference for details.
Installation
Install with Node.js 24 or later and npm:
$ npm install -g scriptc
The installed compiler runs natively on macOS, Linux, and Windows. Node.js is needed only to install it and to run WASI modules with scriptc run. Standalone compiler archives are also available from GitHub Releases.
Building executables requires a linker and the platform SDK or 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}`);
scriptc run compiles the file and runs the result:
$ scriptc run hello.ts
hello, world
scriptc build writes an executable:
$ scriptc build hello.ts -o hello >/dev/null
$ ./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 what compiles before you build. 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 >/dev/null
$ ./server
listening on http://localhost:8080
Use npm packages
npm packages compile into the executable with your code, so it doesn't 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 -o cli >/dev/null
$ ./cli
hello from scriptc
Package support is partial. See npm dependencies for which packages compile and how to check them.
Documentation
- Introduction: what scriptc is and what you can build.
- Quickstart: installation and your first executable.
- Coverage reports: check whether an existing program compiles.
- Platform support: cross-compilation and WebAssembly.
- 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.