Every new runtime entry this wave added landed in a unit that baseline programs link (scr_lib.c's write/copyFile flags, scr_bytes.c's string_decoder dyn forms, scr_events.c's prepend registries and stdin.isRaw, scr_async_dyn.c's uncaught prepend, scr_net.c's server.off). A changed unit changes its object's build-id and symbol metadata even when every retained function is byte-identical, so 1517 corpus programs reported a runtime change for code they never call. Each new entry now lives where only a program that uses it can reach it: - writeFile's `flag` option and the fs/promises twins move to scr_fs_flags.c (feature fsFlags); copyFile's mode form reuses scr_fs_cp.c's reflink walk, so it is that unit's SCR_FS_FLAGS build. - string_decoder's checked-dynamic chunk forms move to scr_bytes_strdec_dyn.c (feature strdecDyn). - the prepend registrations, stdin.isRaw and server.off are the SCR_PROCESS_EXTRAS builds of scr_events.c and scr_async_dyn.c and the SCR_NET_SERVER_OFF build of scr_net.c (feature processExtras). The prepend entry points reuse the append registration and move the new entry to the front, so no existing function changes and every default object stays byte-identical. The Windows copyFile arm stays beside the Win32 path helpers in scr_lib.c, inside its _WIN32 block. The source build (the -O1 -fsanitize=address lane) compiles these units from their sources rather than from the prebuilt pack, so RUNTIME_DEFINES names the same three builds the pack matrix selects. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
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.