main's emitPendingCheck (#785) already tests `scr_exc_active->kind` inline after every may-throw call in executables. The helper and adapter bodies the backend generates (dyn check helpers, async/generator trampolines, inline-async wrappers, FFI callback adapters, island and stream adapters, IPC message thunks, dynamic-key record stores) still called `scr_exc_pending()`, an opaque call into the prebuilt runtime, and so did every runtime C unit. On the tsc-ts self-check that function was about 4% of self time. Those sites now share pendingTestLines, which follows emitPendingCheck's policy: executables load the active cell and compare its i32 kind inline; libraries and worker programs keep the runtime call (workers also observe cross-thread termination there). Runtime units outside thread-instanced libraries and worker executables get the same inline test through a scr_runtime.h macro; the exported scr_exc_pending definition stays for those lanes and for emitted slow paths. A static assert pins the i32 kind at offset 0. This replays the work item's inline-check commit on top of #785: its own emitPendingCheck rewrite is dropped in favor of main's. Adds corpus 4431 pinning exception propagation across fiber switches, generators, sort/map callbacks, and runtime JSON failures.
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.