Chris Tate
67247dd26b
Readable, Writable, Duplex, Transform and PassThrough take the objectMode option, and a Duplex, Transform or PassThrough the readableObjectMode and writableObjectMode options, as true or false literals in an options object literal or in an options value. An object-mode side holds any value that converts to a checked-dynamic value: push, unshift, write, end, pipe, pipeline, for await, 'data' listeners, Readable.from and the transform callback carry values in TypeScript and JavaScript, and constructor-function streams and options held in variables do the same. The object-mode high-water mark counts values and defaults to 16. A readable buffer that mixes strings, Buffers and other values holds them all, and push(undefined) and other values on a byte-mode stream report ERR_INVALID_ARG_TYPE through 'error', as in Node. In typed code a write or transform callback, or a _write or _transform method, may declare its chunk with any such type, which converts when the callback runs. Writes pass the encoding argument to _write and _transform as Node does: undefined when absent, null when a callback took its place, otherwise the value unchanged. A parameter declared string | null | undefined receives that value and one declared string receives "" for undefined and null. write(chunk, encoding) on a byte-mode stream encodes a string chunk with any known encoding and throws ERR_UNKNOWN_ENCODING for an unknown one. Readable.from takes typed Maps and Sets of any such value, and arrays that mix strings and Buffers. for await over a readable-only stream that will emit 'close' now ends after 'close', as Node's eos does. Buffered writes that complete inside clearBuffer run their callbacks in order, and 'finish' waits for a deferred afterWrite that carries a callback, as Node's pendingcb does, unless a _final callback schedules it. The 'data' listener adapters take three slots and write and transform callbacks read their chunk and encoding through runtime accessors, so RUNTIME_ABI_VERSION is now 26.
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.