Malte UblandClaude Opus 5.5 9a452b8129 Keep replaceable method results that have no dynamic form native
A method whose name an untyped write can replace is called through the
instance's property lookup: a ternary between the dynamic call of an
installed replacement and the native call, both boxed into a dynamic
value and converted back to the method's result type. A result with no
dynamic form, such as an Iterable<T> (its generator arm does not box),
stayed unboxed in the dynamic ternary, which failed IR validation with
"ternary else-branch: expected dyn, got union". Methods of generic class
instantiations always take this path once any write can replace their
name, because their prototype data is not modeled, so importing zod
(whose JavaScript has unknown-key writes) broke every such call.

Such a result now keeps its native type: the native call's value is used
as it is, and only a replacement's dynamic result takes the checked
conversion into the result type. Results that box are lowered as before.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-22 20:24:18 -07:00
2026-10-16 10:33:14 -05:00
2026-10-14 17:27:02 -05:00
2026-07-22 18:08:04 -05:00
2026-10-22 04:10:59 -05:00
2026-07-22 18:08:04 -05:00

scriptc

Vercel Labs Experiment npm version: scriptc License: Apache-2.0 npm downloads per month: 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

Contributing

See CONTRIBUTING.md for source setup, testing, native artifact builds, and docs development.

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