An object literal whose get/set accessor satisfies a member the target type
declares as DATA was refused with SC1090: a record member is one storage
slot, so the accessor could only be snapshotted at construction. Node keeps
the accessor live, and the pi sites that hit this (agent.ts:90,
runner.ts:889, codemode/execution.ts:562) are all live getters — one throws
until the object observes later state — so a snapshot is disqualifying.
One static record layout cannot hold both member kinds at one name, so the
analysis marks the TARGET type instead of inventing a literal-only variant:
when a literal's member kind disagrees with the member the contextual type
declares at the same name, that type keeps checked identity, exactly as a
structural type that carries a class instance's identity does. The literal
then lowers through the checked-dynamic literal path, which defines accessor
members as live get/set properties and data members as plain properties, and
reads, writes, Object.keys, `in` and JSON.stringify on the declared type
dispatch dynamically — Node's own model.
The mirrored direction is closed too: a data property satisfying a declared
accessor member (`interface Live { get size(): number }`) used to be an
SC2002 missing-`%get:`-slot refusal; it now keeps the declared type's
identity as well.
Cost, the accepted trade: every value of a MARKED type becomes a checked
dynamic view — a property table and closure dispatch instead of a static
struct slot, so reads and writes on those types are slower (never wrong).
The cost is scoped to the marked type: a program with no such literal marks
nothing, and the frontend analysis itself adds only one array push per object
literal and one Set lookup per data member, with no checker query unless a
member name is an accessor somewhere in the program. IR is byte-identical
for 64 existing corpus programs compiled before and after. The whole-type
accessor-shape form (static reads, closure slots) remains available as the
faster representation if profiles ever show this matters; it needs the
accessor enumeration surfaces (keys, JSON, inspect, for-in, spread, rest)
that this route gets for free.
Only a single object type can be the literal's target: a multi-arm union
picks its arm from the value itself and an intersection merges members, so
neither is marked and both keep today's behavior. A value that reaches the
slot through a variable rather than a literal keeps today's refusal.
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.