Each call of a typed or untyped write, writev, transform, flush, final, construct or destroy option callback allocated a closure and a box holding the stream for its `callback` argument. The emitted thunks now take it from scr_stream_done_closure, which keeps the last one on the stream state and hands it out again while the stream holds its only reference and it has no own properties. A callback the user kept (stored, or passed to setImmediate or a promise) is not reused: the next call gets a new closure, and the kept one keeps its own stream reference. The cached closure holds the stream, so the stream drops it when it emits 'close' and traces it, which lets the cycle collector reclaim a stream dropped before it closes. RUNTIME_ABI_VERSION goes from 46 to 47 for scr_stream_done_closure.
scriptc
Compile TypeScript and JavaScript to native executables or WASI WebAssembly modules that run without Node.js installed.
$ cat fib.ts
function fib(n: number): number {
return n < 2 ? n : fib(n - 1) + fib(n - 2);
}
console.log(fib(30));
$ scriptc run fib.ts
832040
$ scriptc build fib.ts -o fib >/dev/null && ./fib
832040
scriptc compiles the same TypeScript you run on Node.js, type-checked by the TypeScript compiler. npm packages your program imports compile along with it. Code scriptc can't compile fails the build with an error code and, where available, a rewrite hint.
scriptc is experimental. See the limitations and the Node.js compatibility reference.
Install
$ npm install -g scriptc
npm installs the native compiler for your platform (macOS, Linux, or Windows). Node.js 24 or later is needed to install it and to run WASI modules with scriptc run; compiling and running executables doesn't need Node.js.
Building executables needs a linker and the platform SDK or sysroot, such as the Xcode Command Line Tools on macOS. Set SCRIPTC_LINKER to choose the linker driver. --emit=ir|llvm|asm|obj needs no external tools. See the quickstart for details.
Commands
scriptc build <file.ts>: compile to a native executable or another artifact selected with--emit.scriptc run <file.ts>: compile and run.scriptc coverage <file.ts>: report what compiles, and explain what doesn't.scriptc build --lib --profile <profile.json>: compile a static library, or a Wasm reactor onwasm32-wasi.
See the CLI reference for every option.
Cross-compilation and WebAssembly
Set SCRIPTC_TARGET to build for another platform, for example SCRIPTC_TARGET=aarch64-linux-gnu.2.36 or SCRIPTC_TARGET=wasm32-wasi. Install the matching @scriptc/runtime-<target> package in your project, at the same version as scriptc --version, or set SCRIPTC_RUNTIME_PACK to a runtime pack directory. See platform support and WebAssembly modules.
Native code
Call C functions by declaring their signatures in TypeScript and binding them to C symbols in a manifest passed with --ffi <manifest.json>. See the Native FFI guide.
Build cache
Builds reuse a bounded persistent cache. Set SCRIPTC_NO_CACHE=1 to bypass it or SCRIPTC_CACHE_DIR to choose its location.
Docs: scriptc.dev