scriptc

Zero-runtime TypeScript. scriptc compiles ordinary TypeScript into small, fast native executables — no Node, no V8, no JavaScript engine in the binary.

$ cat fib.ts
function fib(n: number): number {
  return n  ...)`** runs TypeScript at build time (in an isolated VM inside the compiler) and bakes the result into the binary as a literal.
- **Native FFI (`--ffi`)** binds signature-only TypeScript declarations to direct C ABI calls and links manifest-declared archives, objects, and system libraries. The boundary is explicit and length-delimited; see the [Native FFI guide](https://scriptc.dev/ffi).
- **`--dynamic`** embeds the engine for npm deps and `any` code. `scriptc coverage --dynamic` reports exactly which statements run where and what the remaining blockers are. Static stays the default: a binary never silently grows an engine.
- **Checked casts** — `JSON.parse(...) as Config` inserts a runtime validation that throws a catchable error naming the offending path (`expected number at $.port, got string`). TypeScript's `as` is a promise; scriptc verifies it.

## Architecture

```mermaid
flowchart LR
    TS[TypeScript] -->|tsc: parse + typecheck| L[lowering]
    L --> IR[typed IR]
    IR --> C[C]
    C -->|clang| BIN[native executable]

• packages/compiler — frontend (tsc API → IR), the IR with validator/serializer, the LLVM and C backends. The IR is the only interface between the ends; LLVM is the default code generator (with a transparent fallback for programs outside its tier), and C is the reference backend forever (readable, source-line-annotated output via --backend c).
• packages/runtime — the C runtime: refcounted values with a cycle collector, stackful fibers and the event loop (kqueue), the server stack, JS-exact number formatting. Feature units are link-gated: binaries pay only for what they use.
• packages/cli — scriptc build | run | coverage.

Development

$ pnpm install && pnpm build
$ pnpm test                      # differential corpus + diagnostics snapshots
$ SCRIPTC_SAN=1 pnpm test        # the same corpus under ASan + RC audit
$ pnpm scriptc build x.ts --emit-ir   # keep .scriptc/x.c and x.ir.json

Every feature lands with differential tests; both lanes green is the merge bar.