Angular's compiler cannot follow TypeScript into Go
Serguey Asael Shinder2 min readAlex Rickabaugh and Mark Techson have set out what TypeScript 7 means for Angular, and the answer is a rewrite rather than an upgrade. Angular's ahead-of-time compiler was built directly on the TypeScript compiler's APIs, and the team states plainly that this integration cannot work against a Go-compiled TypeScript: there is the cost of crossing the language boundary, and more fundamentally Angular performs its own code transformations through the ts.Transformer API, which does not exist across languages.
The plan, started earlier this year, is to decouple Angular compilation from those APIs altogether. A new Angular-specific compiler takes components, directives and the rest, and emits transformed TypeScript that any build pipeline can then process. The transformation engine is oxc, the Rust toolchain from Void Zero that already powers Vite, chosen for a stable API covering parsing, AST visitation, semantic analysis and transformation. In development the new tool is called the Angular Preprocessor, ngp, to keep it distinct from today's ngc. It has two jobs - compiling decorators and templates into efficient runtime code, and making template expressions type-checkable by the TypeScript compiler - and it emits one output file per job for every input source file.
What it means
The architectural point is more durable than the language choice. Angular is moving from being part of the type checker to producing input for it, which is the same separation most other frameworks in this space settled on years ago: generate code in one tool, type-check in another, and let each side be replaced independently. The reason Angular held out is exactly the reason it now has the most work to do - its compiler was unusually deeply integrated, which bought template type-checking that few competitors matched and cost the ability to move when the host changed implementation language.
Worth being precise about the two languages, because the announcement invites conflation: TypeScript 7 is the Go-based native compiler, and oxc is Rust. Angular is not following TypeScript into Go; it is stepping out of TypeScript's process entirely and picking its own native toolchain. That also means the interesting number for Angular users is not TypeScript 7's benchmark figures but whatever ngp plus a TypeScript 7 type-check costs end to end, and that number does not exist publicly yet. Until it does, this is a well-motivated plan with a named engine and a two-file-per-source output contract - which is considerably more than most "we're rewriting it in Rust" announcements come with.