Weld

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WeldA web-service language that compiles to Zig

Statically typed, then native. One toolchain dependency — the Zig compiler.

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Why Weld

Compiles to Zig, then native

hello.weld → hello.zig → a small, static binary via Zig's LLVM-free cross-compiler. Cross-compile to aarch64, riscv64, and more for free.

Routes are the contract

Declare typed routes once; get a type-checked HTTP server and a generated TypeScript/JS client with no drift between server and frontend.

Batteries, written from scratch

Native Postgres (v3 wire protocol), HTTP/HTTPS upstreams, gRPC over from-scratch HTTP/2, WebSocket hubs, JWT — all pure Zig, only std.

A taste ​

weld
type User = { id: int, name: string, email: string? }

route GET "/users/:id" (id: int) -> User {
    respond User { id: id, name: "Ada Lovelace", email: "ada@example.com" }
}
sh
$ weld app.weld --emit bin -O ReleaseFast && ./app &
$ curl localhost:8080/users/42
{"id":42,"name":"Ada Lovelace","email":"ada@example.com"}

You never write JSON: return a record or list and Weld encodes it; return a string and it is sent as text.