#ADR 0000: The harness is written in Rust

Status: accepted, 2026-09-05

#Context

A first version of this harness was designed and built in TypeScript (Hono, Kysely, bun) on 2026-09-05. It reached a green foundation PR and was then discarded the same day. Factory Zero's own projects are Rust; TypeScript was carried over from an unrelated organisation's defaults.

#Decision

Everything in this repository is Rust. Cloudflare Workers are targeted through workers-rs (Rust compiled to wasm32). The self-hosted future is a native Rust binary from the same crates.

#Consequences

Modules are crates; composition is Cargo.toml plus one builder call.
Contributors need rustup, the wasm32-unknown-unknown target and worker-build. The template's CI proves the wasm build on every PR.
The archived TypeScript repositories (*-ts-archived) are reference only.

Mirrored from docs/adr/0000-rust-not-typescript.md at b6f50cd. The harness is the source of truth: a correction goes there first.