Announcing tsc-rs (aka ts-rust), my complete rewrite of the Typescript compiler, type checker, and LSP, all in Rust.
This is a project I've had agents working on for 5 months now. I burned ~$400k of Codex tokens and got nowhere. Burned ~$20k of Opus and got there in 2 weeks.
I have not read a single line of the code.
tsc-rs is an open source drop-in replacement for tsc, and it's available now.
Theo - t3.gg
@theo
Repo is here: github.com/pingdotgg/ts-rust
Full transparency: `bun check` also just dropped. Jarred shared numbers with me early. Incredibly impressive, and probably the right choice for most apps using Bun.
tsc-rs is only faster if you're using the Effect ts checks.
I like this implementation for other reasons, primarily:
- drop-in replacement for tsc
- 100% compatibility (bun errors places tsc-rs and ts7 don't)
- fully wasm-ready
- effect-ts mods built in
Full transparency: `bun check` also just dropped. Jarred shared numbers with me early. Incredibly impressive, and probably the right choice for most apps using Bun.
tsc-rs is only faster if you're using the Effect ts checks.
I like this implementation for other reasons, primarily:
- drop-in replacement for tsc
- 100% compatibility (bun errors places tsc-rs and ts7 don't)
- fully wasm-ready
- effect-ts mods built in
11:07 AM UTC · Oct 7, 2026 · 77.6K Views
204555125
Theo - t3.gg
@theo
Oh shit, didn't realize "bun check" is also missing incremental checks
tsc-rs might actually be the best drop in option rn
tsc-rs might actually be the best drop in option rn
11:36 AM UTC · Oct 7, 2026 · 52.6K Views
5144114
Theo - t3.gg
@theo
I'm going to bed now.
Try this out and lmk how broken it is.
AI is incredible.
Goodnight nerds 🫡
Try this out and lmk how broken it is.
AI is incredible.
Goodnight nerds 🫡
11:41 AM UTC · Oct 7, 2026 · 48K Views
615597