I finished the TypeScript type checker. it's fast

a few years ago I worked on tttt, a TypeScript checker written in C. it never got to production. well, I let a microswarm of Claudes spin on it autonomously for a few weeks, then worked closely with them for a few more. it now it passes ~all the tests, usually works on real-world code and is very fast.

note that the baseline is tsgo, the fast rewrite. original tsc is 5-10X slower.

you (or your guy) can use tttt in your TypeScript projects right now. expect some rough edges. I'd be delighted to hear how it goes :)

npm install --save-dev tttt-ts
./node_modules/@wmww/tttt-ts-linux-x64/bin/tttt
# or npx tttt, but then you'll spend most of the runtime in npx startup

last time I wrote about this project I had a lot of takeaways and lessons. I think the main takeaway now is that Claude can implement TypeScript if you ask nicely. many people are discovering this. bun check, tsrs and tsc-rs were all also built by agents in the past few months.