Opus 5.5 Ports the TypeScript Compiler to Rust in 10 Hours for $24,000
Rust Port of TypeScript (Tsc)
An experimental Rust port of the TypeScript 7 compiler, tsc-rs, was built by LLMs. OpenAI models burned over $400,000 in tokens across months and never passed 84% compatibility; Opus 5.5 started from scratch and produced a working v0 in 10 hours for about $24,047. The port passes all 181,711 Go tests and type-checks open-source projects roughly twice as fast as Go.
Opus 5.5 started from scratch. It got further than Astra in 1/10th the time.
- benrutter
> Spent over $400,000 in API priced tokens with GPT-5.6 Sol and GPT 6 Astra
Tangent here, but I think this bit is super interesting!
You could viably hire someone to do this work for that kind of money - I think the interesting thing is that substantially less interested/experimenting engineers would consider paying for a human to do this work, than would happily chuck a big amount of money into an LLM.
I don't have any suggestion about why that exists, but it's a strange and interesting contract.
- wg0
Paraphrasing from README.md:
>Spent over $400,000 in API priced tokens with GPT-5.6 Sol and GPT 6 Astra. They wrote over 1.3m lines of Rust over multiple months of /goal loops and never got past like 84% compat.
Then they let Claude code lose on the problem:
> I figured it'd be fun to throw Opus 5.5 at this. It had a working v0 in 10 hours. I assumed it kept using the code the Codex models wrote. I was wrong. Opus 5.5 started from scratch. It got further than Astra in 1/10th the time.
In the warnings from README.md
> Also worth mentioning: I've never read a line of this code.
- DanRosenwasser
TypeScript team member here - this is impressive work, and it's honestly crazy that 3 of these ports have popped up in the last week! I'm currently AFK but we're hoping to learn more and we'll have more to say on this soon.
- mkesper
What a waste of power... $424.000 of API priced tokens amounts to how many kWh burned? And how would you trust this to build your code?
Motivations says it all:
Motivations
Test model capabilities
Make a fast TypeScript type checker
Make a ts checker that can work in WASM with high performance
Memes
- yoyohello13
Maybe there are just so many of these but at this point for vibe coded stuff like this I’m just like “who cares.” LLMs can make stuff like this now. Unless this reaches some critical mass of usage among developers why would I use it? It’s just a less maintained, less tested implementation. The more important question is “what does this teach us?” And idk the answer to that one.
- shepherdjerred
I wish Anthropic/OpenAI would give me free tokens so I could make random things like this
I already pay for subs on both but the tokens are already spoken for with other projects
- hannibalhorn
In the real world project section, compile times vs tsc7 were 1-3s less. Sometimes the percentages are far more impressive than absolutes.
- spankalee
This was a lot of tokens to spend on a port. I wonder if all of the porting activity out there would be better supported by investing in really good deterministic automatic translators that do 90% of the job cheaply and delegate any decisions that have to be made back out to the AI agent?