ts-rust: agents port the TypeScript compiler to Rust
Confirmed
The takeaway
ts-rust (npm package tsc-rs), published by Theo Browne’s company (GitHub org pingdotgg, created Oct 7, 2026; MIT), is a Rust port of Microsoft’s Go-based TypeScript 7 compiler, checker and language server written entirely by LLM agents.
Status
- Claim
Confirmed
- Our reporting
- High confidence
- Importance
- 3 of 5
- Last verified
- 15 October 2026
Your AI and this story
- GPT-6 Astra163 days after its cutoff
- Claude Opus 5.5102 days after its cutoff
- Gemini 4 Argon193 days after its cutoff
- Grok 4.7132 days after its cutoff
None of these four assistants can know about it. The closest, Claude Opus 5.5, stops 102 days before it.
Key facts
- Repo: github.com/pingdotgg/ts-rust, created 2026-10-07, MIT license, ~1.2k stars by Oct 15 (GitHub API)
- README: ‘I used a lot of OpenAI models… 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.’
- README: Opus 5.5 ‘had a working v0 in 10 hours’; ‘Opus 5.5 started from scratch. It got further than Astra in 1/10th the time.’ Total ~$24,047 of API-priced spend over 2 weeks, run on Claude subscriptions at 925–983% of a $200 plan’s weekly limits
- Benchmark in README (T3 Code with Effect diagnostics, sum of medians): tsc-rs --fast 9.77 s, tsc-rs 14.30 s, tsc 7 42.55 s (4.35x / 2.98x faster), bun check 59.24 s, tsc 6 191.00 s
- Author’s caveats: ‘I’ve never read a line of this code’; ‘This is an early release’; the README states 100% compatibility on every real-world project they tested; everything below ‘The Slop Line’ in the README was written by LLMs
- It ports the Go code of microsoft/TypeScript (formerly typescript-go), keeping its algorithms, CLI, language server and API
- Video: Theo, ‘You can rewrite typescript in rust for $420k’ (YouTube, Oct 10; ~170k views by Oct 15)
What happened
Developer and YouTuber Theo (t3.gg) set out to test whether LLM agents could port the TypeScript compiler, type checker and language server from Microsoft’s Go implementation (TypeScript 7) to Rust. The resulting repository, pingdotgg/ts-rust1, went public on Oct 7, 2026 and was explained in a video on Oct 10.
According to the README, months of OpenAI-model agent loops (GPT-5.6 Sol and GPT-6 Astra) cost over $400,000 in API-priced tokens and wrote 1.3M lines of Rust that stalled at about 84% compatibility. Claude Opus 5.5, run through Claude Code subscriptions, ignored that code, started over, reached a working v0 in 10 hours and finished in two weeks for about $24k of API-equivalent usage. The author says he never read the code. The README’s benchmarks show the Rust checker 3–4.35 times faster than tsc 7 on the T3 Code monorepo.
The cost and speed figures are the author’s own and have not been reproduced independently.
Why it matters
It is a large, public, measurable example of agents doing a full compiler migration with no human code review. It also gives a rare head-to-head cost account between frontier coding models on the same task, written by a well-known developer.
Sources
2 sources from 2 sites. Numbers match the chips in the text.
2 sources: 1 primary, 1 reaction
Primary
Reactions
- Theo - t3.gg (YouTube): You can rewrite typescript in rust for $420kyoutube.com, video
Changes
- Filed from data/leads.md (README read via GitHub)